Difference between revisions of "cpp/utility/functional/default searcher"
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std::string needle = "pisci"; | std::string needle = "pisci"; | ||
auto it = std::search(in.begin(), in.end(), | auto it = std::search(in.begin(), in.end(), | ||
| − | std:: | + | std::default_searcher( |
| − | needle.begin(), needle.end())); | + | needle.begin(), needle.end())).first; |
if(it != in.end()) | if(it != in.end()) | ||
std::cout << "The string " << needle << " found at offset " | std::cout << "The string " << needle << " found at offset " | ||
Revision as of 09:28, 11 March 2017
| 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 Template:concept overload of std::search that delegates the search operation to the pre-C++17 standard library's std::search.
default_searcher is Template:concept and Template:concept.
Contents |
Member functions
std::default_searcher::default_searcher
| default_searcher( ForwardIt pat_first, ForwardIt pat_last, |
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Constructs a 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> |
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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 <iostream> #include <string> #include <algorithm> #include <functional> int main() { std::string in = "Lorem ipsum dolor sit amet, consectetur adipiscing elit," " sed do eiusmod tempor incididunt ut labore et dolore magna aliqua"; std::string needle = "pisci"; auto it = std::search(in.begin(), in.end(), std::default_searcher( needle.begin(), needle.end())).first; if(it != in.end()) std::cout << "The string " << needle << " found at offset " << it - in.begin() << '\n'; else std::cout << "The string " << 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) |
