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| 1 | +// Copyright 2014 The Rust Project Developers. See the COPYRIGHT |
| 2 | +// file at the top-level directory of this distribution and at |
| 3 | +// http://rust-lang.org/COPYRIGHT. |
| 4 | +// |
| 5 | +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| 6 | +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| 7 | +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| 8 | +// option. This file may not be copied, modified, or distributed |
| 9 | +// except according to those terms. |
| 10 | + |
| 11 | +use std::slice; |
| 12 | + |
| 13 | +/// Allows to view uniform tuples as slices |
| 14 | +pub trait TupleSlice<T> { |
| 15 | + fn as_slice(&self) -> &[T]; |
| 16 | + fn as_mut_slice(&mut self) -> &mut [T]; |
| 17 | +} |
| 18 | + |
| 19 | +macro_rules! impl_tuple_slice { |
| 20 | + ($tuple_type:ty, $size:expr) => { |
| 21 | + impl<T> TupleSlice<T> for $tuple_type { |
| 22 | + fn as_slice(&self) -> &[T] { |
| 23 | + unsafe { |
| 24 | + let ptr = &self.0 as *const T; |
| 25 | + slice::from_raw_parts(ptr, $size) |
| 26 | + } |
| 27 | + } |
| 28 | + |
| 29 | + fn as_mut_slice(&mut self) -> &mut [T] { |
| 30 | + unsafe { |
| 31 | + let ptr = &mut self.0 as *mut T; |
| 32 | + slice::from_raw_parts_mut(ptr, $size) |
| 33 | + } |
| 34 | + } |
| 35 | + } |
| 36 | + } |
| 37 | +} |
| 38 | + |
| 39 | +impl_tuple_slice!((T,T), 2); |
| 40 | +impl_tuple_slice!((T,T,T), 3); |
| 41 | +impl_tuple_slice!((T,T,T,T), 4); |
| 42 | +impl_tuple_slice!((T,T,T,T,T), 5); |
| 43 | +impl_tuple_slice!((T,T,T,T,T,T), 6); |
| 44 | +impl_tuple_slice!((T,T,T,T,T,T,T), 7); |
| 45 | +impl_tuple_slice!((T,T,T,T,T,T,T,T), 8); |
| 46 | + |
| 47 | +#[test] |
| 48 | +fn test_sliced_tuples() { |
| 49 | + let t2 = (100i32, 101i32); |
| 50 | + assert_eq!(t2.as_slice(), &[100i32, 101i32]); |
| 51 | + |
| 52 | + let t3 = (102i32, 103i32, 104i32); |
| 53 | + assert_eq!(t3.as_slice(), &[102i32, 103i32, 104i32]); |
| 54 | + |
| 55 | + let t4 = (105i32, 106i32, 107i32, 108i32); |
| 56 | + assert_eq!(t4.as_slice(), &[105i32, 106i32, 107i32, 108i32]); |
| 57 | + |
| 58 | + let t5 = (109i32, 110i32, 111i32, 112i32, 113i32); |
| 59 | + assert_eq!(t5.as_slice(), &[109i32, 110i32, 111i32, 112i32, 113i32]); |
| 60 | +} |
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