2c0c9123fc
Including implementing it for `u128`, so it can be defined in `uint_impl!`. This way it works for all backends, including CTFE.
3490 lines
139 KiB
Rust
3490 lines
139 KiB
Rust
macro_rules! uint_impl {
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(
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Self = $SelfT:ty,
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ActualT = $ActualT:ident,
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SignedT = $SignedT:ident,
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// These are all for use *only* in doc comments.
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// As such, they're all passed as literals -- passing them as a string
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// literal is fine if they need to be multiple code tokens.
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// In non-comments, use the associated constants rather than these.
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BITS = $BITS:literal,
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BITS_MINUS_ONE = $BITS_MINUS_ONE:literal,
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MAX = $MaxV:literal,
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rot = $rot:literal,
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rot_op = $rot_op:literal,
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rot_result = $rot_result:literal,
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swap_op = $swap_op:literal,
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swapped = $swapped:literal,
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reversed = $reversed:literal,
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le_bytes = $le_bytes:literal,
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be_bytes = $be_bytes:literal,
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to_xe_bytes_doc = $to_xe_bytes_doc:expr,
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from_xe_bytes_doc = $from_xe_bytes_doc:expr,
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bound_condition = $bound_condition:literal,
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) => {
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/// The smallest value that can be represented by this integer type.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, 0);")]
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/// ```
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#[stable(feature = "assoc_int_consts", since = "1.43.0")]
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pub const MIN: Self = 0;
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/// The largest value that can be represented by this integer type
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#[doc = concat!("(2<sup>", $BITS, "</sup> − 1", $bound_condition, ").")]
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($MaxV), ");")]
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/// ```
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#[stable(feature = "assoc_int_consts", since = "1.43.0")]
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pub const MAX: Self = !0;
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/// The size of this integer type in bits.
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///
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/// # Examples
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///
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/// ```
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#[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")]
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/// ```
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#[stable(feature = "int_bits_const", since = "1.53.0")]
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pub const BITS: u32 = Self::MAX.count_ones();
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/// Returns the number of ones in the binary representation of `self`.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("let n = 0b01001100", stringify!($SelfT), ";")]
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/// assert_eq!(n.count_ones(), 3);
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///
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#[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
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#[doc = concat!("assert_eq!(max.count_ones(), ", stringify!($BITS), ");")]
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///
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#[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
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/// assert_eq!(zero.count_ones(), 0);
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
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#[doc(alias = "popcount")]
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#[doc(alias = "popcnt")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn count_ones(self) -> u32 {
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return intrinsics::ctpop(self);
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}
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/// Returns the number of zeros in the binary representation of `self`.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
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#[doc = concat!("assert_eq!(zero.count_zeros(), ", stringify!($BITS), ");")]
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///
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#[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
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/// assert_eq!(max.count_zeros(), 0);
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn count_zeros(self) -> u32 {
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(!self).count_ones()
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}
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/// Returns the number of leading zeros in the binary representation of `self`.
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///
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/// Depending on what you're doing with the value, you might also be interested in the
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/// [`ilog2`] function which returns a consistent number, even if the type widens.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("let n = ", stringify!($SelfT), "::MAX >> 2;")]
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/// assert_eq!(n.leading_zeros(), 2);
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///
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#[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
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#[doc = concat!("assert_eq!(zero.leading_zeros(), ", stringify!($BITS), ");")]
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///
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#[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
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/// assert_eq!(max.leading_zeros(), 0);
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/// ```
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#[doc = concat!("[`ilog2`]: ", stringify!($SelfT), "::ilog2")]
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#[stable(feature = "rust1", since = "1.0.0")]
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#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn leading_zeros(self) -> u32 {
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return intrinsics::ctlz(self as $ActualT);
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}
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/// Returns the number of trailing zeros in the binary representation
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/// of `self`.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("let n = 0b0101000", stringify!($SelfT), ";")]
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/// assert_eq!(n.trailing_zeros(), 3);
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///
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#[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
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#[doc = concat!("assert_eq!(zero.trailing_zeros(), ", stringify!($BITS), ");")]
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///
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#[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
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#[doc = concat!("assert_eq!(max.trailing_zeros(), 0);")]
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn trailing_zeros(self) -> u32 {
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return intrinsics::cttz(self);
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}
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/// Returns the number of leading ones in the binary representation of `self`.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("let n = !(", stringify!($SelfT), "::MAX >> 2);")]
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/// assert_eq!(n.leading_ones(), 2);
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///
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#[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
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/// assert_eq!(zero.leading_ones(), 0);
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///
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#[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
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#[doc = concat!("assert_eq!(max.leading_ones(), ", stringify!($BITS), ");")]
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/// ```
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#[stable(feature = "leading_trailing_ones", since = "1.46.0")]
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#[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn leading_ones(self) -> u32 {
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(!self).leading_zeros()
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}
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/// Returns the number of trailing ones in the binary representation
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/// of `self`.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("let n = 0b1010111", stringify!($SelfT), ";")]
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/// assert_eq!(n.trailing_ones(), 3);
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///
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#[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
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/// assert_eq!(zero.trailing_ones(), 0);
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///
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#[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
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#[doc = concat!("assert_eq!(max.trailing_ones(), ", stringify!($BITS), ");")]
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/// ```
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#[stable(feature = "leading_trailing_ones", since = "1.46.0")]
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#[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn trailing_ones(self) -> u32 {
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(!self).trailing_zeros()
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}
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/// Returns the bit pattern of `self` reinterpreted as a signed integer of the same size.
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///
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/// This produces the same result as an `as` cast, but ensures that the bit-width remains
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/// the same.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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/// #![feature(integer_sign_cast)]
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///
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#[doc = concat!("let n = ", stringify!($SelfT), "::MAX;")]
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///
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#[doc = concat!("assert_eq!(n.cast_signed(), -1", stringify!($SignedT), ");")]
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/// ```
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#[unstable(feature = "integer_sign_cast", issue = "125882")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn cast_signed(self) -> $SignedT {
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self as $SignedT
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}
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/// Shifts the bits to the left by a specified amount, `n`,
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/// wrapping the truncated bits to the end of the resulting integer.
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///
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/// Please note this isn't the same operation as the `<<` shifting operator!
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
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#[doc = concat!("let m = ", $rot_result, ";")]
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///
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#[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn rotate_left(self, n: u32) -> Self {
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return intrinsics::rotate_left(self, n);
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}
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/// Shifts the bits to the right by a specified amount, `n`,
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/// wrapping the truncated bits to the beginning of the resulting
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/// integer.
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///
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/// Please note this isn't the same operation as the `>>` shifting operator!
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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#[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
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#[doc = concat!("let m = ", $rot_op, ";")]
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///
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#[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn rotate_right(self, n: u32) -> Self {
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return intrinsics::rotate_right(self, n);
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}
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/// Reverses the byte order of the integer.
|
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///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
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///
|
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/// ```
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#[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
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/// let m = n.swap_bytes();
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///
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#[doc = concat!("assert_eq!(m, ", $swapped, ");")]
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline(always)]
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pub const fn swap_bytes(self) -> Self {
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intrinsics::bswap(self as $ActualT) as Self
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}
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/// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
|
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/// second least-significant bit becomes second most-significant bit, etc.
|
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///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
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#[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
|
||
/// let m = n.reverse_bits();
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///
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#[doc = concat!("assert_eq!(m, ", $reversed, ");")]
|
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#[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")]
|
||
/// ```
|
||
#[stable(feature = "reverse_bits", since = "1.37.0")]
|
||
#[rustc_const_stable(feature = "reverse_bits", since = "1.37.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn reverse_bits(self) -> Self {
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intrinsics::bitreverse(self as $ActualT) as Self
|
||
}
|
||
|
||
/// Converts an integer from big endian to the target's endianness.
|
||
///
|
||
/// On big endian this is a no-op. On little endian the bytes are
|
||
/// swapped.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
|
||
///
|
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/// if cfg!(target_endian = "big") {
|
||
#[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n)")]
|
||
/// } else {
|
||
#[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")]
|
||
/// }
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
|
||
#[must_use]
|
||
#[inline(always)]
|
||
pub const fn from_be(x: Self) -> Self {
|
||
#[cfg(target_endian = "big")]
|
||
{
|
||
x
|
||
}
|
||
#[cfg(not(target_endian = "big"))]
|
||
{
|
||
x.swap_bytes()
|
||
}
|
||
}
|
||
|
||
/// Converts an integer from little endian to the target's endianness.
|
||
///
|
||
/// On little endian this is a no-op. On big endian the bytes are
|
||
/// swapped.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
|
||
///
|
||
/// if cfg!(target_endian = "little") {
|
||
#[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n)")]
|
||
/// } else {
|
||
#[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")]
|
||
/// }
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
|
||
#[must_use]
|
||
#[inline(always)]
|
||
pub const fn from_le(x: Self) -> Self {
|
||
#[cfg(target_endian = "little")]
|
||
{
|
||
x
|
||
}
|
||
#[cfg(not(target_endian = "little"))]
|
||
{
|
||
x.swap_bytes()
|
||
}
|
||
}
|
||
|
||
/// Converts `self` to big endian from the target's endianness.
|
||
///
|
||
/// On big endian this is a no-op. On little endian the bytes are
|
||
/// swapped.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
|
||
///
|
||
/// if cfg!(target_endian = "big") {
|
||
/// assert_eq!(n.to_be(), n)
|
||
/// } else {
|
||
/// assert_eq!(n.to_be(), n.swap_bytes())
|
||
/// }
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn to_be(self) -> Self { // or not to be?
|
||
#[cfg(target_endian = "big")]
|
||
{
|
||
self
|
||
}
|
||
#[cfg(not(target_endian = "big"))]
|
||
{
|
||
self.swap_bytes()
|
||
}
|
||
}
|
||
|
||
/// Converts `self` to little endian from the target's endianness.
|
||
///
|
||
/// On little endian this is a no-op. On big endian the bytes are
|
||
/// swapped.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
|
||
///
|
||
/// if cfg!(target_endian = "little") {
|
||
/// assert_eq!(n.to_le(), n)
|
||
/// } else {
|
||
/// assert_eq!(n.to_le(), n.swap_bytes())
|
||
/// }
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn to_le(self) -> Self {
|
||
#[cfg(target_endian = "little")]
|
||
{
|
||
self
|
||
}
|
||
#[cfg(not(target_endian = "little"))]
|
||
{
|
||
self.swap_bytes()
|
||
}
|
||
}
|
||
|
||
/// Checked integer addition. Computes `self + rhs`, returning `None`
|
||
/// if overflow occurred.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!(
|
||
"assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), ",
|
||
"Some(", stringify!($SelfT), "::MAX - 1));"
|
||
)]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_add(self, rhs: Self) -> Option<Self> {
|
||
// This used to use `overflowing_add`, but that means it ends up being
|
||
// a `wrapping_add`, losing some optimization opportunities. Notably,
|
||
// phrasing it this way helps `.checked_add(1)` optimize to a check
|
||
// against `MAX` and a `add nuw`.
