rust-lang/rust
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity

Stabilize iterator_repeat_with

Browse Source 
Fixes #48169
This commit is contained in:
Thayne McCombs
2018-05-29 23:30:16 -06:00
parent 63cd4a39ea
commit 87941b079a
5 changed files with 8 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
src/libcore/iter/sources.rs
View File

@@ -113,12 +113,12 @@ pub fn repeat<T: Clone>(elt: T) -> Repeat<T> {
///
/// [`repeat_with`]: fn.repeat_with.html
#[derive(Copy, Clone, Debug)]
#[unstable(feature = "iterator_repeat_with", issue = "48169")]
#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
pub struct RepeatWith<F> {
repeater: F
}
#[unstable(feature = "iterator_repeat_with", issue = "48169")]
#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
impl<A, F: FnMut() -> A> Iterator for RepeatWith<F> {
type Item = A;
@@ -129,13 +129,7 @@ impl<A, F: FnMut() -> A> Iterator for RepeatWith<F> {
fn size_hint(&self) -> (usize, Option<usize>) { (usize::MAX, None) }
}
#[unstable(feature = "iterator_repeat_with", issue = "48169")]
impl<A, F: FnMut() -> A> DoubleEndedIterator for RepeatWith<F> {
#[inline]
fn next_back(&mut self) -> Option<A> { self.next() }
}
#[unstable(feature = "iterator_repeat_with", issue = "48169")]
#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
impl<A, F: FnMut() -> A> FusedIterator for RepeatWith<F> {}
#[unstable(feature = "trusted_len", issue = "37572")]
@@ -158,19 +152,15 @@ unsafe impl<A, F: FnMut() -> A> TrustedLen for RepeatWith<F> {}
///
/// [`repeat`]: fn.repeat.html
///
/// An iterator produced by `repeat_with()` is a `DoubleEndedIterator`.
/// It is important to note that reversing `repeat_with(f)` will produce
/// the exact same sequence as the non-reversed iterator. In other words,
/// `repeat_with(f).rev().collect::<Vec<_>>()` is equivalent to
/// `repeat_with(f).collect::<Vec<_>>()`.
/// An iterator produced by `repeat_with()` is not a `DoubleEndedIterator`.
/// If you need `repeat_with()` to return a `DoubleEndedIterator`,
/// please open a GitHub issue explaining your use case.
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// #![feature(iterator_repeat_with)]
///
/// use std::iter;
///
/// // let's assume we have some value of a type that is not `Clone`
@@ -191,8 +181,6 @@ unsafe impl<A, F: FnMut() -> A> TrustedLen for RepeatWith<F> {}
/// Using mutation and going finite:
///
/// ```rust
/// #![feature(iterator_repeat_with)]
///
/// use std::iter;
///
/// // From the zeroth to the third power of two:
@@ -209,7 +197,7 @@ unsafe impl<A, F: FnMut() -> A> TrustedLen for RepeatWith<F> {}
/// assert_eq!(None, pow2.next());
/// ```
#[inline]
#[unstable(feature = "iterator_repeat_with", issue = "48169")]
#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
pub fn repeat_with<A, F: FnMut() -> A>(repeater: F) -> RepeatWith<F> {
RepeatWith { repeater }
}