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

pub trait DoubleEndedSearcher<'a>: ReverseSearcher<'a> { }
Unstable

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

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

Examples

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

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

Implementors