|
||
// Per <https://github.com/rust-lang/rust/pull/124114#issuecomment-2066173305>,
|
||
// LLVM is happy to re-form the intrinsic later if useful.
|
||
|
||
if intrinsics::unlikely(intrinsics::add_with_overflow(self, rhs).1) {
|
||
None
|
||
} else {
|
||
// SAFETY: Just checked it doesn't overflow
|
||
Some(unsafe { intrinsics::unchecked_add(self, rhs) })
|
||
}
|
||
}
|
||
|
||
/// Strict integer addition. Computes `self + rhs`, panicking
|
||
/// if overflow occurred.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).strict_add(1), ", stringify!($SelfT), "::MAX - 1);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of overflow:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add(3);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn strict_add(self, rhs: Self) -> Self {
|
||
let (a, b) = self.overflowing_add(rhs);
|
||
if b { overflow_panic::add() } else { a }
|
||
}
|
||
|
||
/// Unchecked integer addition. Computes `self + rhs`, assuming overflow
|
||
/// cannot occur.
|
||
///
|
||
/// Calling `x.unchecked_add(y)` is semantically equivalent to calling
|
||
/// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`.
|
||
///
|
||
/// If you're just trying to avoid the panic in debug mode, then **do not**
|
||
/// use this. Instead, you're looking for [`wrapping_add`].
|
||
///
|
||
/// # Safety
|
||
///
|
||
/// This results in undefined behavior when
|
||
#[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")]
|
||
/// i.e. when [`checked_add`] would return `None`.
|
||
///
|
||
/// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
|
||
#[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")]
|
||
#[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")]
|
||
#[stable(feature = "unchecked_math", since = "1.79.0")]
|
||
#[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
|
||
pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
|
||
assert_unsafe_precondition!(
|
||
check_language_ub,
|
||
concat!(stringify!($SelfT), "::unchecked_add cannot overflow"),
|
||
(
|
||
lhs: $SelfT = self,
|
||
rhs: $SelfT = rhs,
|
||
) => !lhs.overflowing_add(rhs).1,
|
||
);
|
||
|
||
// SAFETY: this is guaranteed to be safe by the caller.
|
||
unsafe {
|
||
intrinsics::unchecked_add(self, rhs)
|
||
}
|
||
}
|
||
|
||
/// Checked addition with a signed integer. Computes `self + rhs`,
|
||
/// returning `None` if overflow occurred.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(2), Some(3));")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(-2), None);")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_signed(3), None);")]
|
||
/// ```
|
||
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
|
||
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_add_signed(self, rhs: $SignedT) -> Option<Self> {
|
||
let (a, b) = self.overflowing_add_signed(rhs);
|
||
if intrinsics::unlikely(b) { None } else { Some(a) }
|
||
}
|
||
|
||
/// Strict addition with a signed integer. Computes `self + rhs`,
|
||
/// panicking if overflow occurred.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_add_signed(2), 3);")]
|
||
/// ```
|
||
///
|
||
/// The following panic because of overflow:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_add_signed(-2);")]
|
||
/// ```
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add_signed(3);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn strict_add_signed(self, rhs: $SignedT) -> Self {
|
||
let (a, b) = self.overflowing_add_signed(rhs);
|
||
if b { overflow_panic::add() } else { a }
|
||
}
|
||
|
||
/// Checked integer subtraction. Computes `self - rhs`, returning
|
||
/// `None` if overflow occurred.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub(1), Some(0));")]
|
||
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_sub(1), None);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
|
||
// Per PR#103299, there's no advantage to the `overflowing` intrinsic
|
||
// for *unsigned* subtraction and we just emit the manual check anyway.
|
||
// Thus, rather than using `overflowing_sub` that produces a wrapping
|
||
// subtraction, check it ourself so we can use an unchecked one.
|
||
|
||
if self < rhs {
|
||
None
|
||
} else {
|
||
// SAFETY: just checked this can't overflow
|
||
Some(unsafe { intrinsics::unchecked_sub(self, rhs) })
|
||
}
|
||
}
|
||
|
||
/// Strict integer subtraction. Computes `self - rhs`, panicking if
|
||
/// overflow occurred.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_sub(1), 0);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of overflow:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = 0", stringify!($SelfT), ".strict_sub(1);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn strict_sub(self, rhs: Self) -> Self {
|
||
let (a, b) = self.overflowing_sub(rhs);
|
||
if b { overflow_panic::sub() } else { a }
|
||
}
|
||
|
||
/// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
|
||
/// cannot occur.
|
||
///
|
||
/// Calling `x.unchecked_sub(y)` is semantically equivalent to calling
|
||
/// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`.
|
||
///
|
||
/// If you're just trying to avoid the panic in debug mode, then **do not**
|
||
/// use this. Instead, you're looking for [`wrapping_sub`].
|
||
///
|
||
/// If you find yourself writing code like this:
|
||
///
|
||
/// ```
|
||
/// # let foo = 30_u32;
|
||
/// # let bar = 20;
|
||
/// if foo >= bar {
|
||
/// // SAFETY: just checked it will not overflow
|
||
/// let diff = unsafe { foo.unchecked_sub(bar) };
|
||
/// // ... use diff ...
|
||
/// }
|
||
/// ```
|
||
///
|
||
/// Consider changing it to
|
||
///
|
||
/// ```
|
||
/// # let foo = 30_u32;
|
||
/// # let bar = 20;
|
||
/// if let Some(diff) = foo.checked_sub(bar) {
|
||
/// // ... use diff ...
|
||
/// }
|
||
/// ```
|
||
///
|
||
/// As that does exactly the same thing -- including telling the optimizer
|
||
/// that the subtraction cannot overflow -- but avoids needing `unsafe`.
|
||
///
|
||
/// # Safety
|
||
///
|
||
/// This results in undefined behavior when
|
||
#[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")]
|
||
/// i.e. when [`checked_sub`] would return `None`.
|
||
///
|
||
/// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
|
||
#[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")]
|
||
#[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")]
|
||
#[stable(feature = "unchecked_math", since = "1.79.0")]
|
||
#[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
|
||
pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
|
||
assert_unsafe_precondition!(
|
||
check_language_ub,
|
||
concat!(stringify!($SelfT), "::unchecked_sub cannot overflow"),
|
||
(
|
||
lhs: $SelfT = self,
|
||
rhs: $SelfT = rhs,
|
||
) => !lhs.overflowing_sub(rhs).1,
|
||
);
|
||
|
||
// SAFETY: this is guaranteed to be safe by the caller.
|
||
unsafe {
|
||
intrinsics::unchecked_sub(self, rhs)
|
||
}
|
||
}
|
||
|
||
/// Checked subtraction with a signed integer. Computes `self - rhs`,
|
||
/// returning `None` if overflow occurred.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(mixed_integer_ops_unsigned_sub)]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_signed(2), None);")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_signed(-2), Some(3));")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_sub_signed(-4), None);")]
|
||
/// ```
|
||
#[unstable(feature = "mixed_integer_ops_unsigned_sub", issue = "126043")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_sub_signed(self, rhs: $SignedT) -> Option<Self> {
|
||
let (res, overflow) = self.overflowing_sub_signed(rhs);
|
||
|
||
if !overflow {
|
||
Some(res)
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
#[doc = concat!(
|
||
"Checked integer subtraction. Computes `self - rhs` and checks if the result fits into an [`",
|
||
stringify!($SignedT), "`], returning `None` if overflow occurred."
|
||
)]
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(unsigned_signed_diff)]
|
||
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_signed_diff(2), Some(8));")]
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_signed_diff(10), Some(-8));")]
|
||
#[doc = concat!(
|
||
"assert_eq!(",
|
||
stringify!($SelfT),
|
||
"::MAX.checked_signed_diff(",
|
||
stringify!($SignedT),
|
||
"::MAX as ",
|
||
stringify!($SelfT),
|
||
"), None);"
|
||
)]
|
||
#[doc = concat!(
|
||
"assert_eq!((",
|
||
stringify!($SignedT),
|
||
"::MAX as ",
|
||
stringify!($SelfT),
|
||
").checked_signed_diff(",
|
||
stringify!($SelfT),
|
||
"::MAX), Some(",
|
||
stringify!($SignedT),
|
||
"::MIN));"
|
||
)]
|
||
#[doc = concat!(
|
||
"assert_eq!((",
|
||
stringify!($SignedT),
|
||
"::MAX as ",
|
||
stringify!($SelfT),
|
||
" + 1).checked_signed_diff(0), None);"
|
||
)]
|
||
#[doc = concat!(
|
||
"assert_eq!(",
|
||
stringify!($SelfT),
|
||
"::MAX.checked_signed_diff(",
|
||
stringify!($SelfT),
|
||
"::MAX), Some(0));"
|
||
)]
|
||
/// ```
|
||
#[unstable(feature = "unsigned_signed_diff", issue = "126041")]
|
||
#[inline]
|
||
pub const fn checked_signed_diff(self, rhs: Self) -> Option<$SignedT> {
|
||
let res = self.wrapping_sub(rhs) as $SignedT;
|
||
let overflow = (self >= rhs) == (res < 0);
|
||
|
||
if !overflow {
|
||
Some(res)
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
/// Checked integer multiplication. Computes `self * rhs`, returning
|
||
/// `None` if overflow occurred.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_mul(1), Some(5));")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_mul(self, rhs: Self) -> Option<Self> {
|
||
let (a, b) = self.overflowing_mul(rhs);
|
||
if intrinsics::unlikely(b) { None } else { Some(a) }
|
||
}
|
||
|
||
/// Strict integer multiplication. Computes `self * rhs`, panicking if
|
||
/// overflow occurred.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_mul(1), 5);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of overflow:
|
||
///
|
||
/// ``` should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_mul(2);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn strict_mul(self, rhs: Self) -> Self {
|
||
let (a, b) = self.overflowing_mul(rhs);
|
||
if b { overflow_panic::mul() } else { a }
|
||
}
|
||
|
||
/// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
|
||
/// cannot occur.
|
||
///
|
||
/// Calling `x.unchecked_mul(y)` is semantically equivalent to calling
|
||
/// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`.
|
||
///
|
||
/// If you're just trying to avoid the panic in debug mode, then **do not**
|
||
/// use this. Instead, you're looking for [`wrapping_mul`].
|
||
///
|
||
/// # Safety
|
||
///
|
||
/// This results in undefined behavior when
|
||
#[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")]
|
||
/// i.e. when [`checked_mul`] would return `None`.
