提交 fcf25ae8 编写于 作者: B bors

auto merge of #14019 : brson/rust/docs, r=alexcrichton

Just small bits of polish.
......@@ -14,32 +14,6 @@
use intrinsics;
use ptr::copy_nonoverlapping_memory;
/// Casts the value at `src` to U. The two types must have the same length.
#[inline]
pub unsafe fn transmute_copy<T, U>(src: &T) -> U {
let mut dest: U = mem::uninit();
let dest_ptr: *mut u8 = transmute(&mut dest);
let src_ptr: *u8 = transmute(src);
copy_nonoverlapping_memory(dest_ptr, src_ptr, mem::size_of::<U>());
dest
}
/**
* Move a thing into the void
*
* The forget function will take ownership of the provided value but neglect
* to run any required cleanup or memory-management operations on it.
*/
#[inline]
pub unsafe fn forget<T>(thing: T) { intrinsics::forget(thing); }
/**
* Force-increment the reference count on a shared box. If used
* carelessly, this can leak the box.
*/
#[inline]
pub unsafe fn bump_box_refcount<T>(t: @T) { forget(t); }
/**
* Transform a value of one type into a value of another type.
* Both types must have the same size and alignment.
......@@ -54,10 +28,29 @@ pub unsafe fn transmute_copy<T, U>(src: &T) -> U {
* ```
*/
#[inline]
pub unsafe fn transmute<L, G>(thing: L) -> G {
pub unsafe fn transmute<T, U>(thing: T) -> U {
intrinsics::transmute(thing)
}
/**
* Move a thing into the void
*
* The forget function will take ownership of the provided value but neglect
* to run any required cleanup or memory-management operations on it.
*/
#[inline]
pub unsafe fn forget<T>(thing: T) { intrinsics::forget(thing); }
/// Casts the value at `src` to U. The two types must have the same length.
#[inline]
pub unsafe fn transmute_copy<T, U>(src: &T) -> U {
let mut dest: U = mem::uninit();
let dest_ptr: *mut u8 = transmute(&mut dest);
let src_ptr: *u8 = transmute(src);
copy_nonoverlapping_memory(dest_ptr, src_ptr, mem::size_of::<U>());
dest
}
/// Coerce an immutable reference to be mutable.
#[inline]
#[deprecated="casting &T to &mut T is undefined behaviour: use Cell<T>, RefCell<T> or Unsafe<T>"]
......@@ -106,7 +99,7 @@ pub unsafe fn copy_lifetime_vec<'a,S,T>(_ptr: &'a [S], ptr: &T) -> &'a T {
#[cfg(test)]
mod tests {
use cast::{bump_box_refcount, transmute};
use cast::transmute;
use raw;
use realstd::str::StrAllocating;
......@@ -115,21 +108,6 @@ fn test_transmute_copy() {
assert_eq!(1u, unsafe { ::cast::transmute_copy(&1) });
}
#[test]
fn test_bump_managed_refcount() {
unsafe {
let managed = @"box box box".to_owned(); // refcount 1
bump_box_refcount(managed); // refcount 2
let ptr: *int = transmute(managed); // refcount 2
let _box1: @~str = ::cast::transmute_copy(&ptr);
let _box2: @~str = ::cast::transmute_copy(&ptr);
assert!(*_box1 == "box box box".to_owned());
assert!(*_box2 == "box box box".to_owned());
// Will destroy _box1 and _box2. Without the bump, this would
// use-after-free. With too many bumps, it would leak.
}
}
#[test]
fn test_transmute() {
unsafe {
......
......@@ -8,7 +8,7 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Types dealing with dynamic mutability
//! Types that provide interior mutability.
use clone::Clone;
use cmp::Eq;
......
......@@ -8,6 +8,8 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// FIXME: talk about offset, copy_memory, copy_nonoverlapping_memory
//! Conveniences for working with unsafe pointers, the `*T`, and `*mut T` types.
//!
//! Working with unsafe pointers in Rust is fairly uncommon,
......
......@@ -81,7 +81,7 @@
//! memory types, including [`atomics`](sync/atomics/index.html).
//!
//! Common types of I/O, including files, TCP, UPD, pipes, Unix domain sockets,
//! timers, and process spawning, are defined in the [`io`](io/index.html).
//! timers, and process spawning, are defined in the [`io`](io/index.html) module.
//!
//! Rust's I/O and concurrency depends on a small runtime interface
//! that lives, along with its support code, in mod [`rt`](rt/index.html).
......@@ -90,10 +90,11 @@
//!
//! ## The Rust prelude and macros
//!
//! Finally, the [`prelude`](prelude/index.html) defines a set of
//! Finally, the [`prelude`](prelude/index.html) defines a
//! common set of traits, types, and functions that are made available
//! to all code by default. [`macros`](macros/index.html) contains
//! all the standard macros, such as `assert!`, `fail!`, `println!`.
//! all the standard macros, such as `assert!`, `fail!`, `println!`,
//! and `format!`, also available to all Rust code.
#![crate_id = "std#0.11-pre"]
#![comment = "The Rust standard library"]
......
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