---

yaml
---
r: 236560
b: refs/heads/tmp
c: d2e2ec1
h: refs/heads/master
v: v3

Author: steveklabnik

[refs]

@@ -25,7 +25,7 @@ refs/tags/0.11.0: e1247cb1d0d681be034adb4b558b5a0c0d5720f9
 refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
 refs/heads/beta: d2e13e822a73e0ea46ae9e21afdd3155fc997f6d
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
-refs/heads/tmp: 081278eb7acc761f583351e846ebad21c88331ff
+refs/heads/tmp: d2e2ec166182e039fa7dd26581fc9e762288d440
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f
 refs/tags/homu-tmp: f859507de8c410b648d934d8f5ec1c52daac971d
 refs/tags/1.0.0-beta: 8cbb92b53468ee2b0c2d3eeb8567005953d40828

branches/tmp/src/doc/grammar.md

@@ -9,7 +9,7 @@ provides only one kind of material:
 
 This document does not serve as an introduction to the language. Background
 familiarity with the language is assumed. A separate [guide] is available to
-help acquire such background familiarity.
+help acquire such background.
 
 This document also does not serve as a reference to the [standard] library
 included in the language distribution. Those libraries are documented

branches/tmp/src/doc/reference.md

@@ -674,7 +674,7 @@ There are several kinds of item:
 * [modules](#modules)
 * [functions](#functions)
 * [type definitions](grammar.html#type-definitions)
-* [structures](#structures)
+* [structs](#structs)
 * [enumerations](#enumerations)
 * [constant items](#constant-items)
 * [static items](#static-items)
@@ -900,9 +900,10 @@ fn main() {}
 
 ### Functions
 
-A _function item_ defines a sequence of [statements](#statements) and an
-optional final [expression](#expressions), along with a name and a set of
-parameters. Functions are declared with the keyword `fn`. Functions declare a
+A _function item_ defines a sequence of [statements](#statements) and a
+final [expression](#expressions), along with a name and a set of
+parameters. Other than a name, all these are optional.
+Functions are declared with the keyword `fn`. Functions may declare a
 set of *input* [*variables*](#variables) as parameters, through which the caller
 passes arguments into the function, and the *output* [*type*](#types)
 of the value the function will return to its caller on completion.
@@ -921,7 +922,7 @@ An example of a function:
 
 ```
 fn add(x: i32, y: i32) -> i32 {
-    return x + y;
+    x + y
 }
 ```
 
