std::default_searcher (3) - Linux Manuals

std::default_searcher: std::default_searcher

NAME

std::default_searcher - std::default_searcher

Synopsis

Defined in header <functional>
template< class ForwardIt, class BinaryPredicate = std::equal_to<> > (since C++17)
class default_searcher;

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.
default_searcher is CopyConstructible and CopyAssignable.

Member functions

 std::default_searcher::default_searcher

default_searcher( ForwardIt pat_first, (since C++17)
ForwardIt pat_last, (until C++20)
BinaryPredicate pred = BinaryPredicate());
constexpr default_searcher( ForwardIt pat_first,
ForwardIt pat_last, (since C++20)
BinaryPredicate pred = BinaryPredicate());

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 > (since C++17)
std::pair<ForwardIt2, ForwardIt2> (until C++20)
operator()( ForwardIt2 first, ForwardIt2 last ) const;
template< class ForwardIt2 >
constexpr std::pair<ForwardIt2, ForwardIt2> (since C++20)
operator()( ForwardIt2 first, ForwardIt2 last ) const;

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

// Run this code

  #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()));
      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