|
||
///
|
||
/// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
|
||
#[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")]
|
||
#[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")]
|
||
#[stable(feature = "unchecked_math", since = "1.79.0")]
|
||
#[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
|
||
pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
|
||
assert_unsafe_precondition!(
|
||
check_language_ub,
|
||
concat!(stringify!($SelfT), "::unchecked_mul cannot overflow"),
|
||
(
|
||
lhs: $SelfT = self,
|
||
rhs: $SelfT = rhs,
|
||
) => !lhs.overflowing_mul(rhs).1,
|
||
);
|
||
|
||
// SAFETY: this is guaranteed to be safe by the caller.
|
||
unsafe {
|
||
intrinsics::unchecked_mul(self, rhs)
|
||
}
|
||
}
|
||
|
||
/// Checked integer division. Computes `self / rhs`, returning `None`
|
||
/// if `rhs == 0`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div(2), Some(64));")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div(0), None);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_div(self, rhs: Self) -> Option<Self> {
|
||
if intrinsics::unlikely(rhs == 0) {
|
||
None
|
||
} else {
|
||
// SAFETY: div by zero has been checked above and unsigned types have no other
|
||
// failure modes for division
|
||
Some(unsafe { intrinsics::unchecked_div(self, rhs) })
|
||
}
|
||
}
|
||
|
||
/// Strict integer division. Computes `self / rhs`.
|
||
///
|
||
/// Strict division on unsigned types is just normal division. There's no
|
||
/// way overflow could ever happen. This function exists so that all
|
||
/// operations are accounted for in the strict operations.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_div(10), 10);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of division by zero:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div(0);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn strict_div(self, rhs: Self) -> Self {
|
||
self / rhs
|
||
}
|
||
|
||
/// Checked Euclidean division. Computes `self.div_euclid(rhs)`, returning `None`
|
||
/// if `rhs == 0`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div_euclid(2), Some(64));")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div_euclid(0), None);")]
|
||
/// ```
|
||
#[stable(feature = "euclidean_division", since = "1.38.0")]
|
||
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
|
||
if intrinsics::unlikely(rhs == 0) {
|
||
None
|
||
} else {
|
||
Some(self.div_euclid(rhs))
|
||
}
|
||
}
|
||
|
||
/// Strict Euclidean division. Computes `self.div_euclid(rhs)`.
|
||
///
|
||
/// Strict division on unsigned types is just normal division. There's no
|
||
/// way overflow could ever happen. This function exists so that all
|
||
/// operations are accounted for in the strict operations. Since, for the
|
||
/// positive integers, all common definitions of division are equal, this
|
||
/// is exactly equal to `self.strict_div(rhs)`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_div_euclid(10), 10);")]
|
||
/// ```
|
||
/// The following panics because of division by zero:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div_euclid(0);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn strict_div_euclid(self, rhs: Self) -> Self {
|
||
self / rhs
|
||
}
|
||
|
||
/// Checked integer remainder. Computes `self % rhs`, returning `None`
|
||
/// if `rhs == 0`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")]
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
|
||
if intrinsics::unlikely(rhs == 0) {
|
||
None
|
||
} else {
|
||
// SAFETY: div by zero has been checked above and unsigned types have no other
|
||
// failure modes for division
|
||
Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
|
||
}
|
||
}
|
||
|
||
/// Strict integer remainder. Computes `self % rhs`.
|
||
///
|
||
/// Strict remainder calculation on unsigned types is just the regular
|
||
/// remainder calculation. There's no way overflow could ever happen.
|
||
/// This function exists so that all operations are accounted for in the
|
||
/// strict operations.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_rem(10), 0);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of division by zero:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem(0);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn strict_rem(self, rhs: Self) -> Self {
|
||
self % rhs
|
||
}
|
||
|
||
/// Checked Euclidean modulo. Computes `self.rem_euclid(rhs)`, returning `None`
|
||
/// if `rhs == 0`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")]
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")]
|
||
/// ```
|
||
#[stable(feature = "euclidean_division", since = "1.38.0")]
|
||
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
|
||
if intrinsics::unlikely(rhs == 0) {
|
||
None
|
||
} else {
|
||
Some(self.rem_euclid(rhs))
|
||
}
|
||
}
|
||
|
||
/// Strict Euclidean modulo. Computes `self.rem_euclid(rhs)`.
|
||
///
|
||
/// Strict modulo calculation on unsigned types is just the regular
|
||
/// remainder calculation. There's no way overflow could ever happen.
|
||
/// This function exists so that all operations are accounted for in the
|
||
/// strict operations. Since, for the positive integers, all common
|
||
/// definitions of division are equal, this is exactly equal to
|
||
/// `self.strict_rem(rhs)`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_rem_euclid(10), 0);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of division by zero:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem_euclid(0);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn strict_rem_euclid(self, rhs: Self) -> Self {
|
||
self % rhs
|
||
}
|
||
|
||
/// Returns the logarithm of the number with respect to an arbitrary base,
|
||
/// rounded down.
|
||
///
|
||
/// This method might not be optimized owing to implementation details;
|
||
/// `ilog2` can produce results more efficiently for base 2, and `ilog10`
|
||
/// can produce results more efficiently for base 10.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `self` is zero, or if `base` is less than 2.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")]
|
||
/// ```
|
||
#[stable(feature = "int_log", since = "1.67.0")]
|
||
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn ilog(self, base: Self) -> u32 {
|
||
assert!(base >= 2, "base of integer logarithm must be at least 2");
|
||
if let Some(log) = self.checked_ilog(base) {
|
||
log
|
||
} else {
|
||
int_log10::panic_for_nonpositive_argument()
|
||
}
|
||
}
|
||
|
||
/// Returns the base 2 logarithm of the number, rounded down.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `self` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")]
|
||
/// ```
|
||
#[stable(feature = "int_log", since = "1.67.0")]
|
||
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn ilog2(self) -> u32 {
|
||
if let Some(log) = self.checked_ilog2() {
|
||
log
|
||
} else {
|
||
int_log10::panic_for_nonpositive_argument()
|
||
}
|
||
}
|
||
|
||
/// Returns the base 10 logarithm of the number, rounded down.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `self` is zero.
|
||
///
|
||
/// # Example
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")]
|
||
/// ```
|
||
#[stable(feature = "int_log", since = "1.67.0")]
|
||
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn ilog10(self) -> u32 {
|
||
if let Some(log) = self.checked_ilog10() {
|
||
log
|
||
} else {
|
||
int_log10::panic_for_nonpositive_argument()
|
||
}
|
||
}
|
||
|
||
/// Returns the logarithm of the number with respect to an arbitrary base,
|
||
/// rounded down.
|
||
///
|
||
/// Returns `None` if the number is zero, or if the base is not at least 2.
|
||
///
|
||
/// This method might not be optimized owing to implementation details;
|
||
/// `checked_ilog2` can produce results more efficiently for base 2, and
|
||
/// `checked_ilog10` can produce results more efficiently for base 10.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")]
|
||
/// ```
|
||
#[stable(feature = "int_log", since = "1.67.0")]
|
||
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_ilog(self, base: Self) -> Option<u32> {
|
||
if self <= 0 || base <= 1 {
|
||
None
|
||
} else if self < base {
|
||
Some(0)
|
||
} else {
|
||
// Since base >= self, n >= 1
|
||
let mut n = 1;
|
||
let mut r = base;
|
||
|
||
// Optimization for 128 bit wide integers.
|
||
if Self::BITS == 128 {
|
||
// The following is a correct lower bound for ⌊log(base,self)⌋ because
|
||
//
|
||
// log(base,self) = log(2,self) / log(2,base)
|
||
// ≥ ⌊log(2,self)⌋ / (⌊log(2,base)⌋ + 1)
|
||
//
|
||
// hence
|
||
//
|
||
// ⌊log(base,self)⌋ ≥ ⌊ ⌊log(2,self)⌋ / (⌊log(2,base)⌋ + 1) ⌋ .
|
||
n = self.ilog2() / (base.ilog2() + 1);
|
||
r = base.pow(n);
|
||
}
|
||
|
||
while r <= self / base {
|
||
n += 1;
|
||
r *= base;
|
||
}
|
||
Some(n)
|
||
}
|
||
}
|
||
|
||
/// Returns the base 2 logarithm of the number, rounded down.
|
||
///
|
||
/// Returns `None` if the number is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")]
|
||
/// ```
|
||
#[stable(feature = "int_log", since = "1.67.0")]
|
||
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_ilog2(self) -> Option<u32> {
|
||
match NonZero::new(self) {
|
||
Some(x) => Some(x.ilog2()),
|
||
None => None,
|
||
}
|
||
}
|
||
|
||
/// Returns the base 10 logarithm of the number, rounded down.
|
||
///
|
||
/// Returns `None` if the number is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")]
|
||
/// ```
|
||
#[stable(feature = "int_log", since = "1.67.0")]
|
||
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_ilog10(self) -> Option<u32> {
|
||
match NonZero::new(self) {
|
||
Some(x) => Some(x.ilog10()),
|
||
None => None,
|
||
}
|
||
}
|
||
|
||
/// Checked negation. Computes `-self`, returning `None` unless `self ==
|
||
/// 0`.
|
||
///
|
||
/// Note that negating any positive integer will overflow.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_neg(), Some(0));")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_neg(), None);")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_neg(self) -> Option<Self> {
|
||
let (a, b) = self.overflowing_neg();
|
||
if intrinsics::unlikely(b) { None } else { Some(a) }
|
||
}
|
||
|
||
/// Strict negation. Computes `-self`, panicking unless `self ==
|
||
/// 0`.
|
||
///
|
||
/// Note that negating any positive integer will overflow.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".strict_neg(), 0);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of overflow:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_neg();")]
|
||
///
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn strict_neg(self) -> Self {
|
||
let (a, b) = self.overflowing_neg();
|
||
if b { overflow_panic::neg() } else { a }
|
||
}
|
||
|
||
/// Checked shift left. Computes `self << rhs`, returning `None`
|
||
/// if `rhs` is larger than or equal to the number of bits in `self`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(129), None);")]
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(", stringify!($BITS_MINUS_ONE), "), Some(0));")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
|
||
// Not using overflowing_shl as that's a wrapping shift
|
||
if rhs < Self::BITS {
|
||
// SAFETY: just checked the RHS is in-range
|
||
Some(unsafe { self.unchecked_shl(rhs) })
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
/// Strict shift left. Computes `self << rhs`, panicking if `rhs` is larger
|
||
/// than or equal to the number of bits in `self`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".strict_shl(4), 0x10);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of overflow:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shl(129);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn strict_shl(self, rhs: u32) -> Self {
|
||
let (a, b) = self.overflowing_shl(rhs);
|
||
if b { overflow_panic::shl() } else { a }
|
||
}
|
||
|
||
/// Unchecked shift left. Computes `self << rhs`, assuming that
|
||
/// `rhs` is less than the number of bits in `self`.
