1f70acbf4c
This gets rid of the 'experimental' level, removes the non-staged_api case (i.e. stability levels for out-of-tree crates), and lets the staged_api attributes use 'unstable' and 'deprecated' lints. This makes the transition period to the full feature staging design a bit nicer.
102 lines
2.9 KiB
Rust
102 lines
2.9 KiB
Rust
// Copyright 2012-2013 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.
|
|
|
|
//! The `Clone` trait for types that cannot be 'implicitly copied'
|
|
//!
|
|
//! In Rust, some simple types are "implicitly copyable" and when you
|
|
//! assign them or pass them as arguments, the receiver will get a copy,
|
|
//! leaving the original value in place. These types do not require
|
|
//! allocation to copy and do not have finalizers (i.e. they do not
|
|
//! contain owned boxes or implement `Drop`), so the compiler considers
|
|
//! them cheap and safe to copy. For other types copies must be made
|
|
//! explicitly, by convention implementing the `Clone` trait and calling
|
|
//! the `clone` method.
|
|
|
|
#![stable]
|
|
|
|
use marker::Sized;
|
|
|
|
/// A common trait for cloning an object.
|
|
#[stable]
|
|
pub trait Clone : Sized {
|
|
/// Returns a copy of the value.
|
|
#[stable]
|
|
fn clone(&self) -> Self;
|
|
|
|
/// Perform copy-assignment from `source`.
|
|
///
|
|
/// `a.clone_from(&b)` is equivalent to `a = b.clone()` in functionality,
|
|
/// but can be overridden to reuse the resources of `a` to avoid unnecessary
|
|
/// allocations.
|
|
#[inline(always)]
|
|
#[unstable = "this function is rarely used"]
|
|
fn clone_from(&mut self, source: &Self) {
|
|
*self = source.clone()
|
|
}
|
|
}
|
|
|
|
#[stable]
|
|
impl<'a, T: ?Sized> Clone for &'a T {
|
|
/// Return a shallow copy of the reference.
|
|
#[inline]
|
|
fn clone(&self) -> &'a T { *self }
|
|
}
|
|
|
|
macro_rules! clone_impl {
|
|
($t:ty) => {
|
|
#[stable]
|
|
impl Clone for $t {
|
|
/// Return a deep copy of the value.
|
|
#[inline]
|
|
fn clone(&self) -> $t { *self }
|
|
}
|
|
}
|
|
}
|
|
|
|
clone_impl! { int }
|
|
clone_impl! { i8 }
|
|
clone_impl! { i16 }
|
|
clone_impl! { i32 }
|
|
clone_impl! { i64 }
|
|
|
|
clone_impl! { uint }
|
|
clone_impl! { u8 }
|
|
clone_impl! { u16 }
|
|
clone_impl! { u32 }
|
|
clone_impl! { u64 }
|
|
|
|
clone_impl! { f32 }
|
|
clone_impl! { f64 }
|
|
|
|
clone_impl! { () }
|
|
clone_impl! { bool }
|
|
clone_impl! { char }
|
|
|
|
macro_rules! extern_fn_clone {
|
|
($($A:ident),*) => (
|
|
#[unstable = "this may not be sufficient for fns with region parameters"]
|
|
impl<$($A,)* ReturnType> Clone for extern "Rust" fn($($A),*) -> ReturnType {
|
|
/// Return a copy of a function pointer
|
|
#[inline]
|
|
fn clone(&self) -> extern "Rust" fn($($A),*) -> ReturnType { *self }
|
|
}
|
|
)
|
|
}
|
|
|
|
extern_fn_clone! {}
|
|
extern_fn_clone! { A }
|
|
extern_fn_clone! { A, B }
|
|
extern_fn_clone! { A, B, C }
|
|
extern_fn_clone! { A, B, C, D }
|
|
extern_fn_clone! { A, B, C, D, E }
|
|
extern_fn_clone! { A, B, C, D, E, F }
|
|
extern_fn_clone! { A, B, C, D, E, F, G }
|
|
extern_fn_clone! { A, B, C, D, E, F, G, H }
|