Auto merge of #109684 - fee1-dead-contrib:rv_const_range, r=Mark-Simulacrum
Revert #104100, Allow using `Range` as an `Iterator` in const contexts. This fixes #109632.
This commit is contained in:
commit
1c39afb375
14 changed files with 65 additions and 92 deletions
|
@ -1,5 +1,4 @@
|
|||
use crate::convert::TryFrom;
|
||||
use crate::marker::Destruct;
|
||||
use crate::mem;
|
||||
use crate::num::NonZeroUsize;
|
||||
use crate::ops::{self, Try};
|
||||
|
@ -22,8 +21,7 @@ unsafe_impl_trusted_step![char i8 i16 i32 i64 i128 isize u8 u16 u32 u64 u128 usi
|
|||
/// The *successor* operation moves towards values that compare greater.
|
||||
/// The *predecessor* operation moves towards values that compare lesser.
|
||||
#[unstable(feature = "step_trait", reason = "recently redesigned", issue = "42168")]
|
||||
#[const_trait]
|
||||
pub trait Step: ~const Clone + ~const PartialOrd + Sized {
|
||||
pub trait Step: Clone + PartialOrd + Sized {
|
||||
/// Returns the number of *successor* steps required to get from `start` to `end`.
|
||||
///
|
||||
/// Returns `None` if the number of steps would overflow `usize`
|
||||
|
@ -237,8 +235,7 @@ macro_rules! step_integer_impls {
|
|||
$(
|
||||
#[allow(unreachable_patterns)]
|
||||
#[unstable(feature = "step_trait", reason = "recently redesigned", issue = "42168")]
|
||||
#[rustc_const_unstable(feature = "const_iter", issue = "92476")]
|
||||
impl const Step for $u_narrower {
|
||||
impl Step for $u_narrower {
|
||||
step_identical_methods!();
|
||||
|
||||
#[inline]
|
||||
|
@ -270,8 +267,7 @@ macro_rules! step_integer_impls {
|
|||
|
||||
#[allow(unreachable_patterns)]
|
||||
#[unstable(feature = "step_trait", reason = "recently redesigned", issue = "42168")]
|
||||
#[rustc_const_unstable(feature = "const_iter", issue = "92476")]
|
||||
impl const Step for $i_narrower {
|
||||
impl Step for $i_narrower {
|
||||
step_identical_methods!();
|
||||
|
||||
#[inline]
|
||||
|
@ -335,8 +331,7 @@ macro_rules! step_integer_impls {
|
|||
$(
|
||||
#[allow(unreachable_patterns)]
|
||||
#[unstable(feature = "step_trait", reason = "recently redesigned", issue = "42168")]
|
||||
#[rustc_const_unstable(feature = "const_iter", issue = "92476")]
|
||||
impl const Step for $u_wider {
|
||||
impl Step for $u_wider {
|
||||
step_identical_methods!();
|
||||
|
||||
#[inline]
|
||||
|
@ -361,8 +356,7 @@ macro_rules! step_integer_impls {
|
|||
|
||||
#[allow(unreachable_patterns)]
|
||||
#[unstable(feature = "step_trait", reason = "recently redesigned", issue = "42168")]
|
||||
#[rustc_const_unstable(feature = "const_iter", issue = "92476")]
|
||||
impl const Step for $i_wider {
|
||||
impl Step for $i_wider {
|
||||
step_identical_methods!();
|
||||
|
||||
#[inline]
|
||||
|
@ -412,8 +406,7 @@ step_integer_impls! {
|
|||
}
|
||||
|
||||
#[unstable(feature = "step_trait", reason = "recently redesigned", issue = "42168")]
|
||||
#[rustc_const_unstable(feature = "const_iter", issue = "92476")]
|
||||
impl const Step for char {
|
||||
impl Step for char {
|
||||
#[inline]
|
||||
fn steps_between(&start: &char, &end: &char) -> Option<usize> {
|
||||
let start = start as u32;
|
||||
|
@ -431,7 +424,6 @@ impl const Step for char {
|
|||
}
|
||||
|
||||
#[inline]
|
||||
#[rustc_allow_const_fn_unstable(const_try)]
|
||||
fn forward_checked(start: char, count: usize) -> Option<char> {
|
||||
let start = start as u32;
|
||||
let mut res = Step::forward_checked(start, count)?;
|
||||
|
@ -448,7 +440,6 @@ impl const Step for char {
|
|||
}
|
||||
|
||||
#[inline]
|
||||
#[rustc_allow_const_fn_unstable(const_try)]
|
||||
fn backward_checked(start: char, count: usize) -> Option<char> {
|
||||
let start = start as u32;
|
||||
let mut res = Step::backward_checked(start, count)?;
|
||||
|
@ -524,7 +515,6 @@ macro_rules! range_incl_exact_iter_impl {
|
|||
}
|
||||
|
||||
/// Specialization implementations for `Range`.
