Skip to content

add IntoBounds trait #136904

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Feb 14, 2025
Merged

add IntoBounds trait #136904

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions library/core/src/ops/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -182,6 +182,8 @@ pub use self::function::{Fn, FnMut, FnOnce};
#[stable(feature = "rust1", since = "1.0.0")]
pub use self::index::{Index, IndexMut};
pub(crate) use self::index_range::IndexRange;
#[unstable(feature = "range_into_bounds", issue = "136903")]
pub use self::range::IntoBounds;
#[stable(feature = "inclusive_range", since = "1.26.0")]
pub use self::range::{Bound, RangeBounds, RangeInclusive, RangeToInclusive};
#[unstable(feature = "one_sided_range", issue = "69780")]
Expand Down
82 changes: 82 additions & 0 deletions library/core/src/ops/range.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -831,6 +831,30 @@ pub trait RangeBounds<T: ?Sized> {
}
}

/// Used to convert a range into start and end bounds, consuming the
/// range by value.
///
/// `IntoBounds` is implemented by Rust’s built-in range types, produced
/// by range syntax like `..`, `a..`, `..b`, `..=c`, `d..e`, or `f..=g`.
#[unstable(feature = "range_into_bounds", issue = "136903")]
pub trait IntoBounds<T>: RangeBounds<T> {
/// Convert this range into the start and end bounds.
/// Returns `(start_bound, end_bound)`.
///
/// # Examples
///
/// ```
/// #![feature(range_into_bounds)]
///
/// use std::ops::Bound::*;
/// use std::ops::IntoBounds;
///
/// assert_eq!((0..5).into_bounds(), (Included(0), Excluded(5)));
/// assert_eq!((..=7).into_bounds(), (Unbounded, Included(7)));
/// ```
fn into_bounds(self) -> (Bound<T>, Bound<T>);
}

use self::Bound::{Excluded, Included, Unbounded};

#[stable(feature = "collections_range", since = "1.28.0")]
Expand All @@ -843,6 +867,13 @@ impl<T: ?Sized> RangeBounds<T> for RangeFull {
}
}

#[unstable(feature = "range_into_bounds", issue = "136903")]
impl<T> IntoBounds<T> for RangeFull {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(Unbounded, Unbounded)
}
}

#[stable(feature = "collections_range", since = "1.28.0")]
impl<T> RangeBounds<T> for RangeFrom<T> {
fn start_bound(&self) -> Bound<&T> {
Expand All @@ -853,6 +884,13 @@ impl<T> RangeBounds<T> for RangeFrom<T> {
}
}

#[unstable(feature = "range_into_bounds", issue = "136903")]
impl<T> IntoBounds<T> for RangeFrom<T> {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(Included(self.start), Unbounded)
}
}

#[stable(feature = "collections_range", since = "1.28.0")]
impl<T> RangeBounds<T> for RangeTo<T> {
fn start_bound(&self) -> Bound<&T> {
Expand All @@ -863,6 +901,13 @@ impl<T> RangeBounds<T> for RangeTo<T> {
}
}

#[unstable(feature = "range_into_bounds", issue = "136903")]
impl<T> IntoBounds<T> for RangeTo<T> {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(Unbounded, Excluded(self.end))
}
}

#[stable(feature = "collections_range", since = "1.28.0")]
impl<T> RangeBounds<T> for Range<T> {
fn start_bound(&self) -> Bound<&T> {
Expand All @@ -873,6 +918,13 @@ impl<T> RangeBounds<T> for Range<T> {
}
}

#[unstable(feature = "range_into_bounds", issue = "136903")]
impl<T> IntoBounds<T> for Range<T> {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(Included(self.start), Excluded(self.end))
}
}

#[stable(feature = "collections_range", since = "1.28.0")]
impl<T> RangeBounds<T> for RangeInclusive<T> {
fn start_bound(&self) -> Bound<&T> {
Expand All @@ -889,6 +941,22 @@ impl<T> RangeBounds<T> for RangeInclusive<T> {
}
}

