rollup merge of #23860: nikomatsakis/copy-requires-clone

Conflicts:
	src/test/compile-fail/coherence-impls-copy.rs

Author: alexcrichton

src/doc/reference.md

@@ -1648,7 +1648,7 @@ specific type.
 Implementations are defined with the keyword `impl`.
 
 ```
-# #[derive(Copy)]
+# #[derive(Copy, Clone)]
 # struct Point {x: f64, y: f64};
 # type Surface = i32;
 # struct BoundingBox {x: f64, y: f64, width: f64, height: f64};
@@ -1661,6 +1661,10 @@ struct Circle {
 
 impl Copy for Circle {}
 
+impl Clone for Circle {
+    fn clone(&self) -> Circle { *self }
+}
+
 impl Shape for Circle {
     fn draw(&self, s: Surface) { do_draw_circle(s, *self); }
     fn bounding_box(&self) -> BoundingBox {

src/libcollections/binary_heap.rs

@@ -30,7 +30,7 @@
 //! use std::collections::BinaryHeap;
 //! use std::usize;
 //!
-//! #[derive(Copy, Eq, PartialEq)]
+//! #[derive(Copy, Clone, Eq, PartialEq)]
 //! struct State {
 //!     cost: usize,
 //!     position: usize,

src/libcollections/btree/node.rs

@@ -526,7 +526,7 @@ impl<K: Clone, V: Clone> Clone for Node<K, V> {
 ///     println!("Uninitialized memory: {:?}", handle.into_kv());
 /// }
 /// ```
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 pub struct Handle<NodeRef, Type, NodeType> {
     node: NodeRef,
     index: usize,

src/libcollections/enum_set.rs

@@ -21,7 +21,7 @@ use core::ops::{Sub, BitOr, BitAnd, BitXor};
 
 // FIXME(contentions): implement union family of methods? (general design may be wrong here)
 
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(PartialEq, Eq, PartialOrd, Ord, Hash)]
 /// A specialized set implementation to use enum types.
 ///
 /// It is a logic error for an item to be modified in such a way that the transformation of the
@@ -37,6 +37,10 @@ pub struct EnumSet<E> {
 
 impl<E> Copy for EnumSet<E> {}
 
+impl<E> Clone for EnumSet<E> {
+    fn clone(&self) -> EnumSet<E> { *self }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<E:CLike + fmt::Debug> fmt::Debug for EnumSet<E> {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {

src/libcollectionstest/enum_set.rs

@@ -14,7 +14,7 @@ use collections::enum_set::{CLike, EnumSet};
 
 use self::Foo::*;
 
-#[derive(Copy, PartialEq, Debug)]
+#[derive(Copy, Clone, PartialEq, Debug)]
 #[repr(usize)]
 enum Foo {
     A, B, C
@@ -218,7 +218,7 @@ fn test_operators() {
 #[should_panic]
 fn test_overflow() {
     #[allow(dead_code)]
-    #[derive(Copy)]
+    #[derive(Copy, Clone)]
     #[repr(usize)]
     enum Bar {
         V00, V01, V02, V03, V04, V05, V06, V07, V08, V09,

src/libcore/atomic.rs

@@ -122,7 +122,7 @@ unsafe impl<T> Sync for AtomicPtr<T> {}
 /// Rust's memory orderings are [the same as
 /// C++'s](http://gcc.gnu.org/wiki/Atomic/GCCMM/AtomicSync).
 #[stable(feature = "rust1", since = "1.0.0")]
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 pub enum Ordering {
     /// No ordering constraints, only atomic operations.
     #[stable(feature = "rust1", since = "1.0.0")]

src/libcore/fmt/mod.rs

@@ -14,6 +14,7 @@
 
 use cell::{Cell, RefCell, Ref, RefMut, BorrowState};
 use char::CharExt;
+use clone::Clone;
 use iter::Iterator;
 use marker::{Copy, PhantomData, Sized};
 use mem;
@@ -53,7 +54,7 @@ pub type Result = result::Result<(), Error>;
 /// occurred. Any extra information must be arranged to be transmitted through
 /// some other means.
 #[stable(feature = "rust1", since = "1.0.0")]
-#[derive(Copy, Debug)]
+#[derive(Copy, Clone, Debug)]
 pub struct Error;
 
