parent
63cd4a39ea
commit
87941b079a
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@ -333,7 +333,7 @@ pub use self::range::Step;
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::sources::{Repeat, repeat};
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#[unstable(feature = "iterator_repeat_with", issue = "48169")]
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#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
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pub use self::sources::{RepeatWith, repeat_with};
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#[stable(feature = "iter_empty", since = "1.2.0")]
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pub use self::sources::{Empty, empty};
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@ -113,12 +113,12 @@ pub fn repeat<T: Clone>(elt: T) -> Repeat<T> {
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///
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/// [`repeat_with`]: fn.repeat_with.html
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#[derive(Copy, Clone, Debug)]
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#[unstable(feature = "iterator_repeat_with", issue = "48169")]
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#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
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pub struct RepeatWith<F> {
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repeater: F
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}
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#[unstable(feature = "iterator_repeat_with", issue = "48169")]
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#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
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impl<A, F: FnMut() -> A> Iterator for RepeatWith<F> {
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type Item = A;
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@ -129,13 +129,7 @@ impl<A, F: FnMut() -> A> Iterator for RepeatWith<F> {
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fn size_hint(&self) -> (usize, Option<usize>) { (usize::MAX, None) }
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}
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#[unstable(feature = "iterator_repeat_with", issue = "48169")]
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impl<A, F: FnMut() -> A> DoubleEndedIterator for RepeatWith<F> {
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#[inline]
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fn next_back(&mut self) -> Option<A> { self.next() }
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}
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#[unstable(feature = "iterator_repeat_with", issue = "48169")]
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#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
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impl<A, F: FnMut() -> A> FusedIterator for RepeatWith<F> {}
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#[unstable(feature = "trusted_len", issue = "37572")]
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@ -158,19 +152,15 @@ unsafe impl<A, F: FnMut() -> A> TrustedLen for RepeatWith<F> {}
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///
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/// [`repeat`]: fn.repeat.html
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///
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/// An iterator produced by `repeat_with()` is a `DoubleEndedIterator`.
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/// It is important to note that reversing `repeat_with(f)` will produce
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/// the exact same sequence as the non-reversed iterator. In other words,
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/// `repeat_with(f).rev().collect::<Vec<_>>()` is equivalent to
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/// `repeat_with(f).collect::<Vec<_>>()`.
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/// An iterator produced by `repeat_with()` is not a `DoubleEndedIterator`.
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/// If you need `repeat_with()` to return a `DoubleEndedIterator`,
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/// please open a GitHub issue explaining your use case.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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/// #![feature(iterator_repeat_with)]
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///
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/// use std::iter;
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///
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/// // let's assume we have some value of a type that is not `Clone`
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@ -191,8 +181,6 @@ unsafe impl<A, F: FnMut() -> A> TrustedLen for RepeatWith<F> {}
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/// Using mutation and going finite:
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///
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/// ```rust
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/// #![feature(iterator_repeat_with)]
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///
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/// use std::iter;
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///
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/// // From the zeroth to the third power of two:
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@ -209,7 +197,7 @@ unsafe impl<A, F: FnMut() -> A> TrustedLen for RepeatWith<F> {}
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/// assert_eq!(None, pow2.next());
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/// ```
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#[inline]
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#[unstable(feature = "iterator_repeat_with", issue = "48169")]
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#[stable(feature = "iterator_repeat_with", since = "1.28.0")]
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pub fn repeat_with<A, F: FnMut() -> A>(repeater: F) -> RepeatWith<F> {
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RepeatWith { repeater }
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}
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@ -89,7 +89,6 @@
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#![feature(fundamental)]
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#![feature(intrinsics)]
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#![feature(iterator_flatten)]
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#![feature(iterator_repeat_with)]
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#![feature(lang_items)]
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#![feature(link_llvm_intrinsics)]
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#![feature(never_type)]
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@ -1722,18 +1722,6 @@ fn test_repeat_with() {
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assert_eq!(repeat_with(|| NotClone(42)).size_hint(), (usize::MAX, None));
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}
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#[test]
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fn test_repeat_with_rev() {
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let mut curr = 1;
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let mut pow2 = repeat_with(|| { let tmp = curr; curr *= 2; tmp })
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.rev().take(4);
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assert_eq!(pow2.next(), Some(1));
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assert_eq!(pow2.next(), Some(2));
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assert_eq!(pow2.next(), Some(4));
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assert_eq!(pow2.next(), Some(8));
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assert_eq!(pow2.next(), None);
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}
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#[test]
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fn test_repeat_with_take() {
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let mut it = repeat_with(|| 42).take(3);
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@ -25,7 +25,6 @@
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#![feature(hashmap_internals)]
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#![feature(iterator_step_by)]
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#![feature(iterator_flatten)]
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#![feature(iterator_repeat_with)]
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#![feature(pattern)]
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#![feature(range_is_empty)]
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#![feature(raw)]
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