|
||
///
|
||
/// # Safety
|
||
///
|
||
/// This results in undefined behavior if `rhs` is larger than
|
||
/// or equal to the number of bits in `self`,
|
||
/// i.e. when [`checked_shl`] would return `None`.
|
||
///
|
||
#[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")]
|
||
#[unstable(
|
||
feature = "unchecked_shifts",
|
||
reason = "niche optimization path",
|
||
issue = "85122",
|
||
)]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
|
||
pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self {
|
||
assert_unsafe_precondition!(
|
||
check_language_ub,
|
||
concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"),
|
||
(
|
||
rhs: u32 = rhs,
|
||
) => rhs < <$ActualT>::BITS,
|
||
);
|
||
|
||
// SAFETY: this is guaranteed to be safe by the caller.
|
||
unsafe {
|
||
intrinsics::unchecked_shl(self, rhs)
|
||
}
|
||
}
|
||
|
||
/// Unbounded shift left. Computes `self << rhs`, without bounding the value of `rhs`.
|
||
///
|
||
/// If `rhs` is larger or equal to the number of bits in `self`,
|
||
/// the entire value is shifted out, and `0` is returned.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
/// ```
|
||
/// #![feature(unbounded_shifts)]
|
||
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".unbounded_shl(4), 0x10);")]
|
||
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".unbounded_shl(129), 0);")]
|
||
/// ```
|
||
#[unstable(feature = "unbounded_shifts", issue = "129375")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn unbounded_shl(self, rhs: u32) -> $SelfT{
|
||
if rhs < Self::BITS {
|
||
// SAFETY:
|
||
// rhs is just checked to be in-range above
|
||
unsafe { self.unchecked_shl(rhs) }
|
||
} else {
|
||
0
|
||
}
|
||
}
|
||
|
||
/// Checked shift right. Computes `self >> rhs`, returning `None`
|
||
/// if `rhs` is larger than or equal to the number of bits in `self`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")]
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(129), None);")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
|
||
// Not using overflowing_shr as that's a wrapping shift
|
||
if rhs < Self::BITS {
|
||
// SAFETY: just checked the RHS is in-range
|
||
Some(unsafe { self.unchecked_shr(rhs) })
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
/// Strict shift right. Computes `self >> rhs`, panicking `rhs` is
|
||
/// larger than or equal to the number of bits in `self`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".strict_shr(4), 0x1);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of overflow:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shr(129);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn strict_shr(self, rhs: u32) -> Self {
|
||
let (a, b) = self.overflowing_shr(rhs);
|
||
if b { overflow_panic::shr() } else { a }
|
||
}
|
||
|
||
/// Unchecked shift right. Computes `self >> rhs`, assuming that
|
||
/// `rhs` is less than the number of bits in `self`.
|
||
///
|
||
/// # Safety
|
||
///
|
||
/// This results in undefined behavior if `rhs` is larger than
|
||
/// or equal to the number of bits in `self`,
|
||
/// i.e. when [`checked_shr`] would return `None`.
|
||
///
|
||
#[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")]
|
||
#[unstable(
|
||
feature = "unchecked_shifts",
|
||
reason = "niche optimization path",
|
||
issue = "85122",
|
||
)]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
|
||
pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self {
|
||
assert_unsafe_precondition!(
|
||
check_language_ub,
|
||
concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"),
|
||
(
|
||
rhs: u32 = rhs,
|
||
) => rhs < <$ActualT>::BITS,
|
||
);
|
||
|
||
// SAFETY: this is guaranteed to be safe by the caller.
|
||
unsafe {
|
||
intrinsics::unchecked_shr(self, rhs)
|
||
}
|
||
}
|
||
|
||
/// Unbounded shift right. Computes `self >> rhs`, without bounding the value of `rhs`.
|
||
///
|
||
/// If `rhs` is larger or equal to the number of bits in `self`,
|
||
/// the entire value is shifted out, and `0` is returned.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
/// ```
|
||
/// #![feature(unbounded_shifts)]
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".unbounded_shr(4), 0x1);")]
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".unbounded_shr(129), 0);")]
|
||
/// ```
|
||
#[unstable(feature = "unbounded_shifts", issue = "129375")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn unbounded_shr(self, rhs: u32) -> $SelfT{
|
||
if rhs < Self::BITS {
|
||
// SAFETY:
|
||
// rhs is just checked to be in-range above
|
||
unsafe { self.unchecked_shr(rhs) }
|
||
} else {
|
||
0
|
||
}
|
||
}
|
||
|
||
/// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
|
||
/// overflow occurred.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_pow(5), Some(32));")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")]
|
||
/// ```
|
||
#[stable(feature = "no_panic_pow", since = "1.34.0")]
|
||
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
|
||
if exp == 0 {
|
||
return Some(1);
|
||
}
|
||
let mut base = self;
|
||
let mut acc: Self = 1;
|
||
|
||
loop {
|
||
if (exp & 1) == 1 {
|
||
acc = try_opt!(acc.checked_mul(base));
|
||
// since exp!=0, finally the exp must be 1.
|
||
if exp == 1 {
|
||
return Some(acc);
|
||
}
|
||
}
|
||
exp /= 2;
|
||
base = try_opt!(base.checked_mul(base));
|
||
}
|
||
}
|
||
|
||
/// Strict exponentiation. Computes `self.pow(exp)`, panicking if
|
||
/// overflow occurred.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".strict_pow(5), 32);")]
|
||
/// ```
|
||
///
|
||
/// The following panics because of overflow:
|
||
///
|
||
/// ```should_panic
|
||
/// #![feature(strict_overflow_ops)]
|
||
#[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_pow(2);")]
|
||
/// ```
|
||
#[unstable(feature = "strict_overflow_ops", issue = "118260")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn strict_pow(self, mut exp: u32) -> Self {
|
||
if exp == 0 {
|
||
return 1;
|
||
}
|
||
let mut base = self;
|
||
let mut acc: Self = 1;
|
||
|
||
loop {
|
||
if (exp & 1) == 1 {
|
||
acc = acc.strict_mul(base);
|
||
// since exp!=0, finally the exp must be 1.
|
||
if exp == 1 {
|
||
return acc;
|
||
}
|
||
}
|
||
exp /= 2;
|
||
base = base.strict_mul(base);
|
||
}
|
||
}
|
||
|
||
/// Saturating integer addition. Computes `self + rhs`, saturating at
|
||
/// the numeric bounds instead of overflowing.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(127), ", stringify!($SelfT), "::MAX);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
|
||
#[inline(always)]
|
||
pub const fn saturating_add(self, rhs: Self) -> Self {
|
||
intrinsics::saturating_add(self, rhs)
|
||
}
|
||
|
||
/// Saturating addition with a signed integer. Computes `self + rhs`,
|
||
/// saturating at the numeric bounds instead of overflowing.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(2), 3);")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(-2), 0);")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_add_signed(4), ", stringify!($SelfT), "::MAX);")]
|
||
/// ```
|
||
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
|
||
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn saturating_add_signed(self, rhs: $SignedT) -> Self {
|
||
let (res, overflow) = self.overflowing_add(rhs as Self);
|
||
if overflow == (rhs < 0) {
|
||
res
|
||
} else if overflow {
|
||
Self::MAX
|
||
} else {
|
||
0
|
||
}
|
||
}
|
||
|
||
/// Saturating integer subtraction. Computes `self - rhs`, saturating
|
||
/// at the numeric bounds instead of overflowing.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(27), 73);")]
|
||
#[doc = concat!("assert_eq!(13", stringify!($SelfT), ".saturating_sub(127), 0);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
|
||
#[inline(always)]
|
||
pub const fn saturating_sub(self, rhs: Self) -> Self {
|
||
intrinsics::saturating_sub(self, rhs)
|
||
}
|
||
|
||
/// Saturating integer subtraction. Computes `self` - `rhs`, saturating at
|
||
/// the numeric bounds instead of overflowing.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(mixed_integer_ops_unsigned_sub)]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_sub_signed(2), 0);")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_sub_signed(-2), 3);")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_sub_signed(-4), ", stringify!($SelfT), "::MAX);")]
|
||
/// ```
|
||
#[unstable(feature = "mixed_integer_ops_unsigned_sub", issue = "126043")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn saturating_sub_signed(self, rhs: $SignedT) -> Self {
|
||
let (res, overflow) = self.overflowing_sub_signed(rhs);
|
||
|
||
if !overflow {
|
||
res
|
||
} else if rhs < 0 {
|
||
Self::MAX
|
||
} else {
|
||
0
|
||
}
|
||
}
|
||
|
||
/// Saturating integer multiplication. Computes `self * rhs`,
|
||
/// saturating at the numeric bounds instead of overflowing.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".saturating_mul(10), 20);")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).saturating_mul(10), ", stringify!($SelfT),"::MAX);")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn saturating_mul(self, rhs: Self) -> Self {
|
||
match self.checked_mul(rhs) {
|
||
Some(x) => x,
|
||
None => Self::MAX,
|
||
}
|
||
}
|
||
|
||
/// Saturating integer division. Computes `self / rhs`, saturating at the
|
||
/// numeric bounds instead of overflowing.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")]
|
||
///
|
||
/// ```
|
||
#[stable(feature = "saturating_div", since = "1.58.0")]
|
||
#[rustc_const_stable(feature = "saturating_div", since = "1.58.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn saturating_div(self, rhs: Self) -> Self {
|
||
// on unsigned types, there is no overflow in integer division
|
||
self.wrapping_div(rhs)
|
||
}
|
||
|
||
/// Saturating integer exponentiation. Computes `self.pow(exp)`,
|
||
/// saturating at the numeric bounds instead of overflowing.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(4", stringify!($SelfT), ".saturating_pow(3), 64);")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
|
||
/// ```
|
||
#[stable(feature = "no_panic_pow", since = "1.34.0")]
|
||
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn saturating_pow(self, exp: u32) -> Self {
|
||
match self.checked_pow(exp) {
|
||
Some(x) => x,
|
||
None => Self::MAX,
|
||
}
|
||
}
|
||
|
||
/// Wrapping (modular) addition. Computes `self + rhs`,
|
||
/// wrapping around at the boundary of the type.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(55), 255);")]
|
||
#[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(", stringify!($SelfT), "::MAX), 199);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn wrapping_add(self, rhs: Self) -> Self {
|
||
intrinsics::wrapping_add(self, rhs)
|
||
}
|
||
|
||
/// Wrapping (modular) addition with a signed integer. Computes
|
||
/// `self + rhs`, wrapping around at the boundary of the type.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(2), 3);")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(-2), ", stringify!($SelfT), "::MAX);")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_add_signed(4), 1);")]
|
||
/// ```
|
||
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
|
||
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn wrapping_add_signed(self, rhs: $SignedT) -> Self {
|
||
self.wrapping_add(rhs as Self)
|
||
}
|
||
|
||
/// Wrapping (modular) subtraction. Computes `self - rhs`,
|
||
/// wrapping around at the boundary of the type.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(100), 0);")]
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(", stringify!($SelfT), "::MAX), 101);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn wrapping_sub(self, rhs: Self) -> Self {
|
||
intrinsics::wrapping_sub(self, rhs)
|
||
}
|
||
|
||
/// Wrapping (modular) subtraction with a signed integer. Computes
|
||
/// `self - rhs`, wrapping around at the boundary of the type.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(mixed_integer_ops_unsigned_sub)]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_sub_signed(2), ", stringify!($SelfT), "::MAX);")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_sub_signed(-2), 3);")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_sub_signed(-4), 1);")]
|
||
/// ```
|
||
#[unstable(feature = "mixed_integer_ops_unsigned_sub", issue = "126043")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn wrapping_sub_signed(self, rhs: $SignedT) -> Self {
|
||
self.wrapping_sub(rhs as Self)
|
||
}
|
||
|
||
/// Wrapping (modular) multiplication. Computes `self *
|
||
/// rhs`, wrapping around at the boundary of the type.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// Please note that this example is shared between integer types.