#[unstable(feature = "range_into_bounds", issue = "136903")]
impl<T> IntoBounds<T> for RangeInclusive<T> {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(
Included(self.start),
if self.exhausted {
// When the iterator is exhausted, we usually have start == end,
// but we want the range to appear empty, containing nothing.
Excluded(self.end)
} else {
Included(self.end)
},
)
}
}

#[stable(feature = "collections_range", since = "1.28.0")]
impl<T> RangeBounds<T> for RangeToInclusive<T> {
fn start_bound(&self) -> Bound<&T> {
Expand All @@ -899,6 +967,13 @@ impl<T> RangeBounds<T> for RangeToInclusive<T> {
}
}

#[unstable(feature = "range_into_bounds", issue = "136903")]
impl<T> IntoBounds<T> for RangeToInclusive<T> {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(Unbounded, Included(self.end))
}
}

#[stable(feature = "collections_range", since = "1.28.0")]
impl<T> RangeBounds<T> for (Bound<T>, Bound<T>) {
fn start_bound(&self) -> Bound<&T> {
Expand All @@ -918,6 +993,13 @@ impl<T> RangeBounds<T> for (Bound<T>, Bound<T>) {
}
}

#[unstable(feature = "range_into_bounds", issue = "136903")]
impl<T> IntoBounds<T> for (Bound<T>, Bound<T>) {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
self
}
}

#[stable(feature = "collections_range", since = "1.28.0")]
impl<'a, T: ?Sized + 'a> RangeBounds<T> for (Bound<&'a T>, Bound<&'a T>) {
fn start_bound(&self) -> Bound<&T> {
Expand Down
28 changes: 27 additions & 1 deletion library/core/src/range.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,9 @@ pub use iter::{IterRange, IterRangeFrom, IterRangeInclusive};
#[doc(inline)]
pub use crate::iter::Step;
#[doc(inline)]
pub use crate::ops::{Bound, OneSidedRange, RangeBounds, RangeFull, RangeTo, RangeToInclusive};
pub use crate::ops::{
Bound, IntoBounds, OneSidedRange, RangeBounds, RangeFull, RangeTo, RangeToInclusive,
};

/// A (half-open) range bounded inclusively below and exclusively above
/// (`start..end` in a future edition).
Expand Down Expand Up @@ -175,6 +177,14 @@ impl<T> RangeBounds<T> for Range<&T> {
}
}

// #[unstable(feature = "range_into_bounds", issue = "136903")]
#[unstable(feature = "new_range_api", issue = "125687")]
impl<T> IntoBounds<T> for Range<T> {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(Included(self.start), Excluded(self.end))
}
}

#[unstable(feature = "new_range_api", issue = "125687")]
impl<T> From<Range<T>> for legacy::Range<T> {
#[inline]
Expand Down Expand Up @@ -343,6 +353,14 @@ impl<T> RangeBounds<T> for RangeInclusive<&T> {
}
}

// #[unstable(feature = "range_into_bounds", issue = "136903")]
#[unstable(feature = "new_range_api", issue = "125687")]
impl<T> IntoBounds<T> for RangeInclusive<T> {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(Included(self.start), Included(self.end))
}
}

#[unstable(feature = "new_range_api", issue = "125687")]
impl<T> From<RangeInclusive<T>> for legacy::RangeInclusive<T> {
#[inline]
Expand Down Expand Up @@ -479,6 +497,14 @@ impl<T> RangeBounds<T> for RangeFrom<&T> {
}
}

// #[unstable(feature = "range_into_bounds", issue = "136903")]
#[unstable(feature = "new_range_api", issue = "125687")]
impl<T> IntoBounds<T> for RangeFrom<T> {
fn into_bounds(self) -> (Bound<T>, Bound<T>) {
(Included(self.start), Unbounded)
}
}

#[unstable(feature = "new_range_api", issue = "125687")]
impl<T> From<RangeFrom<T>> for legacy::RangeFrom<T> {
#[inline]
Expand Down
Loading