|
||||
#[const_trait]
|
||||
trait RangeIteratorImpl {
|
||||
type Item;
|
||||
|
||||
|
@ -539,7 +529,7 @@ trait RangeIteratorImpl {
|
|||
fn spec_advance_back_by(&mut self, n: usize) -> Result<(), NonZeroUsize>;
|
||||
}
|
||||
|
||||
impl<A: ~const Step + ~const Destruct> const RangeIteratorImpl for ops::Range<A> {
|
||||
impl<A: Step> RangeIteratorImpl for ops::Range<A> {
|
||||
type Item = A;
|
||||
|
||||
#[inline]
|
||||
|
@ -625,7 +615,7 @@ impl<A: ~const Step + ~const Destruct> const RangeIteratorImpl for ops::Range<A>
|
|||
}
|
||||
}
|
||||
|
||||
impl<T: ~const TrustedStep + ~const Destruct> const RangeIteratorImpl for ops::Range<T> {
|
||||
impl<T: TrustedStep> RangeIteratorImpl for ops::Range<T> {
|
||||
#[inline]
|
||||
fn spec_next(&mut self) -> Option<T> {
|
||||
if self.start < self.end {
|
||||
|
@ -713,8 +703,7 @@ impl<T: ~const TrustedStep + ~const Destruct> const RangeIteratorImpl for ops::R
|
|||
}
|
||||
|
||||
#[stable(feature = "rust1", since = "1.0.0")]
|
||||
#[rustc_const_unstable(feature = "const_iter", issue = "92476")]
|
||||
impl<A: ~const Step + ~const Destruct> const Iterator for ops::Range<A> {
|
||||
impl<A: Step> Iterator for ops::Range<A> {
|
||||
type Item = A;
|
||||
|
||||
#[inline]
|
||||
|
@ -824,8 +813,7 @@ range_incl_exact_iter_impl! {
|
|||
}
|
||||
|
||||
#[stable(feature = "rust1", since = "1.0.0")]
|
||||
#[rustc_const_unstable(feature = "const_iter", issue = "92476")]
|
||||
impl<A: ~const Step + ~const Destruct> const DoubleEndedIterator for ops::Range<A> {
|
||||
impl<A: Step> DoubleEndedIterator for ops::Range<A> {
|
||||
#[inline]
|
||||
fn next_back(&mut self) -> Option<A> {
|
||||
self.spec_next_back()
|
||||
|
|
|
@ -1,4 +1,3 @@
|
|||
use crate::marker::Destruct;
|
||||
use crate::num::NonZeroUsize;
|
||||
use crate::ops::{ControlFlow, Try};
|
||||
|
||||
|
@ -39,7 +38,6 @@ use crate::ops::{ControlFlow, Try};
|
|||
/// ```
|
||||
#[stable(feature = "rust1", since = "1.0.0")]
|
||||
#[cfg_attr(not(test), rustc_diagnostic_item = "DoubleEndedIterator")]
|
||||
#[const_trait]
|
||||
pub trait DoubleEndedIterator: Iterator {
|
||||
/// Removes and returns an element from the end of the iterator.
|
||||
///
|
||||
|
@ -136,10 +134,7 @@ pub trait DoubleEndedIterator: Iterator {
|
|||
/// [`Err(k)`]: Err
|
||||
#[inline]
|
||||
#[unstable(feature = "iter_advance_by", reason = "recently added", issue = "77404")]
|
||||
fn advance_back_by(&mut self, n: usize) -> Result<(), NonZeroUsize>
|
||||
where
|
||||
Self::Item: ~const Destruct,
|
||||
{
|
||||
fn advance_back_by(&mut self, n: usize) -> Result<(), NonZeroUsize> {
|
||||
for i in 0..n {
|
||||
if self.next_back().is_none() {
|
||||
// SAFETY: `i` is always less than `n`.