|
||
/// Which explains why `u8` is used here.
|
||
///
|
||
/// ```
|
||
/// assert_eq!(10u8.wrapping_mul(12), 120);
|
||
/// assert_eq!(25u8.wrapping_mul(12), 44);
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn wrapping_mul(self, rhs: Self) -> Self {
|
||
intrinsics::wrapping_mul(self, rhs)
|
||
}
|
||
|
||
/// Wrapping (modular) division. Computes `self / rhs`.
|
||
///
|
||
/// Wrapped division on unsigned types is just normal division. There's
|
||
/// no way wrapping could ever happen. This function exists so that all
|
||
/// operations are accounted for in the wrapping operations.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
|
||
/// ```
|
||
#[stable(feature = "num_wrapping", since = "1.2.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn wrapping_div(self, rhs: Self) -> Self {
|
||
self / rhs
|
||
}
|
||
|
||
/// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`.
|
||
///
|
||
/// Wrapped division on unsigned types is just normal division. There's
|
||
/// no way wrapping could ever happen. This function exists so that all
|
||
/// operations are accounted for in the wrapping operations. Since, for
|
||
/// the positive integers, all common definitions of division are equal,
|
||
/// this is exactly equal to `self.wrapping_div(rhs)`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")]
|
||
/// ```
|
||
#[stable(feature = "euclidean_division", since = "1.38.0")]
|
||
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn wrapping_div_euclid(self, rhs: Self) -> Self {
|
||
self / rhs
|
||
}
|
||
|
||
/// Wrapping (modular) remainder. Computes `self % rhs`.
|
||
///
|
||
/// Wrapped remainder calculation on unsigned types is just the regular
|
||
/// remainder calculation. There's no way wrapping could ever happen.
|
||
/// This function exists so that all operations are accounted for in the
|
||
/// wrapping operations.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
|
||
/// ```
|
||
#[stable(feature = "num_wrapping", since = "1.2.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn wrapping_rem(self, rhs: Self) -> Self {
|
||
self % rhs
|
||
}
|
||
|
||
/// Wrapping Euclidean modulo. Computes `self.rem_euclid(rhs)`.
|
||
///
|
||
/// Wrapped modulo calculation on unsigned types is just the regular
|
||
/// remainder calculation. There's no way wrapping could ever happen.
|
||
/// This function exists so that all operations are accounted for in the
|
||
/// wrapping operations. Since, for the positive integers, all common
|
||
/// definitions of division are equal, this is exactly equal to
|
||
/// `self.wrapping_rem(rhs)`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")]
|
||
/// ```
|
||
#[stable(feature = "euclidean_division", since = "1.38.0")]
|
||
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self {
|
||
self % rhs
|
||
}
|
||
|
||
/// Wrapping (modular) negation. Computes `-self`,
|
||
/// wrapping around at the boundary of the type.
|
||
///
|
||
/// Since unsigned types do not have negative equivalents
|
||
/// all applications of this function will wrap (except for `-0`).
|
||
/// For values smaller than the corresponding signed type's maximum
|
||
/// the result is the same as casting the corresponding signed value.
|
||
/// Any larger values are equivalent to `MAX + 1 - (val - MAX - 1)` where
|
||
/// `MAX` is the corresponding signed type's maximum.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".wrapping_neg(), 0);")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_neg(), 1);")]
|
||
#[doc = concat!("assert_eq!(13_", stringify!($SelfT), ".wrapping_neg(), (!13) + 1);")]
|
||
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_neg(), !(42 - 1));")]
|
||
/// ```
|
||
#[stable(feature = "num_wrapping", since = "1.2.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn wrapping_neg(self) -> Self {
|
||
(0 as $SelfT).wrapping_sub(self)
|
||
}
|
||
|
||
/// Panic-free bitwise shift-left; yields `self << mask(rhs)`,
|
||
/// where `mask` removes any high-order bits of `rhs` that
|
||
/// would cause the shift to exceed the bitwidth of the type.
|
||
///
|
||
/// Note that this is *not* the same as a rotate-left; the
|
||
/// RHS of a wrapping shift-left is restricted to the range
|
||
/// of the type, rather than the bits shifted out of the LHS
|
||
/// being returned to the other end. The primitive integer
|
||
/// types all implement a [`rotate_left`](Self::rotate_left) function,
|
||
/// which may be what you want instead.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_shl(7), 128);")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_shl(128), 1);")]
|
||
/// ```
|
||
#[stable(feature = "num_wrapping", since = "1.2.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn wrapping_shl(self, rhs: u32) -> Self {
|
||
// SAFETY: the masking by the bitsize of the type ensures that we do not shift
|
||
// out of bounds
|
||
unsafe {
|
||
self.unchecked_shl(rhs & (Self::BITS - 1))
|
||
}
|
||
}
|
||
|
||
/// Panic-free bitwise shift-right; yields `self >> mask(rhs)`,
|
||
/// where `mask` removes any high-order bits of `rhs` that
|
||
/// would cause the shift to exceed the bitwidth of the type.
|
||
///
|
||
/// Note that this is *not* the same as a rotate-right; the
|
||
/// RHS of a wrapping shift-right is restricted to the range
|
||
/// of the type, rather than the bits shifted out of the LHS
|
||
/// being returned to the other end. The primitive integer
|
||
/// types all implement a [`rotate_right`](Self::rotate_right) function,
|
||
/// which may be what you want instead.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(128", stringify!($SelfT), ".wrapping_shr(7), 1);")]
|
||
#[doc = concat!("assert_eq!(128", stringify!($SelfT), ".wrapping_shr(128), 128);")]
|
||
/// ```
|
||
#[stable(feature = "num_wrapping", since = "1.2.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn wrapping_shr(self, rhs: u32) -> Self {
|
||
// SAFETY: the masking by the bitsize of the type ensures that we do not shift
|
||
// out of bounds
|
||
unsafe {
|
||
self.unchecked_shr(rhs & (Self::BITS - 1))
|
||
}
|
||
}
|
||
|
||
/// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
|
||
/// wrapping around at the boundary of the type.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(5), 243);")]
|
||
/// assert_eq!(3u8.wrapping_pow(6), 217);
|
||
/// ```
|
||
#[stable(feature = "no_panic_pow", since = "1.34.0")]
|
||
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn wrapping_pow(self, mut exp: u32) -> Self {
|
||
if exp == 0 {
|
||
return 1;
|
||
}
|
||
let mut base = self;
|
||
let mut acc: Self = 1;
|
||
|
||
if intrinsics::is_val_statically_known(exp) {
|
||
while exp > 1 {
|
||
if (exp & 1) == 1 {
|
||
acc = acc.wrapping_mul(base);
|
||
}
|
||
exp /= 2;
|
||
base = base.wrapping_mul(base);
|
||
}
|
||
|
||
// since exp!=0, finally the exp must be 1.
|
||
// Deal with the final bit of the exponent separately, since
|
||
// squaring the base afterwards is not necessary.
|
||
acc.wrapping_mul(base)
|
||
} else {
|
||
// This is faster than the above when the exponent is not known
|
||
// at compile time. We can't use the same code for the constant
|
||
// exponent case because LLVM is currently unable to unroll
|
||
// this loop.
|
||
loop {
|
||
if (exp & 1) == 1 {
|
||
acc = acc.wrapping_mul(base);
|
||
// since exp!=0, finally the exp must be 1.
|
||
if exp == 1 {
|
||
return acc;
|
||
}
|
||
}
|
||
exp /= 2;
|
||
base = base.wrapping_mul(base);
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Calculates `self` + `rhs`.
|
||
///
|
||
/// Returns a tuple of the addition along with a boolean indicating
|
||
/// whether an arithmetic overflow would occur. If an overflow would
|
||
/// have occurred then the wrapped value is returned.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (0, true));")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) {
|
||
let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT);
|
||
(a as Self, b)
|
||
}
|
||
|
||
/// Calculates `self` + `rhs` + `carry` and returns a tuple containing
|
||
/// the sum and the output carry.
|
||
///
|
||
/// Performs "ternary addition" of two integer operands and a carry-in
|
||
/// bit, and returns an output integer and a carry-out bit. This allows
|
||
/// chaining together multiple additions to create a wider addition, and
|
||
/// can be useful for bignum addition.
|
||
///
|
||
#[doc = concat!("This can be thought of as a ", stringify!($BITS), "-bit \"full adder\", in the electronics sense.")]
|
||
///
|
||
/// If the input carry is false, this method is equivalent to
|
||
/// [`overflowing_add`](Self::overflowing_add), and the output carry is
|
||
/// equal to the overflow flag. Note that although carry and overflow
|
||
/// flags are similar for unsigned integers, they are different for
|
||
/// signed integers.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
/// #![feature(bigint_helper_methods)]
|
||
///
|
||
#[doc = concat!("// 3 MAX (a = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
|
||
#[doc = concat!("// + 5 7 (b = 5 × 2^", stringify!($BITS), " + 7)")]
|
||
/// // ---------
|
||
#[doc = concat!("// 9 6 (sum = 9 × 2^", stringify!($BITS), " + 6)")]
|
||
///
|
||
#[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (3, ", stringify!($SelfT), "::MAX);")]
|
||
#[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")]
|
||
/// let carry0 = false;
|
||
///
|
||
/// let (sum0, carry1) = a0.carrying_add(b0, carry0);
|
||
/// assert_eq!(carry1, true);
|
||
/// let (sum1, carry2) = a1.carrying_add(b1, carry1);
|
||
/// assert_eq!(carry2, false);
|
||
///
|
||
/// assert_eq!((sum1, sum0), (9, 6));
|
||
/// ```
|
||
#[unstable(feature = "bigint_helper_methods", issue = "85532")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) {
|
||
// note: longer-term this should be done via an intrinsic, but this has been shown
|
||
// to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic
|
||
let (a, b) = self.overflowing_add(rhs);
|
||
let (c, d) = a.overflowing_add(carry as $SelfT);
|
||
(c, b | d)
|
||
}
|
||
|
||
/// Calculates `self` + `rhs` with a signed `rhs`.
