rollup merge of #20607: nrc/kinds

Conflicts:
	src/libcore/array.rs
	src/libcore/cell.rs
	src/libcore/prelude.rs
	src/libstd/path/posix.rs
	src/libstd/prelude/v1.rs
	src/test/compile-fail/dst-sized-trait-param.rs

src/doc/guide-unsafe.md

@@ -703,10 +703,10 @@ Other features provided by lang items include:
   `deref`, and `add` respectively.
 - stack unwinding and general failure; the `eh_personality`, `fail`
   and `fail_bounds_checks` lang items.
-- the traits in `std::kinds` used to indicate types that satisfy
+- the traits in `std::markers` used to indicate types of
   various kinds; lang items `send`, `sync` and `copy`.
 - the marker types and variance indicators found in
-  `std::kinds::markers`; lang items `covariant_type`,
+  `std::markers`; lang items `covariant_type`,
   `contravariant_lifetime`, `no_sync_bound`, etc.
 
 Lang items are loaded lazily by the compiler; e.g. if one never uses

src/liballoc/arc.rs

@@ -74,7 +74,7 @@ use core::clone::Clone;
 use core::fmt::{self, Show};
 use core::cmp::{Eq, Ord, PartialEq, PartialOrd, Ordering};
 use core::default::Default;
-use core::kinds::{Sync, Send};
+use core::marker::{Sync, Send};
 use core::mem::{min_align_of, size_of, drop};
 use core::mem;
 use core::nonzero::NonZero;

src/liballoc/boxed.rs

@@ -18,7 +18,7 @@ use core::cmp::{PartialEq, PartialOrd, Eq, Ord, Ordering};
 use core::default::Default;
 use core::fmt;
 use core::hash::{self, Hash};
-use core::kinds::Sized;
+use core::marker::Sized;
 use core::mem;
 use core::option::Option;
 use core::ptr::Unique;

src/liballoc/rc.rs

@@ -148,7 +148,7 @@ use core::cmp::{PartialEq, PartialOrd, Eq, Ord, Ordering};
 use core::default::Default;
 use core::fmt;
 use core::hash::{self, Hash};
-use core::kinds::marker;
+use core::marker;
 use core::mem::{transmute, min_align_of, size_of, forget};
 use core::nonzero::NonZero;
 use core::ops::{Deref, Drop};

src/libcollections/btree/map.rs

@@ -480,7 +480,7 @@ enum Continuation<A, B> {
 /// boilerplate gets cut out.
 mod stack {
     use core::prelude::*;
-    use core::kinds::marker;
+    use core::marker;
     use core::mem;
     use core::ops::{Deref, DerefMut};
     use super::BTreeMap;

src/libcollections/lib.rs

@@ -99,7 +99,9 @@ mod std {
     pub use core::option;   // necessary for panic!()
     pub use core::clone;    // deriving(Clone)
     pub use core::cmp;      // deriving(Eq, Ord, etc.)
-    pub use core::kinds;    // deriving(Copy)
+    #[cfg(stage0)]
+    pub use core::marker as kinds;
+    pub use core::marker;  // deriving(Copy)
     pub use core::hash;     // deriving(Hash)
 }
 
@@ -114,7 +116,7 @@ mod prelude {
     pub use core::iter::{FromIterator, Extend, IteratorExt};
     pub use core::iter::{Iterator, DoubleEndedIterator, RandomAccessIterator};
     pub use core::iter::{ExactSizeIterator};
-    pub use core::kinds::{Copy, Send, Sized, Sync};
+    pub use core::marker::{Copy, Send, Sized, Sync};
     pub use core::mem::drop;
     pub use core::ops::{Drop, Fn, FnMut, FnOnce};
     pub use core::option::Option;

src/libcollections/ring_buf.rs

@@ -20,7 +20,7 @@ use core::cmp::Ordering;
 use core::default::Default;
 use core::fmt;
 use core::iter::{self, repeat, FromIterator, RandomAccessIterator};
-use core::kinds::marker;
+use core::marker;
 use core::mem;
 use core::num::{Int, UnsignedInt};
 use core::ops::{Index, IndexMut};

src/libcollections/slice.rs

@@ -95,7 +95,7 @@ use core::cmp::Ordering::{self, Greater, Less};
 use core::cmp::{self, Ord, PartialEq};
 use core::iter::{Iterator, IteratorExt};
 use core::iter::{range, range_step, MultiplicativeIterator};
-use core::kinds::Sized;
+use core::marker::Sized;
 use core::mem::size_of;
 use core::mem;
 use core::ops::{FnMut, FullRange, Index, IndexMut};

src/libcollections/vec.rs

@@ -55,7 +55,7 @@ use core::default::Default;
 use core::fmt;
 use core::hash::{self, Hash};
 use core::iter::{repeat, FromIterator};
-use core::kinds::marker::{ContravariantLifetime, InvariantType};
+use core::marker::{ContravariantLifetime, InvariantType};
 use core::mem;
 use core::nonzero::NonZero;
 use core::num::{Int, UnsignedInt};

src/libcore/array.rs

@@ -17,7 +17,7 @@
 use clone::Clone;
 use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
 use fmt;
-use kinds::Copy;
+use marker::Copy;
 use ops::{Deref, FullRange, Index};
 use option::Option;
 

src/libcore/atomic.rs

@@ -72,7 +72,7 @@
 
 use self::Ordering::*;
 
-use kinds::Sync;
+use marker::Sync;
 
 use intrinsics;
 use cell::UnsafeCell;

src/libcore/borrow.rs

@@ -47,7 +47,7 @@
 use clone::Clone;
 use cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd};
 use fmt;
-use kinds::Sized;
+use marker::Sized;
 use ops::Deref;
 use option::Option;
 use self::Cow::*;

src/libcore/cell.rs

@@ -160,7 +160,7 @@
 use clone::Clone;
 use cmp::PartialEq;
 use default::Default;
-use kinds::{Copy, Send};
+use marker::{Copy, Send};
 use ops::{Deref, DerefMut, Drop};
 use option::Option;
 use option::Option::{None, Some};
@@ -509,7 +509,7 @@ impl<'b, T> DerefMut for RefMut<'b, T> {
 ///
 /// ```rust
 /// use std::cell::UnsafeCell;
-/// use std::kinds::marker;
+/// use std::marker;
 ///
 /// struct NotThreadSafe<T> {
 ///     value: UnsafeCell<T>,

src/libcore/clone.rs

@@ -21,7 +21,7 @@
 
 #![stable]
 
-use kinds::Sized;
+use marker::Sized;
 
 /// A common trait for cloning an object.
 #[stable]

src/libcore/cmp.rs

@@ -43,7 +43,7 @@
 
 use self::Ordering::*;
 
-use kinds::Sized;
+use marker::Sized;
 use option::Option::{self, Some, None};
 
 /// Trait for equality comparisons which are [partial equivalence relations](
@@ -316,7 +316,7 @@ pub fn partial_max<T: PartialOrd>(v1: T, v2: T) -> Option<T> {
 mod impls {
     use cmp::{PartialOrd, Ord, PartialEq, Eq, Ordering};
     use cmp::Ordering::{Less, Greater, Equal};
-    use kinds::Sized;
+    use marker::Sized;
     use option::Option;
     use option::Option::{Some, None};
 

src/libcore/fmt/mod.rs

@@ -16,7 +16,7 @@ use any;
 use cell::{Cell, RefCell, Ref, RefMut};
 use char::CharExt;
 use iter::{Iterator, IteratorExt, range};
-use kinds::{Copy, Sized};
+use marker::{Copy, Sized};
 use mem;
 use option::Option;
 use option::Option::{Some, None};

src/libcore/iter.rs

@@ -67,7 +67,7 @@ use num::{ToPrimitive, Int};
 use ops::{Add, Deref, FnMut};
 use option::Option;
 use option::Option::{Some, None};
-use std::kinds::Sized;
+use std::marker::Sized;
 use uint;
 
 /// An interface for dealing with "external iterators". These types of iterators

src/libcore/kinds.rs

@@ -1,298 +0,0 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Primitive traits representing basic 'kinds' of types
-//!
-//! Rust types can be classified in various useful ways according to
-//! intrinsic properties of the type. These classifications, often called
-//! 'kinds', are represented as traits.
-//!
-//! They cannot be implemented by user code, but are instead implemented
-//! by the compiler automatically for the types to which they apply.
-
-/// Types able to be transferred across task boundaries.
-#[lang="send"]
-pub unsafe trait Send : 'static {
-    // empty.
-}
-
-/// Types with a constant size known at compile-time.
-#[lang="sized"]
-pub trait Sized {
-    // Empty.
-}
-
-/// Types that can be copied by simply copying bits (i.e. `memcpy`).
-#[lang="copy"]
-pub trait Copy {
-    // Empty.
-}
-
-/// Types that can be safely shared between tasks when aliased.
-///
-/// The precise definition is: a type `T` is `Sync` if `&T` is
-/// thread-safe. In other words, there is no possibility of data races
-/// when passing `&T` references between tasks.
-///
-/// As one would expect, primitive types like `u8` and `f64` are all
-/// `Sync`, and so are simple aggregate types containing them (like
-/// tuples, structs and enums). More instances of basic `Sync` types
-/// include "immutable" types like `&T` and those with simple
-/// inherited mutability, such as `Box<T>`, `Vec<T>` and most other
-/// collection types. (Generic parameters need to be `Sync` for their
-/// container to be `Sync`.)
-///
-/// A somewhat surprising consequence of the definition is `&mut T` is
-/// `Sync` (if `T` is `Sync`) even though it seems that it might
-/// provide unsynchronised mutation. The trick is a mutable reference
-/// stored in an aliasable reference (that is, `& &mut T`) becomes
-/// read-only, as if it were a `& &T`, hence there is no risk of a data
-/// race.
-///
-/// Types that are not `Sync` are those that have "interior
-/// mutability" in a non-thread-safe way, such as `Cell` and `RefCell`
-/// in `std::cell`. These types allow for mutation of their contents
-/// even when in an immutable, aliasable slot, e.g. the contents of
-/// `&Cell<T>` can be `.set`, and do not ensure data races are
-/// impossible, hence they cannot be `Sync`. A higher level example
-/// of a non-`Sync` type is the reference counted pointer
-/// `std::rc::Rc`, because any reference `&Rc<T>` can clone a new
-/// reference, which modifies the reference counts in a non-atomic
-/// way.
-///
-/// For cases when one does need thread-safe interior mutability,
-/// types like the atomics in `std::sync` and `Mutex` & `RWLock` in
-/// the `sync` crate do ensure that any mutation cannot cause data
-/// races.  Hence these types are `Sync`.
-///
-/// Users writing their own types with interior mutability (or anything
-/// else that is not thread-safe) should use the `NoSync` marker type
-/// (from `std::kinds::marker`) to ensure that the compiler doesn't
-/// consider the user-defined type to be `Sync`.  Any types with
-/// interior mutability must also use the `std::cell::UnsafeCell` wrapper
-/// around the value(s) which can be mutated when behind a `&`
-/// reference; not doing this is undefined behaviour (for example,
-/// `transmute`-ing from `&T` to `&mut T` is illegal).
-#[lang="sync"]
-pub unsafe trait Sync {
-    // Empty
-}
-
-/// Marker types are special types that are used with unsafe code to
-/// inform the compiler of special constraints. Marker types should
-/// only be needed when you are creating an abstraction that is
-/// implemented using unsafe code. In that case, you may want to embed
-/// some of the marker types below into your type.
-pub mod marker {
-    use super::{Copy,Sized};
-    use clone::Clone;
-
-    /// A marker type whose type parameter `T` is considered to be
-    /// covariant with respect to the type itself. This is (typically)
-    /// used to indicate that an instance of the type `T` is being stored
-    /// into memory and read from, even though that may not be apparent.
-    ///
-    /// For more information about variance, refer to this Wikipedia
-    /// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
-    ///
-    /// *Note:* It is very unusual to have to add a covariant constraint.
-    /// If you are not sure, you probably want to use `InvariantType`.
-    ///
-    /// # Example
-    ///
-    /// Given a struct `S` that includes a type parameter `T`
-    /// but does not actually *reference* that type parameter:
-    ///
-    /// ```ignore
-    /// use std::mem;
-    ///
-    /// struct S<T> { x: *() }
-    /// fn get<T>(s: &S<T>) -> T {
-    ///    unsafe {
-    ///        let x: *T = mem::transmute(s.x);
-    ///        *x
-    ///    }
-    /// }
-    /// ```
-    ///
-    /// The type system would currently infer that the value of
-    /// the type parameter `T` is irrelevant, and hence a `S<int>` is
-    /// a subtype of `S<Box<int>>` (or, for that matter, `S<U>` for
-    /// any `U`). But this is incorrect because `get()` converts the
-    /// `*()` into a `*T` and reads from it. Therefore, we should include the
-    /// a marker field `CovariantType<T>` to inform the type checker that
-    /// `S<T>` is a subtype of `S<U>` if `T` is a subtype of `U`
-    /// (for example, `S<&'static int>` is a subtype of `S<&'a int>`
-    /// for some lifetime `'a`, but not the other way around).
-    #[lang="covariant_type"]
-    #[derive(PartialEq, Eq, PartialOrd, Ord)]
-    pub struct CovariantType<T: ?Sized>;
-
-    impl<T: ?Sized> Copy for CovariantType<T> {}
-    impl<T: ?Sized> Clone for CovariantType<T> {
-        fn clone(&self) -> CovariantType<T> { *self }
-    }
-
-    /// A marker type whose type parameter `T` is considered to be
-    /// contravariant with respect to the type itself. This is (typically)
-    /// used to indicate that an instance of the type `T` will be consumed
-    /// (but not read from), even though that may not be apparent.
-    ///
-    /// For more information about variance, refer to this Wikipedia
-    /// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
-    ///
-    /// *Note:* It is very unusual to have to add a contravariant constraint.
-    /// If you are not sure, you probably want to use `InvariantType`.
-    ///
-    /// # Example
-    ///
-    /// Given a struct `S` that includes a type parameter `T`
-    /// but does not actually *reference* that type parameter:
-    ///
-    /// ```
-    /// use std::mem;
-    ///
-    /// struct S<T> { x: *const () }
-    /// fn get<T>(s: &S<T>, v: T) {
-    ///    unsafe {
-    ///        let x: fn(T) = mem::transmute(s.x);
-    ///        x(v)
-    ///    }
-    /// }
-    /// ```
-    ///
-    /// The type system would currently infer that the value of
-    /// the type parameter `T` is irrelevant, and hence a `S<int>` is
-    /// a subtype of `S<Box<int>>` (or, for that matter, `S<U>` for
-    /// any `U`). But this is incorrect because `get()` converts the
-    /// `*()` into a `fn(T)` and then passes a value of type `T` to it.
-    ///
-    /// Supplying a `ContravariantType` marker would correct the
-    /// problem, because it would mark `S` so that `S<T>` is only a
-    /// subtype of `S<U>` if `U` is a subtype of `T`; given that the
-    /// function requires arguments of type `T`, it must also accept
-    /// arguments of type `U`, hence such a conversion is safe.
-    #[lang="contravariant_type"]
-    #[derive(PartialEq, Eq, PartialOrd, Ord)]
-    pub struct ContravariantType<T: ?Sized>;
-
-    impl<T: ?Sized> Copy for ContravariantType<T> {}
-    impl<T: ?Sized> Clone for ContravariantType<T> {
-        fn clone(&self) -> ContravariantType<T> { *self }
-    }
-
-    /// A marker type whose type parameter `T` is considered to be
-    /// invariant with respect to the type itself. This is (typically)
-    /// used to indicate that instances of the type `T` may be read or
-    /// written, even though that may not be apparent.
-    ///
-    /// For more information about variance, refer to this Wikipedia
-    /// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
-    ///
-    /// # Example
-    ///
-    /// The Cell type is an example which uses unsafe code to achieve
-    /// "interior" mutability:
-    ///
-    /// ```
-    /// pub struct Cell<T> { value: T }
-    /// # fn main() {}
-    /// ```
-    ///
-    /// The type system would infer that `value` is only read here and
-    /// never written, but in fact `Cell` uses unsafe code to achieve
-    /// interior mutability.
-    #[lang="invariant_type"]
-    #[derive(PartialEq, Eq, PartialOrd, Ord)]
-    pub struct InvariantType<T: ?Sized>;
-
-    impl<T: ?Sized> Copy for InvariantType<T> {}
-    impl<T: ?Sized> Clone for InvariantType<T> {
-        fn clone(&self) -> InvariantType<T> { *self }
-    }
-
-    /// As `CovariantType`, but for lifetime parameters. Using
-    /// `CovariantLifetime<'a>` indicates that it is ok to substitute
-    /// a *longer* lifetime for `'a` than the one you originally
-    /// started with (e.g., you could convert any lifetime `'foo` to
-    /// `'static`). You almost certainly want `ContravariantLifetime`
-    /// instead, or possibly `InvariantLifetime`. The only case where
-    /// it would be appropriate is that you have a (type-casted, and
-    /// hence hidden from the type system) function pointer with a
-    /// signature like `fn(&'a T)` (and no other uses of `'a`). In
-    /// this case, it is ok to substitute a larger lifetime for `'a`
-    /// (e.g., `fn(&'static T)`), because the function is only
-    /// becoming more selective in terms of what it accepts as
-    /// argument.
-    ///
-    /// For more information about variance, refer to this Wikipedia
-    /// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
-    #[lang="covariant_lifetime"]
-    #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-    pub struct CovariantLifetime<'a>;
-
-    /// As `ContravariantType`, but for lifetime parameters. Using
-    /// `ContravariantLifetime<'a>` indicates that it is ok to
-    /// substitute a *shorter* lifetime for `'a` than the one you
-    /// originally started with (e.g., you could convert `'static` to
-    /// any lifetime `'foo`). This is appropriate for cases where you
-    /// have an unsafe pointer that is actually a pointer into some
-    /// memory with lifetime `'a`, and thus you want to limit the
-    /// lifetime of your data structure to `'a`. An example of where
-    /// this is used is the iterator for vectors.
-    ///
-    /// For more information about variance, refer to this Wikipedia
-    /// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
-    #[lang="contravariant_lifetime"]
-    #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-    pub struct ContravariantLifetime<'a>;
-
-    /// As `InvariantType`, but for lifetime parameters. Using
-    /// `InvariantLifetime<'a>` indicates that it is not ok to
-    /// substitute any other lifetime for `'a` besides its original
-    /// value. This is appropriate for cases where you have an unsafe
-    /// pointer that is actually a pointer into memory with lifetime `'a`,
-    /// and this pointer is itself stored in an inherently mutable
-    /// location (such as a `Cell`).
-    #[lang="invariant_lifetime"]
-    #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-    pub struct InvariantLifetime<'a>;
-
-    /// A type which is considered "not sendable", meaning that it cannot
-    /// be safely sent between tasks, even if it is owned. This is
-    /// typically embedded in other types, such as `Gc`, to ensure that
-    /// their instances remain thread-local.
-    #[lang="no_send_bound"]
-    #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-    pub struct NoSend;
-
-    /// A type which is considered "not POD", meaning that it is not
-    /// implicitly copyable. This is typically embedded in other types to
-    /// ensure that they are never copied, even if they lack a destructor.
-    #[lang="no_copy_bound"]
-    #[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
-    #[allow(missing_copy_implementations)]
-    pub struct NoCopy;
-
-    /// A type which is considered "not sync", meaning that
-    /// its contents are not threadsafe, hence they cannot be
-    /// shared between tasks.
-    #[lang="no_sync_bound"]
-    #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-    pub struct NoSync;
-
-    /// A type which is considered managed by the GC. This is typically
-    /// embedded in other types.
-    #[lang="managed_bound"]
-    #[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
-    #[allow(missing_copy_implementations)]
-    pub struct Managed;
-}
-