|
||||
|
@ -192,7 +187,6 @@ pub trait DoubleEndedIterator: Iterator {
|
|||
/// ```
|
||||
#[inline]
|
||||
#[stable(feature = "iter_nth_back", since = "1.37.0")]
|
||||
#[rustc_do_not_const_check]
|
||||
fn nth_back(&mut self, n: usize) -> Option<Self::Item> {
|
||||
if self.advance_back_by(n).is_err() {
|
||||
return None;
|
||||
|
@ -232,7 +226,6 @@ pub trait DoubleEndedIterator: Iterator {
|
|||
/// ```
|
||||
#[inline]
|
||||
#[stable(feature = "iterator_try_fold", since = "1.27.0")]
|
||||
#[rustc_do_not_const_check]
|
||||
fn try_rfold<B, F, R>(&mut self, init: B, mut f: F) -> R
|
||||
where
|
||||
Self: Sized,
|
||||
|
@ -304,7 +297,6 @@ pub trait DoubleEndedIterator: Iterator {
|
|||
#[doc(alias = "foldr")]
|
||||
#[inline]
|
||||
#[stable(feature = "iter_rfold", since = "1.27.0")]
|
||||
#[rustc_do_not_const_check]
|
||||
fn rfold<B, F>(mut self, init: B, mut f: F) -> B
|
||||
where
|
||||
Self: Sized,
|
||||
|
@ -360,7 +352,6 @@ pub trait DoubleEndedIterator: Iterator {
|
|||
/// ```
|
||||
#[inline]
|
||||
#[stable(feature = "iter_rfind", since = "1.27.0")]
|
||||
#[rustc_do_not_const_check]
|
||||
fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item>
|
||||
where
|
||||
Self: Sized,
|
||||
|
|
|
@ -1,6 +1,5 @@
|
|||
use crate::array;
|
||||
use crate::cmp::{self, Ordering};
|
||||
use crate::marker::Destruct;
|
||||
use crate::num::NonZeroUsize;
|
||||
use crate::ops::{ChangeOutputType, ControlFlow, FromResidual, Residual, Try};
|
||||
|
||||
|
@ -340,10 +339,8 @@ pub trait Iterator {
|
|||
/// ```
|
||||
#[inline]
|
||||
#[unstable(feature = "iter_advance_by", reason = "recently added", issue = "77404")]
|
||||
fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize>
|
||||
where
|
||||
Self::Item: ~const Destruct,
|
||||
{
|
||||
#[rustc_do_not_const_check]
|
||||
fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> {
|
||||
for i in 0..n {
|
||||
if self.next().is_none() {
|
||||
// SAFETY: `i` is always less than `n`.
|
||||
|
@ -394,10 +391,8 @@ pub trait Iterator {
|
|||
/// ```
|
||||
#[inline]
|
||||
#[stable(feature = "rust1", since = "1.0.0")]
|
||||
fn nth(&mut self, n: usize) -> Option<Self::Item>
|
||||
where
|
||||
Self::Item: ~const Destruct,
|
||||
{
|
||||
#[rustc_do_not_const_check]
|
||||
fn nth(&mut self, n: usize) -> Option<Self::Item> {
|
||||
self.advance_by(n).ok()?;
|
||||
self.next()
|
||||
}
|
||||
|
|
|
@ -86,5 +86,4 @@ pub unsafe trait InPlaceIterable: Iterator {}
|
|||
/// for details. Consumers are free to rely on the invariants in unsafe code.