|
||
///
|
||
/// Returns a tuple of the addition along with a boolean indicating
|
||
/// whether an arithmetic overflow would occur. If an overflow would
|
||
/// have occurred then the wrapped value is returned.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(2), (3, false));")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(-2), (", stringify!($SelfT), "::MAX, true));")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_signed(4), (1, true));")]
|
||
/// ```
|
||
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
|
||
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn overflowing_add_signed(self, rhs: $SignedT) -> (Self, bool) {
|
||
let (res, overflowed) = self.overflowing_add(rhs as Self);
|
||
(res, overflowed ^ (rhs < 0))
|
||
}
|
||
|
||
/// Calculates `self` - `rhs`.
|
||
///
|
||
/// Returns a tuple of the subtraction along with a boolean indicating
|
||
/// whether an arithmetic overflow would occur. If an overflow would
|
||
/// have occurred then the wrapped value is returned.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")]
|
||
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) {
|
||
let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT);
|
||
(a as Self, b)
|
||
}
|
||
|
||
/// Calculates `self` − `rhs` − `borrow` and returns a tuple
|
||
/// containing the difference and the output borrow.
|
||
///
|
||
/// Performs "ternary subtraction" by subtracting both an integer
|
||
/// operand and a borrow-in bit from `self`, and returns an output
|
||
/// integer and a borrow-out bit. This allows chaining together multiple
|
||
/// subtractions to create a wider subtraction, and can be useful for
|
||
/// bignum subtraction.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
/// #![feature(bigint_helper_methods)]
|
||
///
|
||
#[doc = concat!("// 9 6 (a = 9 × 2^", stringify!($BITS), " + 6)")]
|
||
#[doc = concat!("// - 5 7 (b = 5 × 2^", stringify!($BITS), " + 7)")]
|
||
/// // ---------
|
||
#[doc = concat!("// 3 MAX (diff = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
|
||
///
|
||
#[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (9, 6);")]
|
||
#[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")]
|
||
/// let borrow0 = false;
|
||
///
|
||
/// let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0);
|
||
/// assert_eq!(borrow1, true);
|
||
/// let (diff1, borrow2) = a1.borrowing_sub(b1, borrow1);
|
||
/// assert_eq!(borrow2, false);
|
||
///
|
||
#[doc = concat!("assert_eq!((diff1, diff0), (3, ", stringify!($SelfT), "::MAX));")]
|
||
/// ```
|
||
#[unstable(feature = "bigint_helper_methods", issue = "85532")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) {
|
||
// note: longer-term this should be done via an intrinsic, but this has been shown
|
||
// to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic
|
||
let (a, b) = self.overflowing_sub(rhs);
|
||
let (c, d) = a.overflowing_sub(borrow as $SelfT);
|
||
(c, b | d)
|
||
}
|
||
|
||
/// Calculates `self` - `rhs` with a signed `rhs`
|
||
///
|
||
/// Returns a tuple of the subtraction along with a boolean indicating
|
||
/// whether an arithmetic overflow would occur. If an overflow would
|
||
/// have occurred then the wrapped value is returned.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(mixed_integer_ops_unsigned_sub)]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_signed(2), (", stringify!($SelfT), "::MAX, true));")]
|
||
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_signed(-2), (3, false));")]
|
||
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_sub_signed(-4), (1, true));")]
|
||
/// ```
|
||
#[unstable(feature = "mixed_integer_ops_unsigned_sub", issue = "126043")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn overflowing_sub_signed(self, rhs: $SignedT) -> (Self, bool) {
|
||
let (res, overflow) = self.overflowing_sub(rhs as Self);
|
||
|
||
(res, overflow ^ (rhs < 0))
|
||
}
|
||
|
||
/// Computes the absolute difference between `self` and `other`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($SelfT), ");")]
|
||
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($SelfT), ");")]
|
||
/// ```
|
||
#[stable(feature = "int_abs_diff", since = "1.60.0")]
|
||
#[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn abs_diff(self, other: Self) -> Self {
|
||
if mem::size_of::<Self>() == 1 {
|
||
// Trick LLVM into generating the psadbw instruction when SSE2
|
||
// is available and this function is autovectorized for u8's.
|
||
(self as i32).wrapping_sub(other as i32).abs() as Self
|
||
} else {
|
||
if self < other {
|
||
other - self
|
||
} else {
|
||
self - other
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Calculates the multiplication of `self` and `rhs`.
|
||
///
|
||
/// Returns a tuple of the multiplication along with a boolean
|
||
/// indicating whether an arithmetic overflow would occur. If an
|
||
/// overflow would have occurred then the wrapped value is returned.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// Please note that this example is shared between integer types.
|
||
/// Which explains why `u32` is used here.
|
||
///
|
||
/// ```
|
||
/// assert_eq!(5u32.overflowing_mul(2), (10, false));
|
||
/// assert_eq!(1_000_000_000u32.overflowing_mul(10), (1410065408, true));
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) {
|
||
let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT);
|
||
(a as Self, b)
|
||
}
|
||
|
||
/// Calculates the divisor when `self` is divided by `rhs`.
|
||
///
|
||
/// Returns a tuple of the divisor along with a boolean indicating
|
||
/// whether an arithmetic overflow would occur. Note that for unsigned
|
||
/// integers overflow never occurs, so the second value is always
|
||
/// `false`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
|
||
/// ```
|
||
#[inline(always)]
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[track_caller]
|
||
pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
|
||
(self / rhs, false)
|
||
}
|
||
|
||
/// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
|
||
///
|
||
/// Returns a tuple of the divisor along with a boolean indicating
|
||
/// whether an arithmetic overflow would occur. Note that for unsigned
|
||
/// integers overflow never occurs, so the second value is always
|
||
/// `false`.
|
||
/// Since, for the positive integers, all common
|
||
/// definitions of division are equal, this
|
||
/// is exactly equal to `self.overflowing_div(rhs)`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")]
|
||
/// ```
|
||
#[inline(always)]
|
||
#[stable(feature = "euclidean_division", since = "1.38.0")]
|
||
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[track_caller]
|
||
pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) {
|
||
(self / rhs, false)
|
||
}
|
||
|
||
/// Calculates the remainder when `self` is divided by `rhs`.
|
||
///
|
||
/// Returns a tuple of the remainder after dividing along with a boolean
|
||
/// indicating whether an arithmetic overflow would occur. Note that for
|
||
/// unsigned integers overflow never occurs, so the second value is
|
||
/// always `false`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")]
|
||
/// ```
|
||
#[inline(always)]
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[track_caller]
|
||
pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
|
||
(self % rhs, false)
|
||
}
|
||
|
||
/// Calculates the remainder `self.rem_euclid(rhs)` as if by Euclidean division.
|
||
///
|
||
/// Returns a tuple of the modulo after dividing along with a boolean
|
||
/// indicating whether an arithmetic overflow would occur. Note that for
|
||
/// unsigned integers overflow never occurs, so the second value is
|
||
/// always `false`.
|
||
/// Since, for the positive integers, all common
|
||
/// definitions of division are equal, this operation
|
||
/// is exactly equal to `self.overflowing_rem(rhs)`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")]
|
||
/// ```
|
||
#[inline(always)]
|
||
#[stable(feature = "euclidean_division", since = "1.38.0")]
|
||
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[track_caller]
|
||
pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
|
||
(self % rhs, false)
|
||
}
|
||
|
||
/// Negates self in an overflowing fashion.
|
||
///
|
||
/// Returns `!self + 1` using wrapping operations to return the value
|
||
/// that represents the negation of this unsigned value. Note that for
|
||
/// positive unsigned values overflow always occurs, but negating 0 does
|
||
/// not overflow.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_neg(), (0, false));")]
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2i32 as ", stringify!($SelfT), ", true));")]
|
||
/// ```
|
||
#[inline(always)]
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
pub const fn overflowing_neg(self) -> (Self, bool) {
|
||
((!self).wrapping_add(1), self != 0)
|
||
}
|
||
|
||
/// Shifts self left by `rhs` bits.
|
||
///
|
||
/// Returns a tuple of the shifted version of self along with a boolean
|
||
/// indicating whether the shift value was larger than or equal to the
|
||
/// number of bits. If the shift value is too large, then value is
|
||
/// masked (N-1) where N is the number of bits, and this value is then
|
||
/// used to perform the shift.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(4), (0x10, false));")]
|
||
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(132), (0x10, true));")]
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shl(", stringify!($BITS_MINUS_ONE), "), (0, false));")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) {
|
||
(self.wrapping_shl(rhs), rhs >= Self::BITS)
|
||
}
|
||
|
||
/// Shifts self right by `rhs` bits.
|
||
///
|
||
/// Returns a tuple of the shifted version of self along with a boolean
|
||
/// indicating whether the shift value was larger than or equal to the
|
||
/// number of bits. If the shift value is too large, then value is
|
||
/// masked (N-1) where N is the number of bits, and this value is then
|
||
/// used to perform the shift.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
|
||
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(132), (0x1, true));")]
|
||
/// ```
|
||
#[stable(feature = "wrapping", since = "1.7.0")]
|
||
#[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
|
||
(self.wrapping_shr(rhs), rhs >= Self::BITS)
|
||
}
|
||
|
||
/// Raises self to the power of `exp`, using exponentiation by squaring.
|
||
///
|
||
/// Returns a tuple of the exponentiation along with a bool indicating
|
||
/// whether an overflow happened.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(5), (243, false));")]
|
||
/// assert_eq!(3u8.overflowing_pow(6), (217, true));
|
||
/// ```
|
||
#[stable(feature = "no_panic_pow", since = "1.34.0")]
|
||
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
|
||
if exp == 0{
|
||
return (1,false);
|
||
}
|
||
let mut base = self;
|
||
let mut acc: Self = 1;
|
||
let mut overflown = false;
|
||
// Scratch space for storing results of overflowing_mul.
|
||
let mut r;
|
||
|
||
loop {
|
||
if (exp & 1) == 1 {
|
||
r = acc.overflowing_mul(base);
|
||
// since exp!=0, finally the exp must be 1.
