raw 0.0.5

Utilities for unsafely manipulating raw representations in Rust
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use rawslice::{RawSlice, RawMutSlice, SliceRawExt};

/// A wrapper for a slice that provides unchecked versions of the standard operations.
pub struct UncheckedSlice<'a, T: 'a > {
    slice: &'a [T],
}

/// A wrapper for a mutable slice that provides unchecked versions of the standard operations.
pub struct UncheckedMutSlice<'a, T: 'a> {
    slice: &'a mut [T],
}


pub trait SliceUncheckedExt<T> {
    /// Gets a version of the slice where all operations aren't bounds checked.
    fn as_unchecked<'a>(&'a self) -> UncheckedSlice<'a, T>;

    /// Gets a mutable version of the slice where all operations aren't bounds checked.
    fn as_unchecked_mut<'a>(&'a mut self) -> UncheckedMutSlice<'a, T>;
}

impl<T> SliceUncheckedExt<T> for [T] {
    fn as_unchecked<'a>(&'a self) -> UncheckedSlice<'a, T> {
        UncheckedSlice::new(self)
    }

    fn as_unchecked_mut<'a>(&'a mut self) -> UncheckedMutSlice<'a, T> {
        UncheckedMutSlice::new(self)
    }
}



impl<'a, T> UncheckedSlice<'a, T> {
    /// Makes a new unchecked slice from a slice.
    pub fn new(slice: &'a [T]) -> UncheckedSlice<'a, T> {
        UncheckedSlice{ slice: slice }
    }

    /// Gets the length of the slice.
    pub fn len(&self) -> usize {
        self.slice.len()
    }

    /// Converts the unchecked slice back into a checked one.
    pub fn as_slice(self) -> &'a [T] {
        self.slice
    }

    /// Gets a subslice of this one.
    pub unsafe fn slice<'b>(&'b self, from: usize, to: usize) -> UncheckedSlice<'b, T> {
        UncheckedSlice::new(self.slice.as_raw().slice(from, to).as_slice())
    }

    /// Gets a subslice from the given index to its end.
    pub unsafe fn slice_from<'b>(&'b self, from: usize) -> UncheckedSlice<'b, T> {
        self.slice(from, self.len())
    }

    /// Gets a subslice from 0 to the given index.
    pub unsafe fn slice_to<'b>(&'b self, to: usize) -> UncheckedSlice<'b, T> {
        self.slice(0, to)
    }

    /// Splits the given slice into two disjoint slices at the given index.
    pub unsafe fn split_at<'b>(&'b self, at: usize) -> (UncheckedSlice<'b, T>, UncheckedSlice<'b, T>) {
        (self.slice_to(at), self.slice_from(at))
    }

    /// Gets the value at the given index.
    pub unsafe fn get(&self, index: usize) ->  &T {
        self.slice.as_raw().get(index)
    }
}

impl<'a, T> UncheckedMutSlice<'a, T> {
    /// Makes a new unchecked slice from a slice.
    pub fn new(slice: &'a mut [T]) -> UncheckedMutSlice<'a, T> {
        UncheckedMutSlice{ slice: slice }
    }

    /// Gets the length of the slice.
    pub fn len(&self) -> usize {
        self.slice.len()
    }

    /// Converts the unchecked slice back into a checked one.
    pub fn as_slice(self) -> &'a [T] {
        self.slice
    }

    /// Converts the unchecked slice back into a mutable checked one.
    pub fn as_mut_slice(self) -> &'a mut [T] {
        self.slice
    }

    /// Gets a subslice of this one.
    pub unsafe fn slice<'b>(&'b mut self, from: usize, to: usize) -> UncheckedMutSlice<'b, T> {
        UncheckedMutSlice::new(self.slice.as_mut_raw().slice(from, to).as_mut_slice())
    }

    /// Gets a subslice from the given index to its end.
    pub unsafe fn slice_from<'b>(&'b mut self, from: usize) -> UncheckedMutSlice<'b, T> {
        let len = self.len();
        self.slice(from, len)
    }

    /// Gets a subslice from 0 to the given index.
    pub unsafe fn slice_to<'b>(&'b mut self, to: usize) -> UncheckedMutSlice<'b, T> {
        self.slice(0, to)
    }

    /// Splits the given slice into two disjoint slices at the given index.
    pub unsafe fn split_at<'b>(&'b mut self, at: usize) ->
            (UncheckedMutSlice<'b, T>, UncheckedMutSlice<'b, T>) {
        let raw = self.slice.as_mut_raw();
        (raw.slice_to(at).as_mut_slice().as_unchecked_mut(),
        raw.slice_from(at).as_mut_slice().as_unchecked_mut())
    }

    /// Gets the value at the given index.
    pub unsafe fn get(&mut self, index: usize) ->  &T {
        self.slice.as_mut_raw().get_mut(index)
    }

    /// Gets the value at the given index mutably.
    pub unsafe fn get_mut(&mut self, index: usize) ->  &mut T {
        self.slice.as_mut_raw().get_mut(index)
    }
}