src/libcore/lib.rs

@@ -107,7 +107,7 @@ pub mod ptr;
 
 /* Core language traits */
 
-pub mod kinds;
+pub mod marker;
 pub mod ops;
 pub mod cmp;
 pub mod clone;
@@ -146,7 +146,9 @@ mod core {
 mod std {
     pub use clone;
     pub use cmp;
-    pub use kinds;
+    #[cfg(stage0)]
+    pub use marker as kinds;
+    pub use marker;
     pub use option;
     pub use fmt;
     pub use hash;

src/libcore/marker.rs

@@ -0,0 +1,314 @@
+// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Primitive traits and marker types representing basic 'kinds' of types.
+//!
+//! Rust types can be classified in various useful ways according to
+//! intrinsic properties of the type. These classifications, often called
+//! 'kinds', are represented as traits.
+//!
+//! They cannot be implemented by user code, but are instead implemented
+//! by the compiler automatically for the types to which they apply.
+//!
+//! Marker types are special types that are used with unsafe code to
+//! inform the compiler of special constraints. Marker types should
+//! only be needed when you are creating an abstraction that is
+//! implemented using unsafe code. In that case, you may want to embed
+//! some of the marker types below into your type.
+
+#![stable]
+
+use clone::Clone;
+
+/// Types able to be transferred across task boundaries.
+#[unstable = "will be overhauled with new lifetime rules; see RFC 458"]
+#[lang="send"]
+pub unsafe trait Send: 'static {
+    // empty.
+}
+
+/// Types with a constant size known at compile-time.
+#[stable]
+#[lang="sized"]
+pub trait Sized {
+    // Empty.
+}
+
+/// Types that can be copied by simply copying bits (i.e. `memcpy`).
+#[stable]
+#[lang="copy"]
+pub trait Copy {
+    // Empty.
+}
+
+/// Types that can be safely shared between tasks when aliased.
+///
+/// The precise definition is: a type `T` is `Sync` if `&T` is
+/// thread-safe. In other words, there is no possibility of data races
+/// when passing `&T` references between tasks.
+///
+/// As one would expect, primitive types like `u8` and `f64` are all
+/// `Sync`, and so are simple aggregate types containing them (like
+/// tuples, structs and enums). More instances of basic `Sync` types
+/// include "immutable" types like `&T` and those with simple
+/// inherited mutability, such as `Box<T>`, `Vec<T>` and most other
+/// collection types. (Generic parameters need to be `Sync` for their
+/// container to be `Sync`.)
+///
+/// A somewhat surprising consequence of the definition is `&mut T` is
+/// `Sync` (if `T` is `Sync`) even though it seems that it might
+/// provide unsynchronised mutation. The trick is a mutable reference
+/// stored in an aliasable reference (that is, `& &mut T`) becomes
+/// read-only, as if it were a `& &T`, hence there is no risk of a data
+/// race.
+///
+/// Types that are not `Sync` are those that have "interior
+/// mutability" in a non-thread-safe way, such as `Cell` and `RefCell`
+/// in `std::cell`. These types allow for mutation of their contents
+/// even when in an immutable, aliasable slot, e.g. the contents of
+/// `&Cell<T>` can be `.set`, and do not ensure data races are
+/// impossible, hence they cannot be `Sync`. A higher level example
+/// of a non-`Sync` type is the reference counted pointer
+/// `std::rc::Rc`, because any reference `&Rc<T>` can clone a new
+/// reference, which modifies the reference counts in a non-atomic
+/// way.
+///
+/// For cases when one does need thread-safe interior mutability,
+/// types like the atomics in `std::sync` and `Mutex` & `RWLock` in
+/// the `sync` crate do ensure that any mutation cannot cause data
+/// races.  Hence these types are `Sync`.
+///
+/// Users writing their own types with interior mutability (or anything
+/// else that is not thread-safe) should use the `NoSync` marker type
+/// (from `std::marker`) to ensure that the compiler doesn't
+/// consider the user-defined type to be `Sync`.  Any types with
+/// interior mutability must also use the `std::cell::UnsafeCell` wrapper
+/// around the value(s) which can be mutated when behind a `&`
+/// reference; not doing this is undefined behaviour (for example,
+/// `transmute`-ing from `&T` to `&mut T` is illegal).
+#[unstable = "will be overhauled with new lifetime rules; see RFC 458"]
+#[lang="sync"]
+pub unsafe trait Sync {
+    // Empty
+}
+
+
+/// A marker type whose type parameter `T` is considered to be
+/// covariant with respect to the type itself. This is (typically)
+/// used to indicate that an instance of the type `T` is being stored
+/// into memory and read from, even though that may not be apparent.
+///
+/// For more information about variance, refer to this Wikipedia
+/// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
+///
+/// *Note:* It is very unusual to have to add a covariant constraint.
+/// If you are not sure, you probably want to use `InvariantType`.
+///
+/// # Example
+///
+/// Given a struct `S` that includes a type parameter `T`
+/// but does not actually *reference* that type parameter:
+///
+/// ```ignore
+/// use std::mem;
+///
+/// struct S<T> { x: *() }
+/// fn get<T>(s: &S<T>) -> T {
+///    unsafe {
+///        let x: *T = mem::transmute(s.x);
+///        *x
+///    }
+/// }
+/// ```
+///
+/// The type system would currently infer that the value of
+/// the type parameter `T` is irrelevant, and hence a `S<int>` is
+/// a subtype of `S<Box<int>>` (or, for that matter, `S<U>` for
+/// any `U`). But this is incorrect because `get()` converts the
+/// `*()` into a `*T` and reads from it. Therefore, we should include the
+/// a marker field `CovariantType<T>` to inform the type checker that
+/// `S<T>` is a subtype of `S<U>` if `T` is a subtype of `U`
+/// (for example, `S<&'static int>` is a subtype of `S<&'a int>`
+/// for some lifetime `'a`, but not the other way around).
+#[unstable = "likely to change with new variance strategy"]
+#[lang="covariant_type"]
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+pub struct CovariantType<T: ?Sized>;
+
+impl<T: ?Sized> Copy for CovariantType<T> {}
+impl<T: ?Sized> Clone for CovariantType<T> {
+    fn clone(&self) -> CovariantType<T> { *self }
+}
+
+/// A marker type whose type parameter `T` is considered to be
+/// contravariant with respect to the type itself. This is (typically)
+/// used to indicate that an instance of the type `T` will be consumed
+/// (but not read from), even though that may not be apparent.
+///
+/// For more information about variance, refer to this Wikipedia
+/// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
+///
+/// *Note:* It is very unusual to have to add a contravariant constraint.
+/// If you are not sure, you probably want to use `InvariantType`.
+///
+/// # Example
+///
+/// Given a struct `S` that includes a type parameter `T`
+/// but does not actually *reference* that type parameter:
+///
+/// ```
+/// use std::mem;
+///
+/// struct S<T> { x: *const () }
+/// fn get<T>(s: &S<T>, v: T) {
+///    unsafe {
+///        let x: fn(T) = mem::transmute(s.x);
+///        x(v)
+///    }
+/// }
+/// ```
+///
+/// The type system would currently infer that the value of
+/// the type parameter `T` is irrelevant, and hence a `S<int>` is
+/// a subtype of `S<Box<int>>` (or, for that matter, `S<U>` for
+/// any `U`). But this is incorrect because `get()` converts the
+/// `*()` into a `fn(T)` and then passes a value of type `T` to it.
+///
+/// Supplying a `ContravariantType` marker would correct the
+/// problem, because it would mark `S` so that `S<T>` is only a
