ehttpd_range/
rangeext.rs

1//! Utilities to work with range bounds and ranges
2
3use std::ops::{Bound, Range, RangeBounds, RangeInclusive};
4
5/// An extension trait for ranges
6pub trait RangeExt<T>
7where
8    Self: Sized,
9{
10    /// Creates `Self` from the given range bounds and validates that it is within `min_incl` and `max_excl`
11    fn from_range_bounds<B>(bounds: B, min_incl: T, max_excl: T) -> Option<Self>
12    where
13        B: RangeBounds<T>;
14}
15
16/// Implements `RangeExt` for `RangeInclusive` with the given unsized integer
17macro_rules! impl_rangeext_range_uint {
18    ($uint:ty) => {
19        impl RangeExt<$uint> for Range<$uint> {
20            fn from_range_bounds<B>(bounds: B, min_incl: $uint, max_excl: $uint) -> Option<Self>
21            where
22                B: RangeBounds<$uint>,
23            {
24                // Compute the bounds
25                let start = match bounds.start_bound() {
26                    Bound::Included(start) => *start,
27                    Bound::Excluded(_) => unreachable!("excluded bounds are invalid for range starts"),
28                    Bound::Unbounded => min_incl,
29                };
30                let end = match bounds.end_bound() {
31                    Bound::Included(before_end) => before_end.saturating_add(1),
32                    Bound::Excluded(end) => *end,
33                    Bound::Unbounded => max_excl,
34                };
35
36                // Validate the range
37                if start < min_incl || start > max_excl {
38                    return None;
39                }
40                if end < min_incl || end > max_excl {
41                    return None;
42                }
43                Some(start..end)
44            }
45        }
46    };
47}
48impl_rangeext_range_uint!(u64);
49impl_rangeext_range_uint!(usize);
50
51/// Implements `RangeExt` for `RangeInclusive` with the given unsized integer
52macro_rules! impl_rangeext_rangeinclusive_uint {
53    ($uint:ty) => {
54        impl RangeExt<$uint> for RangeInclusive<$uint> {
55            fn from_range_bounds<B>(bounds: B, min_incl: $uint, max_excl: $uint) -> Option<Self>
56            where
57                B: RangeBounds<$uint>,
58            {
59                // Compute the bounds
60                let start = match bounds.start_bound() {
61                    Bound::Included(start) => *start,
62                    Bound::Excluded(_) => unreachable!("excluded bounds are invalid for range starts"),
63                    Bound::Unbounded => min_incl,
64                };
65                let end_incl = match bounds.end_bound() {
66                    Bound::Included(end) => *end,
67                    Bound::Excluded(after_end) => after_end.saturating_sub(1),
68                    Bound::Unbounded => max_excl.saturating_sub(1),
69                };
70
71                // Validate the range
72                if start < min_incl || start >= max_excl {
73                    return None;
74                }
75                if end_incl < min_incl || end_incl >= max_excl {
76                    return None;
77                }
78                Some(start..=end_incl)
79            }
80        }
81    };
82}
83impl_rangeext_rangeinclusive_uint!(u64);
84impl_rangeext_rangeinclusive_uint!(usize);
ehttpd_range/rangeext.rs

ehttpd_range/
rangeext.rs
