41 lines
1.6 KiB
Rust
41 lines
1.6 KiB
Rust
// Copyright 2013 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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//! Container traits for extra
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use std::container::Mutable;
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/// A double-ended sequence that allows querying, insertion and deletion at both ends.
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pub trait Deque<T> : Mutable {
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/// Provide a reference to the front element, or None if the sequence is empty
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fn front<'a>(&'a self) -> Option<&'a T>;
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/// Provide a mutable reference to the front element, or None if the sequence is empty
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fn front_mut<'a>(&'a mut self) -> Option<&'a mut T>;
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/// Provide a reference to the back element, or None if the sequence is empty
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fn back<'a>(&'a self) -> Option<&'a T>;
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/// Provide a mutable reference to the back element, or None if the sequence is empty
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fn back_mut<'a>(&'a mut self) -> Option<&'a mut T>;
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/// Insert an element first in the sequence
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fn push_front(&mut self, elt: T);
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/// Insert an element last in the sequence
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fn push_back(&mut self, elt: T);
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/// Remove the last element and return it, or None if the sequence is empty
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fn pop_back(&mut self) -> Option<T>;
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/// Remove the first element and return it, or None if the sequence is empty
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fn pop_front(&mut self) -> Option<T>;
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}
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