3a37ed4412
Used `HashMap` and `HashSet` as the base of most examples. Could change it up with different containers, but I don't think it's a big deal.
58 lines
1.5 KiB
Rust
58 lines
1.5 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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//! The `Default` trait for types which may have meaningful default values
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#![stable]
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/// A trait that types which have a useful default value should implement.
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pub trait Default {
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/// Return the "default value" for a type.
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///
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/// # Example
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///
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/// ```
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/// use std::default::Default;
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///
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/// let i: i8 = Default::default();
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/// let (x, y): (Option<String>, f64) = Default::default();
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/// let (a, b, (c, d)): (int, uint, (bool, bool)) = Default::default();
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/// ```
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fn default() -> Self;
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}
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macro_rules! default_impl(
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($t:ty, $v:expr) => {
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impl Default for $t {
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#[inline]
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fn default() -> $t { $v }
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}
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}
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)
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default_impl!((), ())
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default_impl!(bool, false)
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default_impl!(char, '\x00')
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default_impl!(uint, 0u)
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default_impl!(u8, 0u8)
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default_impl!(u16, 0u16)
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default_impl!(u32, 0u32)
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default_impl!(u64, 0u64)
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default_impl!(int, 0i)
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default_impl!(i8, 0i8)
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default_impl!(i16, 0i16)
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default_impl!(i32, 0i32)
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default_impl!(i64, 0i64)
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default_impl!(f32, 0.0f32)
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default_impl!(f64, 0.0f64)
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