66 lines
1.7 KiB
Rust
66 lines
1.7 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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/*! The Clone trait for types that cannot be "implicitly copied"
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In Rust, some simple types are "implicitly copyable" and when you
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assign them or pass them as arguments, the receiver will get a copy,
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leaving the original value in place. These types do not require
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allocation to copy and do not have finalizers (i.e. they do not
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contain owned pointers or implement `Drop`), so the compiler considers
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them cheap and safe to copy and automatically implements the `Copy`
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trait for them. For other types copies must be made explicitly,
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by convention implementing the `Clone` trait and calling the
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`clone` method.
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*/
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pub trait Clone {
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fn clone(&self) -> Self;
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}
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impl Clone for () {
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#[inline(always)]
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fn clone(&self) -> () { () }
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}
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impl<T:Clone> Clone for ~T {
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#[inline(always)]
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fn clone(&self) -> ~T { ~(**self).clone() }
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}
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macro_rules! clone_impl(
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($t:ty) => {
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impl Clone for $t {
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#[inline(always)]
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fn clone(&self) -> $t { *self }
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}
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}
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)
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clone_impl!(int)
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clone_impl!(i8)
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clone_impl!(i16)
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clone_impl!(i32)
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clone_impl!(i64)
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clone_impl!(uint)
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clone_impl!(u8)
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clone_impl!(u16)
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clone_impl!(u32)
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clone_impl!(u64)
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clone_impl!(float)
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clone_impl!(f32)
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clone_impl!(f64)
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clone_impl!(bool)
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clone_impl!(char)
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