std::default_searcher - cppreference.com (original) (raw)
| | | | | ------------------------------------------------------------------------------------------------------------------- | | ------------- | | template< class ForwardIt, class BinaryPredicate = std::equal_to<> > class default_searcher; | | (since C++17) |
A class suitable for use with Searcher overload of std::search that delegates the search operation to the pre-C++17 standard library's std::search.
std::default_searcher is CopyConstructible and CopyAssignable.
Contents
[edit] Member functions
std::default_searcher::default_searcher
| default_searcher( ForwardIt pat_first, ForwardIt pat_last, BinaryPredicate pred = BinaryPredicate() ); | | (since C++17) (constexpr since C++20) | | ----------------------------------------------------------------------------------------------------------- | | ------------------------------------- |
Constructs a std::default_searcher by storing copies of pat_first, pat_last, and pred.
Parameters
| pat_first, pat_last | - | a pair of iterators designating the string to be searched for |
|---|---|---|
| pred | - | a callable object used to determine equality |
Exceptions
Any exceptions thrown by the copy constructors of BinaryPredicate or ForwardIt.
std::default_searcher::operator()
| template< class ForwardIt2 > std::pair<ForwardIt2, ForwardIt2> operator()( ForwardIt2 first, ForwardIt2 last ) const; | | (since C++17) (constexpr since C++20) | | ---------------------------------------------------------------------------------------------------------------------------------------- | | ------------------------------------- |
The member function called by the Searcher overload of std::search to perform a search with this searcher.
Returns a pair of iterators i, j, where i is std::search(first, last, pat_first, pat_last, pred) and j is std::next(i, std::distance(pat_first, pat_last)) unless std::search returned last (no match), in which case j equals last as well.
Parameters
| first, last | - | a pair of iterators designating the string to be examined |
|---|
Return value
A pair of iterators to the first and one past last positions in [first, last) where a subsequence that compares equal to [pat_first, pat_last) as defined by pred is located, or a pair of copies of last otherwise.
[edit] Example
#include #include #include #include #include int main() { constexpr std::string_view in = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed " "do eiusmod tempor incididunt ut labore et dolore magna aliqua"; const std::string_view needle{"pisci"}; auto it = std::search(in.begin(), in.end(), std::default_searcher( needle.begin(), needle.end())); if (it != in.end()) std::cout << "The string " << std::quoted(needle) << " found at offset " << it - in.begin() << '\n'; else std::cout << "The string " << std::quoted(needle) << " not found\n"; }
Output:
The string "pisci" found at offset 43