|
||||
#[unstable(feature = "trusted_step", issue = "85731")]
|
||||
#[rustc_specialization_trait]
|
||||
#[const_trait]
|
||||
pub unsafe trait TrustedStep: ~const Step {}
|
||||
pub unsafe trait TrustedStep: Step {}
|
||||
|
|
|
@ -123,11 +123,9 @@
|
|||
#![feature(const_index_range_slice_index)]
|
||||
#![feature(const_inherent_unchecked_arith)]
|
||||
#![feature(const_int_unchecked_arith)]
|
||||
#![feature(const_intoiterator_identity)]
|
||||
#![feature(const_intrinsic_forget)]
|
||||
#![feature(const_ipv4)]
|
||||
#![feature(const_ipv6)]
|
||||
#![feature(const_iter)]
|
||||
#![feature(const_likely)]
|
||||
#![feature(const_maybe_uninit_uninit_array)]
|
||||
#![feature(const_maybe_uninit_as_mut_ptr)]
|
||||
|
|
|
@ -1,36 +0,0 @@
|
|||
#[test]
|
||||
fn const_manual_iter() {
|
||||
struct S(bool);
|
||||
|
||||
impl const Iterator for S {
|
||||
type Item = ();
|
||||
|
||||
fn next(&mut self) -> Option<Self::Item> {
|
||||
if self.0 == false {
|
||||
self.0 = true;
|
||||
Some(())
|
||||
} else {
|
||||
None
|
||||
}
|
||||
}
|
||||
}
|
||||
const {
|
||||
let mut val = S(false);
|
||||
assert!(val.next().is_some());
|
||||
assert!(val.next().is_none());
|
||||
assert!(val.next().is_none());
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn const_range() {
|
||||
const {
|
||||
let mut arr = [0; 3];
|
||||
for i in 0..arr.len() {
|
||||
arr[i] = i;
|
||||
}
|
||||
assert!(arr[0] == 0);
|
||||
assert!(arr[1] == 1);
|
||||
assert!(arr[2] == 2);
|
||||
}
|
||||
}
|
|
@ -20,8 +20,6 @@ mod range;
|
|||
mod sources;
|
||||
mod traits;
|
||||
|
||||
mod consts;
|
||||
|
||||
use core::cell::Cell;
|
||||
use core::convert::TryFrom;
|
||||
use core::iter::*;
|
||||
|
|
|
@ -12,11 +12,8 @@
|
|||
#![feature(const_caller_location)]
|
||||
#![feature(const_cell_into_inner)]
|
||||
#![feature(const_convert)]
|
||||
#![feature(const_for)]
|
||||
#![feature(const_hash)]
|
||||
#![feature(const_heap)]
|
||||
#![feature(const_intoiterator_identity)]
|
||||
#![feature(const_iter)]
|
||||
#![feature(const_maybe_uninit_as_mut_ptr)]
|
||||
#![feature(const_maybe_uninit_assume_init_read)]
|
||||
#![feature(const_nonnull_new)]
|
||||
|
|
|
@ -7,6 +7,7 @@ const fn f(x: usize) -> usize {
|
|||
//~| ERROR `for` is not allowed in a `const fn`
|
||||
//~| ERROR mutable references are not allowed in constant functions
|
||||
//~| ERROR cannot call non-const fn
|
||||
//~| ERROR the trait bound
|
||||
sum += i;
|
||||
}
|
||||
sum
|
||||
|
|
|
@ -5,7 +5,7 @@ LL | / for i in 0..x {
|
|||
LL | |
|
||||
LL | |
|
||||
LL | |
|
||||
LL | |
|
||||
... |
|
||||
LL | | sum += i;
|
||||
LL | | }
|
||||
| |_____^
|
||||
|
@ -33,6 +33,19 @@ LL | for i in 0..x {
|
|||
= note: see issue #57349 <https://github.com/rust-lang/rust/issues/57349> for more information
|
||||
= help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
|
||||
|
||||
error[E0277]: the trait bound `std::ops::Range<usize>: Iterator` is not satisfied
|
||||
--> $DIR/const-fn-error.rs:5:14
|
||||
|
|
||||
LL | for i in 0..x {
|
||||
| ^^^^ `std::ops::Range<usize>` is not an iterator
|
||||
|
|
||||
= help: the trait `~const Iterator` is not implemented for `std::ops::Range<usize>`
|
||||
note: the trait `Iterator` is implemented for `std::ops::Range<usize>`, but that implementation is not `const`
|
||||
--> $DIR/const-fn-error.rs:5:14
|
||||
|
|
||||
LL | for i in 0..x {
|
||||
| ^^^^
|
||||
|
||||
error[E0015]: cannot call non-const fn `<std::ops::Range<usize> as Iterator>::next` in constant functions
|
||||
--> $DIR/const-fn-error.rs:5:14
|
||||
|
|
||||
|
@ -42,7 +55,7 @@ LL | for i in 0..x {
|
|||
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
|
||||
= help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
|
||||
|
||||
error: aborting due to 4 previous errors
|
||||
error: aborting due to 5 previous errors
|
||||
|
||||
Some errors have detailed explanations: E0015, E0658.
