diff options
| -rw-r--r-- | src/libcore/iter.rs | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/src/libcore/iter.rs b/src/libcore/iter.rs index 5895d871dbe..737ad0ae913 100644 --- a/src/libcore/iter.rs +++ b/src/libcore/iter.rs @@ -750,6 +750,7 @@ impl<A, B, T: ExactSize<A>, U: ExactSize<B>> ExactSize<(A, B)> for Zip<T, U> {} /// An double-ended iterator with the direction inverted #[deriving(Clone)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Rev<T> { iter: T } @@ -778,6 +779,7 @@ impl<A, T: DoubleEndedIterator<A> + RandomAccessIterator<A>> RandomAccessIterato } /// A mutable reference to an iterator +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct ByRef<'a, T> { iter: &'a mut T } @@ -1038,6 +1040,7 @@ impl<A, T: Clone + Iterator<A>> CloneableIterator for T { /// An iterator that repeats endlessly #[deriving(Clone)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Cycle<T> { orig: T, iter: T, @@ -1089,6 +1092,7 @@ impl<A, T: Clone + RandomAccessIterator<A>> RandomAccessIterator<A> for Cycle<T> /// An iterator which strings two iterators together #[deriving(Clone)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Chain<T, U> { a: T, b: U, @@ -1158,6 +1162,7 @@ for Chain<T, U> { /// An iterator which iterates two other iterators simultaneously #[deriving(Clone)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Zip<T, U> { a: T, b: U @@ -1236,6 +1241,7 @@ RandomAccessIterator<(A, B)> for Zip<T, U> { } /// An iterator which maps the values of `iter` with `f` +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Map<'a, A, B, T> { iter: T, f: |A|: 'a -> B @@ -1286,6 +1292,7 @@ impl<'a, A, B, T: RandomAccessIterator<A>> RandomAccessIterator<B> for Map<'a, A } /// An iterator which filters the elements of `iter` with `predicate` +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Filter<'a, A, T> { iter: T, predicate: |&A|: 'a -> bool @@ -1330,6 +1337,7 @@ impl<'a, A, T: DoubleEndedIterator<A>> DoubleEndedIterator<A> for Filter<'a, A, } /// An iterator which uses `f` to both filter and map elements from `iter` +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct FilterMap<'a, A, B, T> { iter: T, f: |A|: 'a -> Option<B> @@ -1374,6 +1382,7 @@ for FilterMap<'a, A, B, T> { /// An iterator which yields the current count and the element during iteration #[deriving(Clone)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Enumerate<T> { iter: T, count: uint @@ -1428,6 +1437,7 @@ impl<A, T: RandomAccessIterator<A>> RandomAccessIterator<(uint, A)> for Enumerat } /// An iterator with a `peek()` that returns an optional reference to the next element. +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Peekable<A, T> { iter: T, peeked: Option<A>, @@ -1478,6 +1488,7 @@ impl<'a, A, T: Iterator<A>> Peekable<A, T> { } /// An iterator which rejects elements while `predicate` is true +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct SkipWhile<'a, A, T> { iter: T, flag: bool, @@ -1516,6 +1527,7 @@ impl<'a, A, T: Iterator<A>> Iterator<A> for SkipWhile<'a, A, T> { } /// An iterator which only accepts elements while `predicate` is true +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct TakeWhile<'a, A, T> { iter: T, flag: bool, @@ -1551,6 +1563,7 @@ impl<'a, A, T: Iterator<A>> Iterator<A> for TakeWhile<'a, A, T> { /// An iterator which skips over `n` elements of `iter`. #[deriving(Clone)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Skip<T> { iter: T, n: uint @@ -1615,6 +1628,7 @@ impl<A, T: RandomAccessIterator<A>> RandomAccessIterator<A> for Skip<T> { /// An iterator which only iterates over the first `n` iterations of `iter`. #[deriving(Clone)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Take<T> { iter: T, n: uint @@ -1664,6 +1678,7 @@ impl<A, T: RandomAccessIterator<A>> RandomAccessIterator<A> for Take<T> { /// An iterator to maintain state while iterating another iterator +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Scan<'a, A, B, T, St> { iter: T, f: |&mut St, A|: 'a -> Option<B>, @@ -1688,6 +1703,7 @@ impl<'a, A, B, T: Iterator<A>, St> Iterator<B> for Scan<'a, A, B, T, St> { /// An iterator that maps each element to an iterator, /// and yields the elements of the produced iterators /// +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct FlatMap<'a, A, T, U> { iter: T, f: |A|: 'a -> U, @@ -1747,6 +1763,7 @@ impl<'a, /// An iterator that yields `None` forever after the underlying iterator /// yields `None` once. #[deriving(Clone)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Fuse<T> { iter: T, done: bool @@ -1819,6 +1836,7 @@ impl<T> Fuse<T> { /// An iterator that calls a function with a reference to each /// element before yielding it. +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] pub struct Inspect<'a, A, T> { iter: T, f: |&A|: 'a @@ -2298,4 +2316,3 @@ pub mod order { } } } - |