+/// subtype of `S<U>` if `U` is a subtype of `T`; given that the
+/// function requires arguments of type `T`, it must also accept
+/// arguments of type `U`, hence such a conversion is safe.
+#[unstable = "likely to change with new variance strategy"]
+#[lang="contravariant_type"]
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+pub struct ContravariantType<T: ?Sized>;
+
+impl<T: ?Sized> Copy for ContravariantType<T> {}
+impl<T: ?Sized> Clone for ContravariantType<T> {
+    fn clone(&self) -> ContravariantType<T> { *self }
+}
+
+/// A marker type whose type parameter `T` is considered to be
+/// invariant with respect to the type itself. This is (typically)
+/// used to indicate that instances of the type `T` may be read or
+/// written, even though that may not be apparent.
+///
+/// For more information about variance, refer to this Wikipedia
+/// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
+///
+/// # Example
+///
+/// The Cell type is an example which uses unsafe code to achieve
+/// "interior" mutability:
+///
+/// ```
+/// pub struct Cell<T> { value: T }
+/// # fn main() {}
+/// ```
+///
+/// The type system would infer that `value` is only read here and
+/// never written, but in fact `Cell` uses unsafe code to achieve
+/// interior mutability.
+#[unstable = "likely to change with new variance strategy"]
+#[lang="invariant_type"]
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+pub struct InvariantType<T: ?Sized>;
+
+#[unstable = "likely to change with new variance strategy"]
+impl<T: ?Sized> Copy for InvariantType<T> {}
+#[unstable = "likely to change with new variance strategy"]
+impl<T: ?Sized> Clone for InvariantType<T> {
+    fn clone(&self) -> InvariantType<T> { *self }
+}
+
+/// As `CovariantType`, but for lifetime parameters. Using
+/// `CovariantLifetime<'a>` indicates that it is ok to substitute
+/// a *longer* lifetime for `'a` than the one you originally
+/// started with (e.g., you could convert any lifetime `'foo` to
+/// `'static`). You almost certainly want `ContravariantLifetime`
+/// instead, or possibly `InvariantLifetime`. The only case where
+/// it would be appropriate is that you have a (type-casted, and
+/// hence hidden from the type system) function pointer with a
+/// signature like `fn(&'a T)` (and no other uses of `'a`). In
+/// this case, it is ok to substitute a larger lifetime for `'a`
+/// (e.g., `fn(&'static T)`), because the function is only
+/// becoming more selective in terms of what it accepts as
+/// argument.
+///
+/// For more information about variance, refer to this Wikipedia
+/// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
+#[unstable = "likely to change with new variance strategy"]
+#[lang="covariant_lifetime"]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct CovariantLifetime<'a>;
+
+/// As `ContravariantType`, but for lifetime parameters. Using
+/// `ContravariantLifetime<'a>` indicates that it is ok to
+/// substitute a *shorter* lifetime for `'a` than the one you
+/// originally started with (e.g., you could convert `'static` to
+/// any lifetime `'foo`). This is appropriate for cases where you
+/// have an unsafe pointer that is actually a pointer into some
+/// memory with lifetime `'a`, and thus you want to limit the
+/// lifetime of your data structure to `'a`. An example of where
+/// this is used is the iterator for vectors.
+///
+/// For more information about variance, refer to this Wikipedia
+/// article <http://en.wikipedia.org/wiki/Variance_%28computer_science%29>.
+#[unstable = "likely to change with new variance strategy"]
+#[lang="contravariant_lifetime"]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct ContravariantLifetime<'a>;
+
+/// As `InvariantType`, but for lifetime parameters. Using
+/// `InvariantLifetime<'a>` indicates that it is not ok to
+/// substitute any other lifetime for `'a` besides its original
+/// value. This is appropriate for cases where you have an unsafe
+/// pointer that is actually a pointer into memory with lifetime `'a`,
+/// and this pointer is itself stored in an inherently mutable
+/// location (such as a `Cell`).
+#[unstable = "likely to change with new variance strategy"]
+#[lang="invariant_lifetime"]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct InvariantLifetime<'a>;
+
+/// A type which is considered "not sendable", meaning that it cannot
+/// be safely sent between tasks, even if it is owned. This is
+/// typically embedded in other types, such as `Gc`, to ensure that
+/// their instances remain thread-local.
+#[unstable = "likely to change with new variance strategy"]
+#[lang="no_send_bound"]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct NoSend;
+
+/// A type which is considered "not POD", meaning that it is not
+/// implicitly copyable. This is typically embedded in other types to
+/// ensure that they are never copied, even if they lack a destructor.
+#[unstable = "likely to change with new variance strategy"]
+#[lang="no_copy_bound"]
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[allow(missing_copy_implementations)]
+pub struct NoCopy;
+
+/// A type which is considered "not sync", meaning that
+/// its contents are not threadsafe, hence they cannot be
+/// shared between tasks.
+#[unstable = "likely to change with new variance strategy"]
+#[lang="no_sync_bound"]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct NoSync;
+
+/// A type which is considered managed by the GC. This is typically
+/// embedded in other types.
+#[unstable = "likely to change with new variance strategy"]
+#[lang="managed_bound"]
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[allow(missing_copy_implementations)]
+pub struct Managed;

src/libcore/mem.rs

@@ -15,7 +15,7 @@
 
 #![stable]
 
-use kinds::Sized;
+use marker::Sized;
 use intrinsics;
 use ptr;
 

src/libcore/num/mod.rs

@@ -21,7 +21,7 @@ use cmp::{PartialEq, Eq};
 use cmp::{PartialOrd, Ord};
 use intrinsics;
 use iter::IteratorExt;
-use kinds::Copy;
+use marker::Copy;
 use mem::size_of;
 use ops::{Add, Sub, Mul, Div, Rem, Neg};
 use ops::{Not, BitAnd, BitOr, BitXor, Shl, Shr, Index};
@@ -992,7 +992,7 @@ impl_to_primitive_float! { f64 }
 
 /// A generic trait for converting a number to a value.
 #[experimental = "trait is likely to be removed"]
-pub trait FromPrimitive : ::kinds::Sized {
+pub trait FromPrimitive : ::marker::Sized {
     /// Convert an `int` to return an optional value of this type. If the
     /// value cannot be represented by this value, the `None` is returned.
     #[inline]

src/libcore/ops.rs

@@ -63,7 +63,7 @@
 
 use clone::Clone;
 use iter::{Step, Iterator,DoubleEndedIterator,ExactSizeIterator};
-use kinds::Sized;
+use marker::Sized;
 use option::Option::{self, Some, None};
 
 /// The `Drop` trait is used to run some code when a value goes out of scope. This

src/libcore/prelude.rs

@@ -29,7 +29,7 @@
 //! ```
 
 // Reexported core operators
-pub use kinds::{Copy, Send, Sized, Sync};
+pub use marker::{Copy, Send, Sized, Sync};
 pub use ops::{Drop, Fn, FnMut, FnOnce, FullRange};
 
 // Reexported functions

src/libcore/ptr.rs

@@ -92,7 +92,7 @@ use mem;
 use clone::Clone;
 use intrinsics;
 use option::Option::{self, Some, None};
-use kinds::{Send, Sized, Sync};
+use marker::{Send, Sized, Sync};
 
 use cmp::{PartialEq, Eq, Ord, PartialOrd};
 use cmp::Ordering::{self, Less, Equal, Greater};

src/libcore/raw.rs

@@ -18,7 +18,7 @@
 //!
 //! Their definition should always match the ABI defined in `rustc::back::abi`.
 