|
||||
Some errors have detailed explanations: E0015, E0277, E0658.
|
||||
For more information about an error, try `rustc --explain E0015`.
|
||||
|
|
|
@ -5,6 +5,7 @@ const _: () = {
|
|||
for _ in 0..5 {}
|
||||
//~^ error: cannot call
|
||||
//~| error: cannot convert
|
||||
//~| error: the trait bound
|
||||
};
|
||||
|
||||
fn main() {}
|
||||
|
|
|
@ -9,6 +9,19 @@ note: impl defined here, but it is not `const`
|
|||
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
|
||||
= help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
|
||||
|
||||
error[E0277]: the trait bound `std::ops::Range<i32>: Iterator` is not satisfied
|
||||
--> $DIR/const-for.rs:5:14
|
||||
|
|
||||
LL | for _ in 0..5 {}
|
||||
| ^^^^ `std::ops::Range<i32>` is not an iterator
|
||||
|
|
||||
= help: the trait `~const Iterator` is not implemented for `std::ops::Range<i32>`
|
||||
note: the trait `Iterator` is implemented for `std::ops::Range<i32>`, but that implementation is not `const`
|
||||
--> $DIR/const-for.rs:5:14
|
||||
|
|
||||
LL | for _ in 0..5 {}
|
||||
| ^^^^
|
||||
|
||||
error[E0015]: cannot call non-const fn `<std::ops::Range<i32> as Iterator>::next` in constants
|
||||
--> $DIR/const-for.rs:5:14
|
||||
|
|
||||
|
@ -18,6 +31,7 @@ LL | for _ in 0..5 {}
|
|||
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
|
||||
= help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
|
||||
|
||||
error: aborting due to 2 previous errors
|
||||
error: aborting due to 3 previous errors
|
||||
|
||||
For more information about this error, try `rustc --explain E0015`.
|
||||
Some errors have detailed explanations: E0015, E0277.
|
||||
For more information about an error, try `rustc --explain E0015`.
|
||||
|
|
|
@ -228,4 +228,5 @@ fn evens_squared(n: usize) -> _ {
|
|||
|
||||
const _: _ = (1..10).filter(|x| x % 2 == 0).map(|x| x * x);
|
||||
//~^ ERROR the trait bound
|
||||
//~| ERROR the trait bound
|
||||
//~| ERROR the placeholder
|
||||
|
|
|
@ -437,6 +437,19 @@ LL | fn evens_squared(n: usize) -> _ {
|
|||
| not allowed in type signatures
|
||||
| help: replace with an appropriate return type: `impl Iterator<Item = usize>`
|
||||
|
||||
error[E0277]: the trait bound `std::ops::Range<{integer}>: Iterator` is not satisfied
|
||||
--> $DIR/typeck_type_placeholder_item.rs:229:22
|
||||
|
|
||||
LL | const _: _ = (1..10).filter(|x| x % 2 == 0).map(|x| x * x);
|
||||
| ^^^^^^ `std::ops::Range<{integer}>` is not an iterator
|
||||
|
|
||||
= help: the trait `~const Iterator` is not implemented for `std::ops::Range<{integer}>`
|
||||
note: the trait `Iterator` is implemented for `std::ops::Range<{integer}>`, but that implementation is not `const`
|
||||
--> $DIR/typeck_type_placeholder_item.rs:229:14
|
||||
|
|
||||
LL | const _: _ = (1..10).filter(|x| x % 2 == 0).map(|x| x * x);
|
||||
| ^^^^^^^
|
||||
|
||||
error[E0277]: the trait bound `Filter<std::ops::Range<{integer}>, [closure@$DIR/typeck_type_placeholder_item.rs:229:29: 229:32]>: Iterator` is not satisfied
|
||||
--> $DIR/typeck_type_placeholder_item.rs:229:45
|
||||
|
|
||||
|
@ -664,7 +677,7 @@ LL | const D: _ = 42;
|
|||
| not allowed in type signatures
|
||||
| help: replace with the correct type: `i32`
|
||||
|
||||
error: aborting due to 72 previous errors
|
||||
error: aborting due to 73 previous errors
|
||||
|
||||
Some errors have detailed explanations: E0121, E0277, E0282, E0403.
|
||||
For more information about an error, try `rustc --explain E0121`.
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue