indexmap/
util.rs

1use core::ops::{Bound, Range, RangeBounds};
2
3pub(crate) fn third<A, B, C>(t: (A, B, C)) -> C {
4    t.2
5}
6
7pub(crate) fn simplify_range<R>(range: R, len: usize) -> Range<usize>
8where
9    R: RangeBounds<usize>,
10{
11    let start = match range.start_bound() {
12        Bound::Unbounded => 0,
13        Bound::Included(&i) if i <= len => i,
14        Bound::Excluded(&i) if i < len => i + 1,
15        bound => panic!("range start {:?} should be <= length {}", bound, len),
16    };
17    let end = match range.end_bound() {
18        Bound::Unbounded => len,
19        Bound::Excluded(&i) if i <= len => i,
20        Bound::Included(&i) if i < len => i + 1,
21        bound => panic!("range end {:?} should be <= length {}", bound, len),
22    };
23    if start > end {
24        panic!(
25            "range start {:?} should be <= range end {:?}",
26            range.start_bound(),
27            range.end_bound()
28        );
29    }
30    start..end
31}
32
33pub(crate) fn try_simplify_range<R>(range: R, len: usize) -> Option<Range<usize>>
34where
35    R: RangeBounds<usize>,
36{
37    let start = match range.start_bound() {
38        Bound::Unbounded => 0,
39        Bound::Included(&i) if i <= len => i,
40        Bound::Excluded(&i) if i < len => i + 1,
41        _ => return None,
42    };
43    let end = match range.end_bound() {
44        Bound::Unbounded => len,
45        Bound::Excluded(&i) if i <= len => i,
46        Bound::Included(&i) if i < len => i + 1,
47        _ => return None,
48    };
49    if start > end {
50        return None;
51    }
52    Some(start..end)
53}
indexmap/util.rs

indexmap/
util.rs