 /// A collection of methods that are required to format a message into a stream.
@@ -140,6 +141,12 @@ pub struct ArgumentV1<'a> {
     formatter: fn(&Void, &mut Formatter) -> Result,
 }
 
+impl<'a> Clone for ArgumentV1<'a> {
+    fn clone(&self) -> ArgumentV1<'a> {
+        *self
+    }
+}
+
 impl<'a> ArgumentV1<'a> {
     #[inline(never)]
     fn show_usize(x: &usize, f: &mut Formatter) -> Result {
@@ -174,7 +181,7 @@ impl<'a> ArgumentV1<'a> {
 }
 
 // flags available in the v1 format of format_args
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 #[allow(dead_code)] // SignMinus isn't currently used
 enum FlagV1 { SignPlus, SignMinus, Alternate, SignAwareZeroPad, }
 
@@ -221,7 +228,7 @@ impl<'a> Arguments<'a> {
 /// macro validates the format string at compile-time so usage of the `write`
 /// and `format` functions can be safely performed.
 #[stable(feature = "rust1", since = "1.0.0")]
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 pub struct Arguments<'a> {
     // Format string pieces to print.
     pieces: &'a [&'a str],

src/libcore/fmt/num.rs

@@ -139,7 +139,7 @@ impl GenericRadix for Radix {
 /// A helper type for formatting radixes.
 #[unstable(feature = "core",
            reason = "may be renamed or move to a different module")]
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 pub struct RadixFmt<T, R>(T, R);
 
 /// Constructs a radix formatter in the range of `2..36`.

src/libcore/fmt/rt/v1.rs

@@ -16,7 +16,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Argument {
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -25,7 +25,7 @@ pub struct Argument {
     pub format: FormatSpec,
 }
 
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct FormatSpec {
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -41,7 +41,7 @@ pub struct FormatSpec {
 }
 
 /// Possible alignments that can be requested as part of a formatting directive.
-#[derive(Copy, PartialEq)]
+#[derive(Copy, Clone, PartialEq)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub enum Alignment {
     /// Indication that contents should be left-aligned.
@@ -58,7 +58,7 @@ pub enum Alignment {
     Unknown,
 }
 
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub enum Count {
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -71,7 +71,7 @@ pub enum Count {
     Implied,
 }
 
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub enum Position {
     #[stable(feature = "rust1", since = "1.0.0")]

src/libcore/marker.rs

@@ -76,7 +76,7 @@ pub trait Sized : MarkerTrait {
 ///
 /// ```
 /// // we can just derive a `Copy` implementation
-/// #[derive(Debug, Copy)]
+/// #[derive(Debug, Copy, Clone)]
 /// struct Foo;
 ///
 /// let x = Foo;
@@ -125,7 +125,7 @@ pub trait Sized : MarkerTrait {
 /// There are two ways to implement `Copy` on your type:
 ///
 /// ```
-/// #[derive(Copy)]
+/// #[derive(Copy, Clone)]
 /// struct MyStruct;
 /// ```
 ///
@@ -134,6 +134,7 @@ pub trait Sized : MarkerTrait {
 /// ```
 /// struct MyStruct;
 /// impl Copy for MyStruct {}
+/// impl Clone for MyStruct { fn clone(&self) -> MyStruct { *self } }
 /// ```
 ///
 /// There is a small difference between the two: the `derive` strategy will also place a `Copy`
@@ -155,7 +156,7 @@ pub trait Sized : MarkerTrait {
 /// change: that second example would fail to compile if we made `Foo` non-`Copy`.
 #[stable(feature = "rust1", since = "1.0.0")]
 #[lang="copy"]
-pub trait Copy : MarkerTrait {
+pub trait Copy : Clone {
     // Empty.
 }