@@ -1155,7 +1156,7 @@ type Point = (u8, u8);
 let p: Point = (41, 68);
 ```
 
-### Structures
+### Structs
 
 A _structure_ is a nominal [structure type](#structure-types) defined with the
 keyword `struct`.
@@ -2614,21 +2615,21 @@ comma:
 ### Structure expressions
 
 There are several forms of structure expressions. A _structure expression_
-consists of the [path](#paths) of a [structure item](#structures), followed by
+consists of the [path](#paths) of a [structure item](#structs), followed by
 a brace-enclosed list of one or more comma-separated name-value pairs,
 providing the field values of a new instance of the structure. A field name
 can be any identifier, and is separated from its value expression by a colon.
 The location denoted by a structure field is mutable if and only if the
 enclosing structure is mutable.
 
 A _tuple structure expression_ consists of the [path](#paths) of a [structure
-item](#structures), followed by a parenthesized list of one or more
+item](#structs), followed by a parenthesized list of one or more
 comma-separated expressions (in other words, the path of a structure item
 followed by a tuple expression). The structure item must be a tuple structure
 item.
 
 A _unit-like structure expression_ consists only of the [path](#paths) of a
-[structure item](#structures).
+[structure item](#structs).
 
 The following are examples of structure expressions:
 
@@ -3145,7 +3146,7 @@ if` condition is evaluated. If all `if` and `else if` conditions evaluate to
 
 A `match` expression branches on a *pattern*. The exact form of matching that
 occurs depends on the pattern. Patterns consist of some combination of
-literals, destructured arrays or enum constructors, structures and tuples,
+literals, destructured arrays or enum constructors, structs and tuples,
 variable binding specifications, wildcards (`..`), and placeholders (`_`). A
 `match` expression has a *head expression*, which is the value to compare to
 the patterns. The type of the patterns must equal the type of the head
@@ -3469,7 +3470,7 @@ named reference to an [`enum` item](#enumerations).
 ### Recursive types
 
 Nominal types — [enumerations](#enumerated-types) and
-[structures](#structure-types) — may be recursive. That is, each `enum`
+[structs](#structure-types) — may be recursive. That is, each `enum`
 constructor or `struct` field may refer, directly or indirectly, to the
 enclosing `enum` or `struct` type itself. Such recursion has restrictions:
 
@@ -3497,7 +3498,7 @@ let a: List<i32> = List::Cons(7, Box::new(List::Cons(13, Box::new(List::Nil))));
 ### Pointer types
 
 All pointers in Rust are explicit first-class values. They can be copied,
-stored into data structures, and returned from functions. There are two
+stored into data structs, and returned from functions. There are two
 varieties of pointer in Rust:
 
 * References (`&`)
@@ -3897,7 +3898,7 @@ references to boxes are dropped.
 ### Variables
 
 A _variable_ is a component of a stack frame, either a named function parameter,
-an anonymous [temporary](#lvalues,-rvalues-and-temporaries), or a named local
+an anonymous [temporary](#lvalues-rvalues-and-temporaries), or a named local
 variable.
 
 A _local variable_ (or *stack-local* allocation) holds a value directly,
@@ -4036,10 +4037,6 @@ In general, `--crate-type=bin` or `--crate-type=lib` should be sufficient for
 all compilation needs, and the other options are just available if more
 fine-grained control is desired over the output format of a Rust crate.
 
-# Appendix: Rationales and design trade-offs
-
-*TODO*.
-
 # Appendix: Influences
 
 Rust is not a particularly original language, with design elements coming from

branches/tmp/src/doc/trpl/closures.md

@@ -411,8 +411,9 @@ fn factory() -> &(Fn(i32) -> i32) {
 ```
 
 Right. Because we have a reference, we need to give it a lifetime. But
-our `factory()` function takes no arguments, so elision doesn’t kick in
-here. What lifetime can we choose? `'static`:
+our `factory()` function takes no arguments, so
+[elision](lifetimes.html#lifetime-elision) doesn’t kick in here. Then what
+choices do we have? Try `'static`:
 
 ```rust,ignore
 fn factory() -> &'static (Fn(i32) -> i32) {
@@ -432,7 +433,7 @@ But we get another error:
 ```text
 error: mismatched types:
  expected `&'static core::ops::Fn(i32) -> i32`,
-    found `[closure <anon>:7:9: 7:20]`
+    found `[closure@<anon>:7:9: 7:20]`
 (expected &-ptr,
     found closure) [E0308]
          |x| x + num
@@ -441,21 +442,17 @@ error: mismatched types:
 ```
 
 This error is letting us know that we don’t have a `&'static Fn(i32) -> i32`,
-we have a `[closure <anon>:7:9: 7:20]`. Wait, what?
+we have a `[closure@<anon>:7:9: 7:20]`. Wait, what?
 
 Because each closure generates its own environment `struct` and implementation
 of `Fn` and friends, these types are anonymous. They exist just solely for
-this closure. So Rust shows them as `closure <anon>`, rather than some
+this closure. So Rust shows them as `closure@<anon>`, rather than some
 autogenerated name.
 
-But why doesn’t our closure implement `&'static Fn`? Well, as we discussed before,
-closures borrow their environment. And in this case, our environment is based
-on a stack-allocated `5`, the `num` variable binding. So the borrow has a lifetime
-of the stack frame. So if we returned this closure, the function call would be
-over, the stack frame would go away, and our closure is capturing an environment
-of garbage memory!
-
-So what to do? This _almost_ works:
+The error also points out that the return type is expected to be a reference,
+but what we are trying to return is not. Further, we cannot directly assign a
+`'static` lifetime to an object. So we'll take a different approach and return
+a "trait object" by `Box`ing up the `Fn`. This _almost_ works:
 