-use kinds::Copy;
+use marker::Copy;
 use mem;
 
 /// The representation of a Rust slice

src/libcore/slice.rs

@@ -41,7 +41,7 @@ use cmp::Ordering::{Less, Equal, Greater};
 use cmp;
 use default::Default;
 use iter::*;
-use kinds::Copy;
+use marker::Copy;
 use num::Int;
 use ops::{FnMut, self, Index};
 use option::Option;
@@ -52,7 +52,7 @@ use ptr;
 use ptr::PtrExt;
 use mem;
 use mem::size_of;
-use kinds::{Sized, marker};
+use marker::{Sized, self};
 use raw::Repr;
 // Avoid conflicts with *both* the Slice trait (buggy) and the `slice::raw` module.
 use raw::Slice as RawSlice;

src/libcore/str/mod.rs

@@ -23,7 +23,7 @@ use default::Default;
 use iter::range;
 use iter::ExactSizeIterator;
 use iter::{Map, Iterator, IteratorExt, DoubleEndedIterator};
-use kinds::Sized;
+use marker::Sized;
 use mem;
 use num::Int;
 use ops::{Fn, FnMut, Index};

src/libcore/ty.rs

@@ -10,4 +10,4 @@
 
 //! Types dealing with unsafe actions.
 
-use kinds::marker;
+use marker;

src/libcoretest/hash/mod.rs

@@ -7,7 +7,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-use core::kinds::Sized;
+use core::marker::Sized;
 use std::mem;
 
 use core::slice::SliceExt;

src/libcoretest/num/mod.rs

@@ -12,7 +12,7 @@ use core::cmp::PartialEq;
 use core::fmt::Show;
 use core::num::{NumCast, cast};
 use core::ops::{Add, Sub, Mul, Div, Rem};
-use core::kinds::Copy;
+use core::marker::Copy;
 
 #[macro_use]
 mod int_macros;

src/libcoretest/option.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use core::option::*;
-use core::kinds::marker;
+use core::marker;
 use core::mem;
 use core::clone::Clone;
 

src/liblibc/lib.rs

@@ -5080,5 +5080,7 @@ pub fn issue_14344_workaround() {} // FIXME #14344 force linkage to happen corre
 #[doc(hidden)]
 #[cfg(not(test))]
 mod std {
-    pub use core::kinds;
+    #[cfg(stage0)]
+    pub use core::marker as kinds;
+    pub use core::marker;
 }

src/librand/lib.rs

@@ -495,7 +495,9 @@ pub struct Closed01<F>(pub F);
 mod std {
     pub use core::{option, fmt}; // panic!()
     pub use core::clone; // derive Clone
-    pub use core::kinds;
+    #[cfg(stage0)]
+    pub use core::marker as kinds;
+    pub use core::marker;
 }
 
 #[cfg(test)]

src/librustc/middle/expr_use_visitor.rs

@@ -29,7 +29,7 @@ use middle::ty::{MethodOrigin, MethodParam, MethodTypeParam};
 use middle::ty::{MethodStatic, MethodStaticUnboxedClosure};
 use util::ppaux::Repr;
 
-use std::kinds;
+use std::marker;
 use syntax::{ast, ast_util};
 use syntax::ptr::P;
 use syntax::codemap::Span;
@@ -135,7 +135,7 @@ enum TrackMatchMode<T> {
     Conflicting,
 }
 
-impl<T> kinds::Copy for TrackMatchMode<T> {}
+impl<T> marker::Copy for TrackMatchMode<T> {}
 
 impl<T> TrackMatchMode<T> {
     // Builds up the whole match mode for a pattern from its constituent

src/librustc/middle/infer/unify.rs

@@ -10,7 +10,7 @@
 
 pub use self::VarValue::*;
 
-use std::kinds::marker;
+use std::marker;
 
 use middle::ty::{expected_found, IntVarValue};
 use middle::ty::{self, Ty};

src/librustc_typeck/variance.rs

@@ -402,8 +402,8 @@ impl<'a, 'tcx, 'v> Visitor<'v> for TermsContext<'a, 'tcx> {
 struct ConstraintContext<'a, 'tcx: 'a> {
     terms_cx: TermsContext<'a, 'tcx>,
 
-    // These are the def-id of the std::kinds::marker::InvariantType,
+    // These are the def-id of the std::marker::InvariantType,
-    // std::kinds::marker::InvariantLifetime, and so on. The arrays
+    // std::marker::InvariantLifetime, and so on. The arrays
     // are indexed by the `ParamKind` (type, lifetime, self). Note
     // that there are no marker types for self, so the entries for
     // self are always None.

src/libstd/collections/hash/map.rs

@@ -21,7 +21,7 @@ use default::Default;
 use fmt::{self, Show};
 use hash::{Hash, Hasher, RandomSipHasher};
 use iter::{self, Iterator, IteratorExt, FromIterator, Extend, Map};
-use kinds::Sized;
+use marker::Sized;
 use mem::{self, replace};
 use num::{Int, UnsignedInt};
 use ops::{Deref, FnMut, Index, IndexMut};

src/libstd/collections/hash/set.rs

@@ -13,7 +13,7 @@
 use borrow::BorrowFrom;
 use clone::Clone;
 use cmp::{Eq, PartialEq};
-use core::kinds::Sized;
+use core::marker::Sized;
 use default::Default;
 use fmt::Show;
 use fmt;

src/libstd/collections/hash/table.rs

@@ -16,7 +16,7 @@ use clone::Clone;
 use cmp;
 use hash::{Hash, Hasher};
 use iter::{Iterator, count};
-use kinds::{Copy, Sized, marker};
+use marker::{Copy, Sized, self};
 use mem::{min_align_of, size_of};
 use mem;
 use num::{Int, UnsignedInt};

src/libstd/hash.rs

@@ -63,7 +63,7 @@
 
 pub use core::hash::{Hash, Hasher, Writer, hash, sip};
 
-use core::kinds::Sized;
+use core::marker::Sized;
 use default::Default;
 use rand::Rng;
 use rand;

src/libstd/io/mod.rs

@@ -232,7 +232,7 @@ use error::{FromError, Error};
 use fmt;
 use int;
 use iter::{Iterator, IteratorExt};
-use kinds::Sized;
+use marker::Sized;
 use mem::transmute;
 use ops::{FnOnce, Index};
 use option::Option;

src/libstd/io/stdio.rs

@@ -34,7 +34,7 @@ use failure::LOCAL_STDERR;
 use fmt;
 use io::{Reader, Writer, IoResult, IoError, OtherIoError, Buffer,
          standard_error, EndOfFile, LineBufferedWriter, BufferedReader};
-use kinds::{Sync, Send};
+use marker::{Sync, Send};
 use libc;
 use mem;
 use option::Option;

src/libstd/lib.rs

@@ -18,7 +18,7 @@
 //!
 //! The [`ptr`](ptr/index.html) and [`mem`](mem/index.html)
 //! modules deal with unsafe pointers and memory manipulation.
-//! [`kinds`](kinds/index.html) defines the special built-in traits,
+//! [`markers`](markers/index.html) defines the special built-in traits,
 //! and [`raw`](raw/index.html) the runtime representation of Rust types.
 //! These are some of the lowest-level building blocks in Rust.
 //!
@@ -134,7 +134,7 @@ extern crate libc;
 
 // Make std testable by not duplicating lang items. See #2912
 #[cfg(test)] extern crate "std" as realstd;
-#[cfg(test)] pub use realstd::kinds;
+#[cfg(test)] pub use realstd::marker;
 #[cfg(test)] pub use realstd::ops;
 #[cfg(test)] pub use realstd::cmp;
 #[cfg(test)] pub use realstd::boxed;
@@ -151,7 +151,8 @@ pub use core::default;
 pub use core::finally;
 pub use core::intrinsics;
 pub use core::iter;
-#[cfg(not(test))] pub use core::kinds;
+#[cfg(stage0)] #[cfg(not(test))] pub use core::marker as kinds;
+#[cfg(not(test))] pub use core::marker;
 pub use core::mem;
 #[cfg(not(test))] pub use core::ops;
 pub use core::ptr;
@@ -282,7 +283,9 @@ mod std {
     pub use vec; // used for vec![]
     pub use cell; // used for tls!
     pub use thread_local; // used for thread_local!
-    pub use kinds; // used for tls!
+    #[cfg(stage0)]
+    pub use marker as kinds;
+    pub use marker;  // used for tls!
     pub use ops; // used for bitflags!
 
