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Diffstat (limited to 'vendor/itertools/src/concat_impl.rs')
-rw-r--r-- | vendor/itertools/src/concat_impl.rs | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/vendor/itertools/src/concat_impl.rs b/vendor/itertools/src/concat_impl.rs new file mode 100644 index 000000000..450f7fce1 --- /dev/null +++ b/vendor/itertools/src/concat_impl.rs @@ -0,0 +1,22 @@ +use crate::Itertools; + +/// Combine all an iterator's elements into one element by using [`Extend`]. +/// +/// [`IntoIterator`]-enabled version of [`Itertools::concat`]. +/// +/// This combinator will extend the first item with each of the rest of the +/// items of the iterator. If the iterator is empty, the default value of +/// `I::Item` is returned. +/// +/// ```rust +/// use itertools::concat; +/// +/// let input = vec![vec![1], vec![2, 3], vec![4, 5, 6]]; +/// assert_eq!(concat(input), vec![1, 2, 3, 4, 5, 6]); +/// ``` +pub fn concat<I>(iterable: I) -> I::Item + where I: IntoIterator, + I::Item: Extend<<<I as IntoIterator>::Item as IntoIterator>::Item> + IntoIterator + Default +{ + iterable.into_iter().fold1(|mut a, b| { a.extend(b); a }).unwrap_or_else(<_>::default) +} |