 ```rust,ignore
 fn factory() -> Box<Fn(i32) -> i32> {
@@ -471,7 +468,7 @@ assert_eq!(6, answer);
 # }
 ```
 
-We use a trait object, by `Box`ing up the `Fn`. There’s just one last problem:
+There’s just one last problem:
 
 ```text
 error: closure may outlive the current function, but it borrows `num`,
@@ -480,8 +477,12 @@ Box::new(|x| x + num)
          ^~~~~~~~~~~
 ```
 
-We still have a reference to the parent stack frame. With one last fix, we can
-make this work:
+Well, as we discussed before, closures borrow their environment. And in this
+case, our environment is based on a stack-allocated `5`, the `num` variable
+binding. So the borrow has a lifetime of the stack frame. So if we returned
+this closure, the function call would be over, the stack frame would go away,
+and our closure is capturing an environment of garbage memory! With one last
+fix, we can make this work:
 
 ```rust
 fn factory() -> Box<Fn(i32) -> i32> {

branches/tmp/src/liballoc/boxed.rs

@@ -80,11 +80,10 @@ use core::raw::{TraitObject};
 /// use std::boxed::HEAP;
 ///
 /// fn main() {
-///     let foo = box(HEAP) 5;
+///     let foo: Box<i32> = in HEAP { 5 };
 ///     let foo = box 5;
 /// }
 /// ```
-#[lang = "exchange_heap"]
 #[unstable(feature = "box_heap",
            reason = "may be renamed; uncertain about custom allocator design",
            issue = "27779")]

branches/tmp/src/libcollections/binary_heap.rs

@@ -167,12 +167,22 @@ use vec::{self, Vec};
 /// item's ordering relative to any other item, as determined by the `Ord`
 /// trait, changes while it is in the heap. This is normally only possible
 /// through `Cell`, `RefCell`, global state, I/O, or unsafe code.
-#[derive(Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct BinaryHeap<T> {
     data: Vec<T>,
 }
 
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T: Clone> Clone for BinaryHeap<T> {
+    fn clone(&self) -> Self {
+        BinaryHeap { data: self.data.clone() }
+    }
+
+    fn clone_from(&mut self, source: &Self) {
+        self.data.clone_from(&source.data);
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Ord> Default for BinaryHeap<T> {
     #[inline]

branches/tmp/src/libcollections/lib.rs

@@ -62,7 +62,7 @@
 #![feature(unsafe_no_drop_flag, filling_drop)]
 #![feature(decode_utf16)]
 #![feature(utf8_error)]
-#![cfg_attr(test, feature(rand, test))]
+#![cfg_attr(test, feature(clone_from_slice, rand, test))]
 
 #![feature(no_std)]
 #![no_std]

branches/tmp/src/libcollections/string.rs

@@ -30,7 +30,7 @@ use vec::Vec;
 use boxed::Box;
 
 /// A growable string stored as a UTF-8 encoded buffer.
-#[derive(Clone, PartialOrd, Eq, Ord)]
+#[derive(PartialOrd, Eq, Ord)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct String {
     vec: Vec<u8>,
@@ -765,6 +765,17 @@ impl fmt::Display for FromUtf16Error {
     }
 }
 
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Clone for String {
+    fn clone(&self) -> Self {
+        String { vec: self.vec.clone() }
+    }
+
+    fn clone_from(&mut self, source: &Self) {
+        self.vec.clone_from(&source.vec);
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl FromIterator<char> for String {
     fn from_iter<I: IntoIterator<Item=char>>(iterable: I) -> String {

branches/tmp/src/libcollections/vec.rs

@@ -1007,19 +1007,15 @@ impl<T:Clone> Clone for Vec<T> {
 
     fn clone_from(&mut self, other: &Vec<T>) {
         // drop anything in self that will not be overwritten
-        if self.len() > other.len() {
-            self.truncate(other.len())
-        }
+        self.truncate(other.len());
+        let len = self.len();
 
