src/libcore/array.rs

   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 //! Implementations of things like `Eq` for fixed-length arrays
  12 //! up to a certain length. Eventually we should able to generalize
  13 //! to all lengths.
  14
  15 #![doc(primitive = "array")]
  16 #![unstable(feature = "fixed_size_array",
  17             reason = "traits and impls are better expressed through generic \
  18                       integer constants")]
  19
  20 use clone::Clone;
  21 use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
  22 use convert::{AsRef, AsMut};
  23 use fmt;
  24 use hash::{Hash, self};
  25 use iter::IntoIterator;
  26 use marker::{Copy, Sized};
  27 use option::Option;
  28 use slice::{Iter, IterMut, SliceExt};
  29
  30 /// Utility trait implemented only on arrays of fixed size
  31 ///
  32 /// This trait can be used to implement other traits on fixed-size arrays
  33 /// without causing much metadata bloat.
  34 pub trait FixedSizeArray<T> {
  35     /// Converts the array to immutable slice
  36     fn as_slice(&self) -> &[T];
  37     /// Converts the array to mutable slice
  38     fn as_mut_slice(&mut self) -> &mut [T];
  39 }
  40
  41 // macro for implementing n-ary tuple functions and operations
  42 macro_rules! array_impls {
  43     ($($N:expr)+) => {
  44         $(
  45             impl<T> FixedSizeArray<T> for [T; $N] {
  46                 #[inline]
  47                 fn as_slice(&self) -> &[T] {
  48                     &self[..]
  49                 }
  50                 #[inline]
  51                 fn as_mut_slice(&mut self) -> &mut [T] {
  52                     &mut self[..]
  53                 }
  54             }
  55
  56             impl<T> AsRef<[T]> for [T; $N] {
  57                 #[inline]
  58                 fn as_ref(&self) -> &[T] {
  59                     &self[..]
  60                 }
  61             }
  62
  63             impl<T> AsMut<[T]> for [T; $N] {
  64                 #[inline]
  65                 fn as_mut(&mut self) -> &mut [T] {
  66                     &mut self[..]
  67                 }
  68             }
  69
  70             #[stable(feature = "rust1", since = "1.0.0")]
  71             impl<T:Copy> Clone for [T; $N] {
  72                 fn clone(&self) -> [T; $N] {
  73                     *self
  74                 }
  75             }
  76
  77             #[stable(feature = "rust1", since = "1.0.0")]
  78             impl<T: Hash> Hash for [T; $N] {
  79                 fn hash<H: hash::Hasher>(&self, state: &mut H) {
  80                     Hash::hash(&self[..], state)
  81                 }
  82             }
  83
  84             #[stable(feature = "rust1", since = "1.0.0")]
  85             impl<T: fmt::Debug> fmt::Debug for [T; $N] {
  86                 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  87                     fmt::Debug::fmt(&&self[..], f)
  88                 }
  89             }
  90
  91             #[stable(feature = "rust1", since = "1.0.0")]
  92             impl<'a, T> IntoIterator for &'a [T; $N] {
  93                 type Item = &'a T;
  94                 type IntoIter = Iter<'a, T>;
  95
  96                 fn into_iter(self) -> Iter<'a, T> {
  97                     self.iter()
  98                 }
  99             }
 100
 101             #[stable(feature = "rust1", since = "1.0.0")]
 102             impl<'a, T> IntoIterator for &'a mut [T; $N] {
 103                 type Item = &'a mut T;
 104                 type IntoIter = IterMut<'a, T>;
 105
 106                 fn into_iter(self) -> IterMut<'a, T> {
 107                     self.iter_mut()
 108                 }
 109             }
 110
 111             // NOTE: some less important impls are omitted to reduce code bloat
 112             __impl_slice_eq1! { [A; $N], [B; $N] }
 113             __impl_slice_eq2! { [A; $N], [B] }
 114             __impl_slice_eq2! { [A; $N], &'b [B] }
 115             __impl_slice_eq2! { [A; $N], &'b mut [B] }
 116             // __impl_slice_eq2! { [A; $N], &'b [B; $N] }
 117             // __impl_slice_eq2! { [A; $N], &'b mut [B; $N] }
 118
 119             #[stable(feature = "rust1", since = "1.0.0")]
 120             impl<T:Eq> Eq for [T; $N] { }
 121
 122             #[stable(feature = "rust1", since = "1.0.0")]
 123             impl<T:PartialOrd> PartialOrd for [T; $N] {
 124                 #[inline]
 125                 fn partial_cmp(&self, other: &[T; $N]) -> Option<Ordering> {
 126                     PartialOrd::partial_cmp(&&self[..], &&other[..])
 127                 }
 128                 #[inline]
 129                 fn lt(&self, other: &[T; $N]) -> bool {
 130                     PartialOrd::lt(&&self[..], &&other[..])
 131                 }
 132                 #[inline]
 133                 fn le(&self, other: &[T; $N]) -> bool {
 134                     PartialOrd::le(&&self[..], &&other[..])
 135                 }
 136                 #[inline]
 137                 fn ge(&self, other: &[T; $N]) -> bool {
 138                     PartialOrd::ge(&&self[..], &&other[..])
 139                 }
 140                 #[inline]
 141                 fn gt(&self, other: &[T; $N]) -> bool {
 142                     PartialOrd::gt(&&self[..], &&other[..])
 143                 }
 144             }
 145
 146             #[stable(feature = "rust1", since = "1.0.0")]
 147             impl<T:Ord> Ord for [T; $N] {
 148                 #[inline]
 149                 fn cmp(&self, other: &[T; $N]) -> Ordering {
 150                     Ord::cmp(&&self[..], &&other[..])
 151                 }
 152             }
 153         )+
 154     }
 155 }
 156
 157 array_impls! {
 158      0  1  2  3  4  5  6  7  8  9
 159     10 11 12 13 14 15 16 17 18 19
 160     20 21 22 23 24 25 26 27 28 29
 161     30 31 32
 162 }