|
||
if exp == 1 {
|
||
r.1 |= overflown;
|
||
return r;
|
||
}
|
||
acc = r.0;
|
||
overflown |= r.1;
|
||
}
|
||
exp /= 2;
|
||
r = base.overflowing_mul(base);
|
||
base = r.0;
|
||
overflown |= r.1;
|
||
}
|
||
}
|
||
|
||
/// Raises self to the power of `exp`, using exponentiation by squaring.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".pow(5), 32);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[rustc_inherit_overflow_checks]
|
||
pub const fn pow(self, mut exp: u32) -> Self {
|
||
if exp == 0 {
|
||
return 1;
|
||
}
|
||
let mut base = self;
|
||
let mut acc = 1;
|
||
|
||
if intrinsics::is_val_statically_known(exp) {
|
||
while exp > 1 {
|
||
if (exp & 1) == 1 {
|
||
acc = acc * base;
|
||
}
|
||
exp /= 2;
|
||
base = base * base;
|
||
}
|
||
|
||
// since exp!=0, finally the exp must be 1.
|
||
// Deal with the final bit of the exponent separately, since
|
||
// squaring the base afterwards is not necessary and may cause a
|
||
// needless overflow.
|
||
acc * base
|
||
} else {
|
||
// This is faster than the above when the exponent is not known
|
||
// at compile time. We can't use the same code for the constant
|
||
// exponent case because LLVM is currently unable to unroll
|
||
// this loop.
|
||
loop {
|
||
if (exp & 1) == 1 {
|
||
acc = acc * base;
|
||
// since exp!=0, finally the exp must be 1.
|
||
if exp == 1 {
|
||
return acc;
|
||
}
|
||
}
|
||
exp /= 2;
|
||
base = base * base;
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Returns the square root of the number, rounded down.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".isqrt(), 3);")]
|
||
/// ```
|
||
#[stable(feature = "isqrt", since = "1.84.0")]
|
||
#[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn isqrt(self) -> Self {
|
||
let result = crate::num::int_sqrt::$ActualT(self as $ActualT) as $SelfT;
|
||
|
||
// Inform the optimizer what the range of outputs is. If testing
|
||
// `core` crashes with no panic message and a `num::int_sqrt::u*`
|
||
// test failed, it's because your edits caused these assertions or
|
||
// the assertions in `fn isqrt` of `nonzero.rs` to become false.
|
||
//
|
||
// SAFETY: Integer square root is a monotonically nondecreasing
|
||
// function, which means that increasing the input will never
|
||
// cause the output to decrease. Thus, since the input for unsigned
|
||
// integers is bounded by `[0, <$ActualT>::MAX]`, sqrt(n) will be
|
||
// bounded by `[sqrt(0), sqrt(<$ActualT>::MAX)]`.
|
||
unsafe {
|
||
const MAX_RESULT: $SelfT = crate::num::int_sqrt::$ActualT(<$ActualT>::MAX) as $SelfT;
|
||
crate::hint::assert_unchecked(result <= MAX_RESULT);
|
||
}
|
||
|
||
result
|
||
}
|
||
|
||
/// Performs Euclidean division.
|
||
///
|
||
/// Since, for the positive integers, all common
|
||
/// definitions of division are equal, this
|
||
/// is exactly equal to `self / rhs`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(7", stringify!($SelfT), ".div_euclid(4), 1); // or any other integer type")]
|
||
/// ```
|
||
#[stable(feature = "euclidean_division", since = "1.38.0")]
|
||
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn div_euclid(self, rhs: Self) -> Self {
|
||
self / rhs
|
||
}
|
||
|
||
|
||
/// Calculates the least remainder of `self (mod rhs)`.
|
||
///
|
||
/// Since, for the positive integers, all common
|
||
/// definitions of division are equal, this
|
||
/// is exactly equal to `self % rhs`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(7", stringify!($SelfT), ".rem_euclid(4), 3); // or any other integer type")]
|
||
/// ```
|
||
#[doc(alias = "modulo", alias = "mod")]
|
||
#[stable(feature = "euclidean_division", since = "1.38.0")]
|
||
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn rem_euclid(self, rhs: Self) -> Self {
|
||
self % rhs
|
||
}
|
||
|
||
/// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
|
||
///
|
||
/// This is the same as performing `self / rhs` for all unsigned integers.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(int_roundings)]
|
||
#[doc = concat!("assert_eq!(7_", stringify!($SelfT), ".div_floor(4), 1);")]
|
||
/// ```
|
||
#[unstable(feature = "int_roundings", issue = "88581")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline(always)]
|
||
#[track_caller]
|
||
pub const fn div_floor(self, rhs: Self) -> Self {
|
||
self / rhs
|
||
}
|
||
|
||
/// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(7_", stringify!($SelfT), ".div_ceil(4), 2);")]
|
||
/// ```
|
||
#[stable(feature = "int_roundings1", since = "1.73.0")]
|
||
#[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[track_caller]
|
||
pub const fn div_ceil(self, rhs: Self) -> Self {
|
||
let d = self / rhs;
|
||
let r = self % rhs;
|
||
if r > 0 {
|
||
d + 1
|
||
} else {
|
||
d
|
||
}
|
||
}
|
||
|
||
/// Calculates the smallest value greater than or equal to `self` that
|
||
/// is a multiple of `rhs`.
|
||
///
|
||
/// # Panics
|
||
///
|
||
/// This function will panic if `rhs` is zero.
|
||
///
|
||
/// ## Overflow behavior
|
||
///
|
||
/// On overflow, this function will panic if overflow checks are enabled (default in debug
|
||
/// mode) and wrap if overflow checks are disabled (default in release mode).
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")]
|
||
#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")]
|
||
/// ```
|
||
#[stable(feature = "int_roundings1", since = "1.73.0")]
|
||
#[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[rustc_inherit_overflow_checks]
|
||
pub const fn next_multiple_of(self, rhs: Self) -> Self {
|
||
match self % rhs {
|
||
0 => self,
|
||
r => self + (rhs - r)
|
||
}
|
||
}
|
||
|
||
/// Calculates the smallest value greater than or equal to `self` that
|
||
/// is a multiple of `rhs`. Returns `None` if `rhs` is zero or the
|
||
/// operation would result in overflow.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")]
|
||
#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")]
|
||
#[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
|
||
/// ```
|
||
#[stable(feature = "int_roundings1", since = "1.73.0")]
|
||
#[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
|
||
match try_opt!(self.checked_rem(rhs)) {
|
||
0 => Some(self),
|
||
// rhs - r cannot overflow because r is smaller than rhs
|
||
r => self.checked_add(rhs - r)
|
||
}
|
||
}
|
||
|
||
/// Returns `true` if `self` is an integer multiple of `rhs`, and false otherwise.
|
||
///
|
||
/// This function is equivalent to `self % rhs == 0`, except that it will not panic
|
||
/// for `rhs == 0`. Instead, `0.is_multiple_of(0) == true`, and for any non-zero `n`,
|
||
/// `n.is_multiple_of(0) == false`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(unsigned_is_multiple_of)]
|
||
#[doc = concat!("assert!(6_", stringify!($SelfT), ".is_multiple_of(2));")]
|
||
#[doc = concat!("assert!(!5_", stringify!($SelfT), ".is_multiple_of(2));")]
|
||
///
|
||
#[doc = concat!("assert!(0_", stringify!($SelfT), ".is_multiple_of(0));")]
|
||
#[doc = concat!("assert!(!6_", stringify!($SelfT), ".is_multiple_of(0));")]
|
||
/// ```
|
||
#[unstable(feature = "unsigned_is_multiple_of", issue = "128101")]
|
||
#[must_use]
|
||
#[inline]
|
||
#[rustc_inherit_overflow_checks]
|
||
pub const fn is_multiple_of(self, rhs: Self) -> bool {
|
||
match rhs {
|
||
0 => self == 0,
|
||
_ => self % rhs == 0,
|
||
}
|
||
}
|
||
|
||
/// Returns `true` if and only if `self == 2^k` for some `k`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert!(16", stringify!($SelfT), ".is_power_of_two());")]
|
||
#[doc = concat!("assert!(!10", stringify!($SelfT), ".is_power_of_two());")]
|
||
/// ```
|
||
#[must_use]
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_is_power_of_two", since = "1.32.0")]
|
||
#[inline(always)]
|
||
pub const fn is_power_of_two(self) -> bool {
|
||
self.count_ones() == 1
|
||
}
|
||
|
||
// Returns one less than next power of two.
|
||
// (For 8u8 next power of two is 8u8 and for 6u8 it is 8u8)
|
||
//
|
||
// 8u8.one_less_than_next_power_of_two() == 7
|
||
// 6u8.one_less_than_next_power_of_two() == 7
|
||
//
|
||
// This method cannot overflow, as in the `next_power_of_two`
|
||
// overflow cases it instead ends up returning the maximum value
|
||
// of the type, and can return 0 for 0.
|
||
#[inline]
|
||
const fn one_less_than_next_power_of_two(self) -> Self {
|
||
if self <= 1 { return 0; }
|
||
|
||
let p = self - 1;
|
||
// SAFETY: Because `p > 0`, it cannot consist entirely of leading zeros.
|
||
// That means the shift is always in-bounds, and some processors
|
||
// (such as intel pre-haswell) have more efficient ctlz
|
||
// intrinsics when the argument is non-zero.
|
||
let z = unsafe { intrinsics::ctlz_nonzero(p) };
|
||
<$SelfT>::MAX >> z
|
||
}
|
||
|
||
/// Returns the smallest power of two greater than or equal to `self`.
|
||
///
|
||
/// When return value overflows (i.e., `self > (1 << (N-1))` for type
|
||
/// `uN`), it panics in debug mode and the return value is wrapped to 0 in
|
||
/// release mode (the only situation in which this method can return 0).