         // reuse the contained values' allocations/resources.
-        for (place, thing) in self.iter_mut().zip(other) {
-            place.clone_from(thing)
-        }
+        self.clone_from_slice(&other[..len]);
 
         // self.len <= other.len due to the truncate above, so the
         // slice here is always in-bounds.
-        let slice = &other[self.len()..];
-        self.push_all(slice);
+        self.push_all(&other[len..]);
     }
 }
 

branches/tmp/src/libcore/array.rs

@@ -35,14 +35,23 @@ use slice::{Iter, IterMut, SliceExt};
 ///
 /// This trait can be used to implement other traits on fixed-size arrays
 /// without causing much metadata bloat.
-pub trait FixedSizeArray<T> {
+///
+/// The trait is marked unsafe in order to restrict implementors to fixed-size
+/// arrays. User of this trait can assume that implementors have the exact
+/// layout in memory of a fixed size array (for example, for unsafe
+/// initialization).
+///
+/// Note that the traits AsRef and AsMut provide similar methods for types that
+/// may not be fixed-size arrays. Implementors should prefer those traits
+/// instead.
+pub unsafe trait FixedSizeArray<T> {
     /// Converts the array to immutable slice
     fn as_slice(&self) -> &[T];
     /// Converts the array to mutable slice
     fn as_mut_slice(&mut self) -> &mut [T];
 }
 
-impl<T, A: Unsize<[T]>> FixedSizeArray<T> for A {
+unsafe impl<T, A: Unsize<[T]>> FixedSizeArray<T> for A {
     #[inline]
     fn as_slice(&self) -> &[T] {
         self

branches/tmp/src/libcore/mem.rs

@@ -434,6 +434,11 @@ pub fn replace<T>(dest: &mut T, mut src: T) -> T {
 /// While this does call the argument's implementation of `Drop`, it will not
 /// release any borrows, as borrows are based on lexical scope.
 ///
+/// This effectively does nothing for
+/// [types which implement `Copy`](../../book/ownership.html#copy-types),
+/// e.g. integers. Such values are copied and _then_ moved into the function,
+/// so the value persists after this function call.
+///
 /// # Examples
 ///
 /// Basic usage:
@@ -486,6 +491,21 @@ pub fn replace<T>(dest: &mut T, mut src: T) -> T {
 /// let borrow = x.borrow();
 /// println!("{}", *borrow);
 /// ```
+///
+/// Integers and other types implementing `Copy` are unaffected by `drop()`
+///
+/// ```
+/// #[derive(Copy, Clone)]
+/// struct Foo(u8);
+///
+/// let x = 1;
+/// let y = Foo(2);
+/// drop(x); // a copy of `x` is moved and dropped
+/// drop(y); // a copy of `y` is moved and dropped
+///
+/// println!("x: {}, y: {}", x, y.0); // still available
+/// ```
+///
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub fn drop<T>(_x: T) { }

branches/tmp/src/librustc/middle/cfg/construct.rs

@@ -344,13 +344,12 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
                 self.straightline(expr, pred, [r, l].iter().map(|&e| &**e))
             }
 
-            hir::ExprBox(Some(ref l), ref r) |
             hir::ExprIndex(ref l, ref r) |
             hir::ExprBinary(_, ref l, ref r) => { // NB: && and || handled earlier
                 self.straightline(expr, pred, [l, r].iter().map(|&e| &**e))
             }
 
-            hir::ExprBox(None, ref e) |
+            hir::ExprBox(ref e) |
             hir::ExprAddrOf(_, ref e) |
             hir::ExprCast(ref e, _) |
             hir::ExprUnary(_, ref e) |

branches/tmp/src/librustc/middle/check_const.rs

@@ -568,8 +568,7 @@ fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>,
                             "user-defined operators are not allowed in {}s", v.msg());
             }
         }
-        hir::ExprBox(..) |
-        hir::ExprUnary(hir::UnUniq, _) => {
+        hir::ExprBox(_) => {
             v.add_qualif(ConstQualif::NOT_CONST);
             if v.mode != Mode::Var {
                 span_err!(v.tcx.sess, e.span, E0010,