Trait core::str::pattern::DoubleEndedSearcher [] [src]

pub trait DoubleEndedSearcher<'a>: ReverseSearcher<'a> { }
🔬 This is a nightly-only experimental API. (pattern #27721)

API not fully fleshed out and ready to be stabilized

A marker trait to express that a ReverseSearcher can be used for a DoubleEndedIterator implementation.

For this, the impl of Searcher and ReverseSearcher need to follow these conditions:


char::Searcher is a DoubleEndedSearcher because searching for a char only requires looking at one at a time, which behaves the same from both ends.

(&str)::Searcher is not a DoubleEndedSearcher because the pattern "aa" in the haystack "aaa" matches as either "[aa]a" or "a[aa]", depending from which side it is searched.