     // The test runner calls ::std::os::args() but really wants realstd

src/libstd/num/mod.rs

@@ -19,7 +19,7 @@
 #[cfg(test)] use fmt::Show;
 use ops::{Add, Sub, Mul, Div, Rem, Neg};
 
-use kinds::Copy;
+use marker::Copy;
 use clone::Clone;
 use cmp::{PartialOrd, PartialEq};
 

src/libstd/os.rs

@@ -37,7 +37,7 @@ use error::{FromError, Error};
 use fmt;
 use io::{IoResult, IoError};
 use iter::{Iterator, IteratorExt};
-use kinds::Copy;
+use marker::Copy;
 use libc::{c_void, c_int, c_char};
 use libc;
 use boxed::Box;

src/libstd/path/mod.rs

@@ -61,7 +61,7 @@
 
 #![experimental]
 
-use core::kinds::Sized;
+use core::marker::Sized;
 use ffi::CString;
 use clone::Clone;
 use fmt;

src/libstd/path/posix.rs

@@ -17,8 +17,8 @@ use hash;
 use io::Writer;
 use iter::{AdditiveIterator, Extend};
 use iter::{Iterator, IteratorExt, Map};
-use prelude::v1::Index;
+use ops::Index;
-use kinds::Sized;
+use marker::Sized;
 use option::Option::{self, Some, None};
 use slice::{AsSlice, Split, SliceExt, SliceConcatExt};
 use str::{self, FromStr, StrExt};

src/libstd/prelude/v1.rs

@@ -13,9 +13,8 @@
 #![stable]
 
 // Reexported core operators
-#[stable] #[doc(no_inline)] pub use kinds::{Copy, Send, Sized, Sync};
+#[stable] #[doc(no_inline)] pub use marker::{Copy, Send, Sized, Sync};
 #[stable] #[doc(no_inline)] pub use ops::{Drop, Fn, FnMut, FnOnce, FullRange};
-#[unstable] #[doc(no_inline)] pub use ops::{Index, IndexMut};
 
 // Reexported functions
 #[stable] #[doc(no_inline)] pub use mem::drop;

src/libstd/rand/os.rs

@@ -182,7 +182,7 @@ mod imp {
     extern crate libc;
 
     use io::{IoResult};
-    use kinds::Sync;
+    use marker::Sync;
     use mem;
     use os;
     use rand::Rng;

src/libstd/rt/mod.rs

@@ -23,7 +23,7 @@
 
 #![allow(dead_code)]
 
-use kinds::Send;
+use marker::Send;
 use ops::FnOnce;
 use sys;
 use thunk::Thunk;

src/libstd/sync/mpsc/blocking.rs

@@ -13,8 +13,8 @@
 use thread::Thread;
 use sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
 use sync::Arc;
-use kinds::{Sync, Send};
+use marker::{Sync, Send};
-use kinds::marker::{NoSend, NoSync};
+use marker::{NoSend, NoSync};
 use mem;
 use clone::Clone;
 

src/libstd/sync/mpsc/mod.rs

@@ -319,7 +319,7 @@ use prelude::v1::*;
 
 use sync::Arc;
 use fmt;
-use kinds::marker;
+use marker;
 use mem;
 use cell::UnsafeCell;
 

src/libstd/sync/mpsc/select.rs

@@ -57,7 +57,7 @@
 use core::prelude::*;
 
 use core::cell::Cell;
-use core::kinds::marker;
+use core::marker;
 use core::mem;
 use core::uint;
 

src/libstd/sync/mutex.rs

@@ -11,7 +11,7 @@
 use prelude::v1::*;
 
 use cell::UnsafeCell;
-use kinds::marker;
+use marker;
 use ops::{Deref, DerefMut};
 use sync::poison::{self, TryLockError, TryLockResult, LockResult};
 use sys_common::mutex as sys;

src/libstd/sync/once.rs

@@ -14,7 +14,7 @@
 //! example use case would be for initializing an FFI library.
 
 use int;
-use kinds::Sync;
+use marker::Sync;
 use mem::drop;
 use ops::FnOnce;
 use sync::atomic::{AtomicInt, Ordering, ATOMIC_INT_INIT};

src/libstd/sync/rwlock.rs

@@ -11,7 +11,7 @@
 use prelude::v1::*;
 
 use cell::UnsafeCell;
-use kinds::marker;
+use marker;
 use ops::{Deref, DerefMut};
 use sync::poison::{self, LockResult, TryLockError, TryLockResult};
 use sys_common::rwlock as sys;

src/libstd/sys/common/mutex.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use kinds::Sync;
+use marker::Sync;
 use sys::mutex as imp;
 
 /// An OS-based mutual exclusion lock.

src/libstd/sys/unix/c.rs

@@ -165,8 +165,8 @@ mod signal {
         sa_restorer: *mut libc::c_void,
     }
 
-    unsafe impl ::kinds::Send for sigaction { }
+    unsafe impl ::marker::Send for sigaction { }
-    unsafe impl ::kinds::Sync for sigaction { }
+    unsafe impl ::marker::Sync for sigaction { }
 
     #[repr(C)]
     #[cfg(target_word_size = "32")]
@@ -217,8 +217,8 @@ mod signal {
         sa_resv: [libc::c_int; 1],
     }
 
-    unsafe impl ::kinds::Send for sigaction { }
+    unsafe impl ::marker::Send for sigaction { }
-    unsafe impl ::kinds::Sync for sigaction { }
+    unsafe impl ::marker::Sync for sigaction { }
 
     #[repr(C)]
     pub struct sigset_t {

src/libstd/sys/unix/mutex.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use cell::UnsafeCell;
-use kinds::Sync;
+use marker::Sync;
 use sys::sync as ffi;
 use sys_common::mutex;
 

src/libstd/thread.rs

@@ -128,7 +128,7 @@ use any::Any;
 use boxed::Box;
 use cell::UnsafeCell;
 use clone::Clone;
-use kinds::{Send, Sync};
+use marker::{Send, Sync};
 use ops::{Drop, FnOnce};
 use option::Option::{self, Some, None};
 use result::Result::{Err, Ok};

src/libstd/thread_local/mod.rs

@@ -345,7 +345,7 @@ mod imp {
         pub dtor_running: UnsafeCell<bool>, // should be Cell
     }
 
-    unsafe impl<T> ::kinds::Sync for Key<T> { }
+    unsafe impl<T> ::marker::Sync for Key<T> { }
 
     #[doc(hidden)]
     impl<T> Key<T> {
@@ -471,7 +471,7 @@ mod imp {
         pub os: OsStaticKey,
     }
 
-    unsafe impl<T> ::kinds::Sync for Key<T> { }
+    unsafe impl<T> ::marker::Sync for Key<T> { }
 
     struct Value<T: 'static> {
         key: &'static Key<T>,

src/libstd/thread_local/scoped.rs

@@ -108,7 +108,7 @@ macro_rules! __scoped_thread_local_inner {
         const _INIT: __Key<$t> = __Key {
             inner: ::std::thread_local::scoped::__impl::KeyInner {
                 inner: ::std::thread_local::scoped::__impl::OS_INIT,
-                marker: ::std::kinds::marker::InvariantType,
+                marker: ::std::marker::InvariantType,
             }
         };
 
@@ -211,7 +211,7 @@ mod imp {
     #[doc(hidden)]
     pub struct KeyInner<T> { pub inner: UnsafeCell<*mut T> }
 
-    unsafe impl<T> ::kinds::Sync for KeyInner<T> { }
+    unsafe impl<T> ::marker::Sync for KeyInner<T> { }
 
     #[doc(hidden)]
     impl<T> KeyInner<T> {
@@ -224,7 +224,7 @@ mod imp {
 
 #[cfg(any(windows, target_os = "android", target_os = "ios", target_arch = "aarch64"))]
 mod imp {
-    use kinds::marker;
+    use marker;
     use sys_common::thread_local::StaticKey as OsStaticKey;
 
     #[doc(hidden)]
@@ -233,7 +233,7 @@ mod imp {
         pub marker: marker::InvariantType<T>,
     }
 
-    unsafe impl<T> ::kinds::Sync for KeyInner<T> { }
+    unsafe impl<T> ::marker::Sync for KeyInner<T> { }
 
