std::default_searcher
| Defined in header <functional>
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| 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.
Member functions
std::default_searcher::default_searcher
default_searcher( ForwardIt pat_first, ForwardIt pat_last, |
(since C++17) (constexpr since C++20) |
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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> |
(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.
Example
#include <algorithm> #include <functional> #include <iomanip> #include <iostream> #include <string_view> 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
See also
| searches for the first occurrence of a range of elements (function template) | |
| (C++17) |
Boyer-Moore search algorithm implementation (class template) |
| Boyer-Moore-Horspool search algorithm implementation (class template) |