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".next_power_of_two(), 2);")]
|
||
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".next_power_of_two(), 4);")]
|
||
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".next_power_of_two(), 1);")]
|
||
/// ```
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
#[rustc_inherit_overflow_checks]
|
||
pub const fn next_power_of_two(self) -> Self {
|
||
self.one_less_than_next_power_of_two() + 1
|
||
}
|
||
|
||
/// Returns the smallest power of two greater than or equal to `self`. If
|
||
/// the next power of two is greater than the type's maximum value,
|
||
/// `None` is returned, otherwise the power of two is wrapped in `Some`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_next_power_of_two(), Some(2));")]
|
||
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".checked_next_power_of_two(), Some(4));")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_power_of_two(), None);")]
|
||
/// ```
|
||
#[inline]
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
pub const fn checked_next_power_of_two(self) -> Option<Self> {
|
||
self.one_less_than_next_power_of_two().checked_add(1)
|
||
}
|
||
|
||
/// Returns the smallest power of two greater than or equal to `n`. If
|
||
/// the next power of two is greater than the type's maximum value,
|
||
/// the return value is wrapped to `0`.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// ```
|
||
/// #![feature(wrapping_next_power_of_two)]
|
||
///
|
||
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".wrapping_next_power_of_two(), 2);")]
|
||
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_next_power_of_two(), 4);")]
|
||
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_next_power_of_two(), 0);")]
|
||
/// ```
|
||
#[inline]
|
||
#[unstable(feature = "wrapping_next_power_of_two", issue = "32463",
|
||
reason = "needs decision on wrapping behavior")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
pub const fn wrapping_next_power_of_two(self) -> Self {
|
||
self.one_less_than_next_power_of_two().wrapping_add(1)
|
||
}
|
||
|
||
/// Returns the memory representation of this integer as a byte array in
|
||
/// big-endian (network) byte order.
|
||
///
|
||
#[doc = $to_xe_bytes_doc]
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")]
|
||
#[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")]
|
||
/// ```
|
||
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
|
||
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn to_be_bytes(self) -> [u8; mem::size_of::<Self>()] {
|
||
self.to_be().to_ne_bytes()
|
||
}
|
||
|
||
/// Returns the memory representation of this integer as a byte array in
|
||
/// little-endian byte order.
|
||
///
|
||
#[doc = $to_xe_bytes_doc]
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")]
|
||
#[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")]
|
||
/// ```
|
||
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
|
||
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn to_le_bytes(self) -> [u8; mem::size_of::<Self>()] {
|
||
self.to_le().to_ne_bytes()
|
||
}
|
||
|
||
/// Returns the memory representation of this integer as a byte array in
|
||
/// native byte order.
|
||
///
|
||
/// As the target platform's native endianness is used, portable code
|
||
/// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate,
|
||
/// instead.
|
||
///
|
||
#[doc = $to_xe_bytes_doc]
|
||
///
|
||
/// [`to_be_bytes`]: Self::to_be_bytes
|
||
/// [`to_le_bytes`]: Self::to_le_bytes
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")]
|
||
/// assert_eq!(
|
||
/// bytes,
|
||
/// if cfg!(target_endian = "big") {
|
||
#[doc = concat!(" ", $be_bytes)]
|
||
/// } else {
|
||
#[doc = concat!(" ", $le_bytes)]
|
||
/// }
|
||
/// );
|
||
/// ```
|
||
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
|
||
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
// SAFETY: const sound because integers are plain old datatypes so we can always
|
||
// transmute them to arrays of bytes
|
||
#[inline]
|
||
pub const fn to_ne_bytes(self) -> [u8; mem::size_of::<Self>()] {
|
||
// SAFETY: integers are plain old datatypes so we can always transmute them to
|
||
// arrays of bytes
|
||
unsafe { mem::transmute(self) }
|
||
}
|
||
|
||
/// Creates a native endian integer value from its representation
|
||
/// as a byte array in big endian.
|
||
///
|
||
#[doc = $from_xe_bytes_doc]
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
|
||
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
|
||
/// ```
|
||
///
|
||
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
|
||
#[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
|
||
/// *input = rest;
|
||
#[doc = concat!(" ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")]
|
||
/// }
|
||
/// ```
|
||
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
|
||
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
|
||
#[must_use]
|
||
#[inline]
|
||
pub const fn from_be_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
|
||
Self::from_be(Self::from_ne_bytes(bytes))
|
||
}
|
||
|
||
/// Creates a native endian integer value from its representation
|
||
/// as a byte array in little endian.
|
||
///
|
||
#[doc = $from_xe_bytes_doc]
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
|
||
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
|
||
/// ```
|
||
///
|
||
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
|
||
#[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
|
||
/// *input = rest;
|
||
#[doc = concat!(" ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")]
|
||
/// }
|
||
/// ```
|
||
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
|
||
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
|
||
#[must_use]
|
||
#[inline]
|
||
pub const fn from_le_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
|
||
Self::from_le(Self::from_ne_bytes(bytes))
|
||
}
|
||
|
||
/// Creates a native endian integer value from its memory representation
|
||
/// as a byte array in native endianness.
|
||
///
|
||
/// As the target platform's native endianness is used, portable code
|
||
/// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
|
||
/// appropriate instead.
|
||
///
|
||
/// [`from_be_bytes`]: Self::from_be_bytes
|
||
/// [`from_le_bytes`]: Self::from_le_bytes
|
||
///
|
||
#[doc = $from_xe_bytes_doc]
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```
|
||
#[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
|
||
#[doc = concat!(" ", $be_bytes, "")]
|
||
/// } else {
|
||
#[doc = concat!(" ", $le_bytes, "")]
|
||
/// });
|
||
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
|
||
/// ```
|
||
///
|
||
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
|
||
///
|
||
/// ```
|
||
#[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
|
||
#[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
|
||
/// *input = rest;
|
||
#[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
|
||
/// }
|
||
/// ```
|
||
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
|
||
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
|
||
#[must_use]
|
||
// SAFETY: const sound because integers are plain old datatypes so we can always
|
||
// transmute to them
|
||
#[inline]
|
||
pub const fn from_ne_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
|
||
// SAFETY: integers are plain old datatypes so we can always transmute to them
|
||
unsafe { mem::transmute(bytes) }
|
||
}
|
||
|
||
/// Calculates the complete product `self * rhs` without the possibility to overflow.
|
||
///
|
||
/// This returns the low-order (wrapping) bits and the high-order (overflow) bits
|
||
/// of the result as two separate values, in that order.
|
||
///
|
||
/// If you also need to add a carry to the wide result, then you want
|
||
/// [`Self::carrying_mul`] instead.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// Please note that this example is shared between integer types.
|
||
/// Which explains why `u32` is used here.
|
||
///
|
||
/// ```
|
||
/// #![feature(bigint_helper_methods)]
|
||
/// assert_eq!(5u32.widening_mul(2), (10, 0));
|
||
/// assert_eq!(1_000_000_000u32.widening_mul(10), (1410065408, 2));
|
||
/// ```
|
||
#[unstable(feature = "bigint_helper_methods", issue = "85532")]
|
||
#[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn widening_mul(self, rhs: Self) -> (Self, Self) {
|
||
Self::carrying_mul(self, rhs, 0)
|
||
}
|
||
|
||
/// Calculates the "full multiplication" `self * rhs + carry`
|
||
/// without the possibility to overflow.
|
||
///
|
||
/// This returns the low-order (wrapping) bits and the high-order (overflow) bits
|
||
/// of the result as two separate values, in that order.
|
||
///
|
||
/// Performs "long multiplication" which takes in an extra amount to add, and may return an
|
||
/// additional amount of overflow. This allows for chaining together multiple
|
||
/// multiplications to create "big integers" which represent larger values.
|
||
///
|
||
/// If you don't need the `carry`, then you can use [`Self::widening_mul`] instead.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// Basic usage:
|
||
///
|
||
/// Please note that this example is shared between integer types.
|
||
/// Which explains why `u32` is used here.
|
||
///
|
||
/// ```
|
||
/// #![feature(bigint_helper_methods)]
|
||
/// assert_eq!(5u32.carrying_mul(2, 0), (10, 0));
|
||
/// assert_eq!(5u32.carrying_mul(2, 10), (20, 0));
|
||
/// assert_eq!(1_000_000_000u32.carrying_mul(10, 0), (1410065408, 2));
|
||
/// assert_eq!(1_000_000_000u32.carrying_mul(10, 10), (1410065418, 2));
|
||
#[doc = concat!("assert_eq!(",
|
||
stringify!($SelfT), "::MAX.carrying_mul(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
|
||
"(0, ", stringify!($SelfT), "::MAX));"
|
||
)]
|
||
/// ```
|
||
///
|
||
/// This is the core operation needed for scalar multiplication when
|
||
/// implementing it for wider-than-native types.
|
||
///
|
||
/// ```
|
||
/// #![feature(bigint_helper_methods)]
|
||
/// fn scalar_mul_eq(little_endian_digits: &mut Vec<u16>, multiplicand: u16) {
|
||
/// let mut carry = 0;
|
||
/// for d in little_endian_digits.iter_mut() {
|
||
/// (*d, carry) = d.carrying_mul(multiplicand, carry);
|
||
/// }
|
||
/// if carry != 0 {
|
||
/// little_endian_digits.push(carry);
|
||
/// }
|
||
/// }
|
||
///
|
||
/// let mut v = vec![10, 20];
|
||
/// scalar_mul_eq(&mut v, 3);
|
||
/// assert_eq!(v, [30, 60]);
|
||
///
|
||
/// assert_eq!(0x87654321_u64 * 0xFEED, 0x86D3D159E38D);
|
||
/// let mut v = vec![0x4321, 0x8765];
|
||
/// scalar_mul_eq(&mut v, 0xFEED);
|
||
/// assert_eq!(v, [0xE38D, 0xD159, 0x86D3]);
|
||
/// ```
|
||
///
|
||
/// If `carry` is zero, this is similar to [`overflowing_mul`](Self::overflowing_mul),
|
||
/// except that it gives the value of the overflow instead of just whether one happened:
|
||
///
|
||
/// ```
|
||
/// #![feature(bigint_helper_methods)]
|
||
/// let r = u8::carrying_mul(7, 13, 0);
|
||
/// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(7, 13));
|
||
/// let r = u8::carrying_mul(13, 42, 0);
|
||
/// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(13, 42));
|
||
/// ```
|
||
///
|
||
/// The value of the first field in the returned tuple matches what you'd get
|
||
/// by combining the [`wrapping_mul`](Self::wrapping_mul) and
|
||
/// [`wrapping_add`](Self::wrapping_add) methods:
|
||
///
|
||
/// ```
|
||
/// #![feature(bigint_helper_methods)]
|
||
/// assert_eq!(
|
||
/// 789_u16.carrying_mul(456, 123).0,
|
||
/// 789_u16.wrapping_mul(456).wrapping_add(123),
|
||
/// );
|
||
/// ```
|
||
#[unstable(feature = "bigint_helper_methods", issue = "85532")]
|
||
#[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
|
||
#[must_use = "this returns the result of the operation, \
|
||
without modifying the original"]
|
||
#[inline]
|
||
pub const fn carrying_mul(self, rhs: Self, carry: Self) -> (Self, Self) {
|
||
intrinsics::carrying_mul_add(self, rhs, 0, carry)
|
||
}
|
||
|
||
/// New code should prefer to use
|
||
#[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")]
|
||
///
|
||
/// Returns the smallest value that can be represented by this integer type.
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_promotable]
|
||
#[inline(always)]
|
||
#[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
|
||
#[deprecated(since = "TBD", note = "replaced by the `MIN` associated constant on this type")]
|
||
#[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_min_value")]
|
||
pub const fn min_value() -> Self { Self::MIN }
|
||
|
||
/// New code should prefer to use
|
||
#[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")]
|
||
///
|
||
/// Returns the largest value that can be represented by this integer type.
|
||
#[stable(feature = "rust1", since = "1.0.0")]
|
||
#[rustc_promotable]
|
||
#[inline(always)]
|
||
#[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
|
||
#[deprecated(since = "TBD", note = "replaced by the `MAX` associated constant on this type")]
|
||
#[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_max_value")]
|
||
pub const fn max_value() -> Self { Self::MAX }
|
||
}
|
||
}
|