     #[doc(hidden)]
     impl<T> KeyInner<T> {

src/libstd/thunk.rs

@@ -12,7 +12,7 @@
 #![allow(missing_docs)]
 
 use alloc::boxed::Box;
-use core::kinds::Send;
+use core::marker::Send;
 use core::ops::FnOnce;
 
 pub struct Thunk<A=(),R=()> {

src/libsyntax/ext/deriving/bounds.rs

@@ -48,7 +48,7 @@ pub fn expand_deriving_bound<F>(cx: &mut ExtCtxt,
     let trait_def = TraitDef {
         span: span,
         attributes: Vec::new(),
-        path: Path::new(vec!("std", "kinds", name)),
+        path: Path::new(vec!("std", "marker", name)),
         additional_bounds: Vec::new(),
         generics: LifetimeBounds::empty(),
         methods: vec!()

src/libunicode/tables.rs

@@ -7801,7 +7801,7 @@ pub mod charwidth {
 }
 
 pub mod grapheme {
-    use core::kinds::Copy;
+    use core::marker::Copy;
     use core::slice::SliceExt;
     pub use self::GraphemeCat::*;
     use core::result::Result::{Ok, Err};

src/test/compile-fail/associated-types-unsized.rs

@@ -14,7 +14,7 @@ trait Get {
 }
 
 fn foo<T:Get>(t: T) {
-    let x = t.get(); //~ ERROR the trait `core::kinds::Sized` is not implemented
+    let x = t.get(); //~ ERROR the trait `core::marker::Sized` is not implemented
 }
 
 fn main() {

src/test/compile-fail/bad-method-typaram-kind.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 fn foo<T:'static>() {
-    1u.bar::<T>(); //~ ERROR `core::kinds::Send` is not implemented
+    1u.bar::<T>(); //~ ERROR `core::marker::Send` is not implemented
 }
 
 trait bar {

src/test/compile-fail/bad-sized.rs

@@ -16,8 +16,8 @@ trait Trait {}
 
 pub fn main() {
     let x: Vec<Trait + Sized> = Vec::new();
-    //~^ ERROR the trait `core::kinds::Sized` is not implemented
+    //~^ ERROR the trait `core::marker::Sized` is not implemented
-    //~^^ ERROR the trait `core::kinds::Sized` is not implemented
+    //~^^ ERROR the trait `core::marker::Sized` is not implemented
     let x: Vec<Box<RefCell<Trait + Sized>>> = Vec::new();
-    //~^ ERROR the trait `core::kinds::Sized` is not implemented
+    //~^ ERROR the trait `core::marker::Sized` is not implemented
 }

src/test/compile-fail/borrowck-move-out-of-static-item.rs

@@ -10,7 +10,7 @@
 
 // Ensure that moves out of static items is forbidden
 
-use std::kinds::marker;
+use std::marker;
 
 struct Foo {
     foo: int,

src/test/compile-fail/borrowck-struct-update-with-dtor.rs

@@ -12,7 +12,7 @@
 // move, when the struct implements Drop.
 
 // NoCopy
-use std::kinds::marker::NoCopy as NP;
+use std::marker::NoCopy as NP;
 
 
 struct S { a: int, np: NP }

src/test/compile-fail/builtin-superkinds-double-superkind.rs

@@ -13,9 +13,9 @@
 
 trait Foo : Send+Sync { }
 
-impl <T: Sync+'static> Foo for (T,) { } //~ ERROR the trait `core::kinds::Send` is not implemented
+impl <T: Sync+'static> Foo for (T,) { } //~ ERROR the trait `core::marker::Send` is not implemented
 
-impl <T: Send> Foo for (T,T) { } //~ ERROR the trait `core::kinds::Sync` is not implemented
+impl <T: Send> Foo for (T,T) { } //~ ERROR the trait `core::marker::Sync` is not implemented
 
 impl <T: Send+Sync> Foo for (T,T,T) { } // (ok)
 

src/test/compile-fail/builtin-superkinds-in-metadata.rs

@@ -22,6 +22,6 @@ struct X<T>(T);
 impl <T:Sync> RequiresShare for X<T> { }
 
 impl <T:Sync+'static> RequiresRequiresShareAndSend for X<T> { }
-//~^ ERROR the trait `core::kinds::Send` is not implemented
+//~^ ERROR the trait `core::marker::Send` is not implemented
 
 fn main() { }

src/test/compile-fail/builtin-superkinds-typaram-not-send.rs

@@ -12,6 +12,6 @@
 
 trait Foo : Send { }
 
-impl <T: Sync+'static> Foo for T { } //~ ERROR the trait `core::kinds::Send` is not implemented
+impl <T: Sync+'static> Foo for T { } //~ ERROR the trait `core::marker::Send` is not implemented
 
 fn main() { }

src/test/compile-fail/check-static-values-constraints.rs

@@ -10,7 +10,7 @@
 
 // Verifies all possible restrictions for statics values.
 
-use std::kinds::marker;
+use std::marker;
 
 struct WithDtor;
 

src/test/compile-fail/closure-bounds-cant-promote-superkind-in-struct.rs

@@ -13,7 +13,7 @@ struct X<F> where F: FnOnce() + 'static + Send {
 }
 
 fn foo<F>(blk: F) -> X<F> where F: FnOnce() + 'static {
-    //~^ ERROR the trait `core::kinds::Send` is not implemented for the type
+    //~^ ERROR the trait `core::marker::Send` is not implemented for the type
     return X { field: blk };
 }
 

src/test/compile-fail/closure-bounds-subtype.rs

@@ -21,7 +21,7 @@ fn give_any<F>(f: F) where F: FnOnce() {
 
 fn give_owned<F>(f: F) where F: FnOnce() + Send {
     take_any(f);
-    take_const_owned(f); //~ ERROR the trait `core::kinds::Sync` is not implemented for the type
+    take_const_owned(f); //~ ERROR the trait `core::marker::Sync` is not implemented for the type
 }
 
 fn main() {}

src/test/compile-fail/comm-not-freeze-receiver.rs

@@ -13,5 +13,5 @@ use std::sync::mpsc::Receiver;
 fn test<T: Sync>() {}
 
 fn main() {
-    test::<Receiver<int>>();   //~ ERROR: `core::kinds::Sync` is not implemented
+    test::<Receiver<int>>();   //~ ERROR: `core::marker::Sync` is not implemented
 }

src/test/compile-fail/comm-not-freeze.rs

@@ -13,5 +13,5 @@ use std::sync::mpsc::Sender;
 fn test<T: Sync>() {}
 
 fn main() {
-    test::<Sender<int>>();     //~ ERROR: `core::kinds::Sync` is not implemented
+    test::<Sender<int>>();     //~ ERROR: `core::marker::Sync` is not implemented
 }

src/test/compile-fail/dst-bad-assign-2.rs

@@ -43,5 +43,5 @@ pub fn main() {
     let f5: &mut Fat<ToBar> = &mut Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} };
     let z: Box<ToBar> = box Bar1 {f: 36};
     f5.ptr = *z;
-    //~^ ERROR the trait `core::kinds::Sized` is not implemented
+    //~^ ERROR the trait `core::marker::Sized` is not implemented
 }

src/test/compile-fail/dst-bad-assign.rs

@@ -43,5 +43,5 @@ pub fn main() {
     let f5: &mut Fat<ToBar> = &mut Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} };
     let z: Box<ToBar> = box Bar1 {f: 36};
     f5.ptr = Bar1 {f: 36}; //~ ERROR mismatched types: expected `ToBar`, found `Bar1`
-    //~^ ERROR the trait `core::kinds::Sized` is not implemented for the type `ToBar`
+    //~^ ERROR the trait `core::marker::Sized` is not implemented for the type `ToBar`
 }

src/test/compile-fail/dst-bad-deep.rs

@@ -21,5 +21,5 @@ pub fn main() {
     let f: Fat<[int; 3]> = Fat { ptr: [5i, 6, 7] };
     let g: &Fat<[int]> = &f;
     let h: &Fat<Fat<[int]>> = &Fat { ptr: *g };
-    //~^ ERROR the trait `core::kinds::Sized` is not implemented
+    //~^ ERROR the trait `core::marker::Sized` is not implemented
 }

src/test/compile-fail/dst-object-from-unsized-type.rs

@@ -15,22 +15,22 @@ impl Foo for str {}
 
 fn test1<T: ?Sized + Foo>(t: &T) {
     let u: &Foo = t;
-    //~^ ERROR `core::kinds::Sized` is not implemented for the type `T`
+    //~^ ERROR `core::marker::Sized` is not implemented for the type `T`
 }
 
 fn test2<T: ?Sized + Foo>(t: &T) {
     let v: &Foo = t as &Foo;
-    //~^ ERROR `core::kinds::Sized` is not implemented for the type `T`
+    //~^ ERROR `core::marker::Sized` is not implemented for the type `T`
 }
 
 fn test3() {
     let _: &[&Foo] = &["hi"];
-    //~^ ERROR `core::kinds::Sized` is not implemented for the type `str`
+    //~^ ERROR `core::marker::Sized` is not implemented for the type `str`
 }
 
 fn test4() {
     let _: &Foo = "hi" as &Foo;
-    //~^ ERROR `core::kinds::Sized` is not implemented for the type `str`
+    //~^ ERROR `core::marker::Sized` is not implemented for the type `str`
 }
 
 fn main() { }

src/test/compile-fail/dst-sized-trait-param.rs

@@ -14,10 +14,10 @@
 
 trait Foo<T> : Sized { fn take(self, x: &T) { } } // Note: T is sized
 
-impl Foo<[isize]> for uint { }
+impl Foo<[isize]> for usize { }
-//~^ ERROR the trait `core::kinds::Sized` is not implemented for the type `[isize]`
+//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `[isize]`
 
