index_type 0.7.0

Type-safe newtype indices for Rust
Documentation 
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

use core::ops::{Bound, Range, RangeBounds};

use crate::{IndexScalarType, IndexType};

/// Converts `RangeBounds<I>` to raw `usize` bounds.
#[inline]
pub fn range_bounds_to_raw<I: IndexType, R: RangeBounds<I>>(r: &R) -> (Bound<usize>, Bound<usize>) {
    (
        r.start_bound().map(|x| x.to_raw_index()),
        r.end_bound().map(|x| x.to_raw_index()),
    )
}

#[cold]
#[inline(never)]
#[track_caller]
pub(crate) fn panic_index_too_big<I: IndexType>(error: I::IndexTooBigError) -> ! {
    panic!("{}", error)
}

pub fn resolve_range_bounds<I: IndexType, R: RangeBounds<I>>(r: &R, length: I) -> Range<I> {
    let start = match r.start_bound() {
        core::ops::Bound::Included(i) => *i,
        core::ops::Bound::Excluded(i) => i
            .checked_add_scalar(I::Scalar::ONE)
            .expect("range out of bounds"),
        core::ops::Bound::Unbounded => I::ZERO,
    };

    let end = match r.end_bound() {
        core::ops::Bound::Included(i) => i
            .checked_add_scalar(I::Scalar::ONE)
            .expect("range out of bounds"),
        core::ops::Bound::Excluded(i) => *i,
        core::ops::Bound::Unbounded => length,
    };

    start..end
}