 impl Foo<isize> for [usize] { }
-//~^ ERROR the trait `core::kinds::Sized` is not implemented for the type `[usize]`
+//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `[usize]`
 
 pub fn main() { }

src/test/compile-fail/error-should-say-copy-not-pod.rs

@@ -13,5 +13,5 @@
 fn check_bound<T:Copy>(_: T) {}
 
 fn main() {
-    check_bound("nocopy".to_string()); //~ ERROR the trait `core::kinds::Copy` is not implemented
+    check_bound("nocopy".to_string()); //~ ERROR the trait `core::marker::Copy` is not implemented
 }

src/test/compile-fail/issue-14366.rs

@@ -10,5 +10,5 @@
 
 fn main() {
     let _x = "test" as &::std::any::Any;
-//~^ ERROR the trait `core::kinds::Sized` is not implemented for the type `str`
+//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `str`
 }

src/test/compile-fail/issue-15756.rs

@@ -15,7 +15,7 @@ fn dft_iter<'a, T>(arg1: Chunks<'a,T>, arg2: ChunksMut<'a,T>)
 {
     for
     &something
-//~^ ERROR the trait `core::kinds::Sized` is not implemented for the type `[T]`
+//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `[T]`
     in arg2
     {
     }

src/test/compile-fail/issue-16538.rs

@@ -20,6 +20,6 @@ mod Y {
 
 static foo: *const Y::X = Y::foo(Y::x as *const Y::X);
 //~^ ERROR cannot refer to other statics by value
-//~| ERROR: the trait `core::kinds::Sync` is not implemented for the type
+//~| ERROR: the trait `core::marker::Sync` is not implemented for the type
 
 fn main() {}

src/test/compile-fail/issue-17718-static-move.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::kinds::marker;
+use std::marker;
 
 struct Foo { nc: marker::NoCopy }
 const INIT: Foo = Foo { nc: marker::NoCopy };

src/test/compile-fail/issue-17718-static-sync.rs

@@ -8,12 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::kinds::marker;
+use std::marker;
 
 struct Foo { marker: marker::NoSync }
 
 static FOO: uint = 3;
 static BAR: Foo = Foo { marker: marker::NoSync };
-//~^ ERROR: the trait `core::kinds::Sync` is not implemented
+//~^ ERROR: the trait `core::marker::Sync` is not implemented
 
 fn main() {}

src/test/compile-fail/issue-18107.rs

@@ -14,7 +14,7 @@ pub trait AbstractRenderer {}
 
 fn _create_render(_: &()) ->
     AbstractRenderer
-//~^ ERROR: the trait `core::kinds::Sized` is not implemented
+//~^ ERROR: the trait `core::marker::Sized` is not implemented
 {
     match 0u {
         _ => unimplemented!()

src/test/compile-fail/issue-19883.rs

@@ -18,13 +18,13 @@ trait To {
     // This is a typo, the return type should be `<Dst as From<Self>>::Output`
     fn to<Dst: From<Self>>(
         self
-        //~^ error: the trait `core::kinds::Sized` is not implemented
+        //~^ error: the trait `core::marker::Sized` is not implemented
     ) ->
         <Dst as From<Self>>::Dst
-        //~^ error: the trait `core::kinds::Sized` is not implemented
+        //~^ error: the trait `core::marker::Sized` is not implemented
     {
         From::from(
-            //~^ error: the trait `core::kinds::Sized` is not implemented
+            //~^ error: the trait `core::marker::Sized` is not implemented
             self
         )
     }

src/test/compile-fail/issue-20005.rs

@@ -16,9 +16,9 @@ trait From<Src> {
 
 trait To {
     fn to<Dst>(
-        self //~ error: the trait `core::kinds::Sized` is not implemented
+        self //~ error: the trait `core::marker::Sized` is not implemented
     ) -> <Dst as From<Self>>::Result where Dst: From<Self> {
-        From::from( //~ error: the trait `core::kinds::Sized` is not implemented
+        From::from( //~ error: the trait `core::marker::Sized` is not implemented
             self
         )
     }

src/test/compile-fail/issue-3907-2.rs

@@ -17,6 +17,6 @@ struct S {
     name: int
 }
 
-fn bar(_x: Foo) {} //~ ERROR the trait `core::kinds::Sized` is not implemented
+fn bar(_x: Foo) {} //~ ERROR the trait `core::marker::Sized` is not implemented
 
 fn main() {}

src/test/compile-fail/issue-5035-2.rs

@@ -11,6 +11,6 @@
 trait I {}
 type K = I+'static;
 
-fn foo(_x: K) {} //~ ERROR: the trait `core::kinds::Sized` is not implemented
+fn foo(_x: K) {} //~ ERROR: the trait `core::marker::Sized` is not implemented
 
 fn main() {}

src/test/compile-fail/issue-5543.rs

@@ -14,5 +14,5 @@ impl Foo for u8 {}
 fn main() {
     let r: Box<Foo> = box 5;
     let _m: Box<Foo> = r as Box<Foo>;
-    //~^ ERROR `core::kinds::Sized` is not implemented for the type `Foo`
+    //~^ ERROR `core::marker::Sized` is not implemented for the type `Foo`
 }

src/test/compile-fail/issue-5883.rs

@@ -15,8 +15,8 @@ struct Struct {
 }
 
 fn new_struct(r: A+'static)
-    -> Struct { //~^  ERROR the trait `core::kinds::Sized` is not implemented
+    -> Struct { //~^  ERROR the trait `core::marker::Sized` is not implemented
-    //~^ ERROR the trait `core::kinds::Sized` is not implemented
+    //~^ ERROR the trait `core::marker::Sized` is not implemented
     Struct { r: r }
 }
 

src/test/compile-fail/issue-7013.rs

@@ -32,6 +32,6 @@ struct A {
 
 fn main() {
     let a = A {v: box B{v: None} as Box<Foo+Send>};
-    //~^ ERROR the trait `core::kinds::Send` is not implemented
+    //~^ ERROR the trait `core::marker::Send` is not implemented
-    //~^^ ERROR the trait `core::kinds::Send` is not implemented
+    //~^^ ERROR the trait `core::marker::Send` is not implemented
 }

src/test/compile-fail/issue-7364.rs

@@ -14,7 +14,7 @@ use std::cell::RefCell;
 // Regresion test for issue 7364
 static boxed: Box<RefCell<int>> = box RefCell::new(0);
 //~^ ERROR statics are not allowed to have custom pointers
-//~| ERROR: the trait `core::kinds::Sync` is not implemented for the type
+//~| ERROR: the trait `core::marker::Sync` is not implemented for the type
-//~| ERROR: the trait `core::kinds::Sync` is not implemented for the type
+//~| ERROR: the trait `core::marker::Sync` is not implemented for the type
 
 fn main() { }

src/test/compile-fail/kindck-copy.rs

@@ -36,14 +36,14 @@ fn test<'a,T,U:Copy>(_: &'a int) {
     assert_copy::<&'a [int]>();
 
     // ...unless they are mutable
-    assert_copy::<&'static mut int>(); //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<&'static mut int>(); //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<&'a mut int>();  //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<&'a mut int>();  //~ ERROR `core::marker::Copy` is not implemented
 
     // ~ pointers are not ok
-    assert_copy::<Box<int>>();   //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<Box<int>>();   //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<String>();   //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<String>();   //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<Vec<int> >(); //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<Vec<int> >(); //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<Box<&'a mut int>>(); //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<Box<&'a mut int>>(); //~ ERROR `core::marker::Copy` is not implemented
 
     // borrowed object types are generally ok
     assert_copy::<&'a Dummy>();
@@ -51,11 +51,11 @@ fn test<'a,T,U:Copy>(_: &'a int) {
     assert_copy::<&'static (Dummy+Copy)>();
 
     // owned object types are not ok
-    assert_copy::<Box<Dummy>>(); //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<Box<Dummy>>(); //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<Box<Dummy+Copy>>(); //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<Box<Dummy+Copy>>(); //~ ERROR `core::marker::Copy` is not implemented
 
     // mutable object types are not ok
-    assert_copy::<&'a mut (Dummy+Copy)>();  //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<&'a mut (Dummy+Copy)>();  //~ ERROR `core::marker::Copy` is not implemented
 
     // unsafe ptrs are ok
     assert_copy::<*const int>();
@@ -73,10 +73,10 @@ fn test<'a,T,U:Copy>(_: &'a int) {
     assert_copy::<MyStruct>();
 
     // structs containing non-POD are not ok
-    assert_copy::<MyNoncopyStruct>(); //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<MyNoncopyStruct>(); //~ ERROR `core::marker::Copy` is not implemented
 
     // ref counted types are not ok
-    assert_copy::<Rc<int>>();   //~ ERROR `core::kinds::Copy` is not implemented
+    assert_copy::<Rc<int>>();   //~ ERROR `core::marker::Copy` is not implemented
 }
 
 pub fn main() {