std::boyer_moore_horspool_searcher(3)

NAME
std::boyer_moore_horspool_searcher - std::boyer_moore_horspool_searcher

Synopsis
   Defined in header <functional>
   template< class RandomIt1,
             class Hash = std::hash<typename
   std::iterator_traits<RandomIt1>::value_type>, (since C++17)
             class BinaryPredicate = std::equal_to<> >
   class boyer_moore_horspool_searcher;
   A searcher suitable for use with the Searcher overload of std::search that
   implements the Boyer-Moore-Horspool string searching algorithm.
   std::boyer_moore_horspool_searcher is CopyConstructible and CopyAssignable.
   RandomIt1 must meet the requirements of LegacyRandomAccessIterator.

Member functions
std::boyer_moore_horspool_searcher::boyer_moore_horspool_searcher
   boyer_moore_horspool_searcher( RandomIt1 pat_first,
                        RandomIt1 pat_last,
                        Hash hf = Hash(),
                        BinaryPredicate pred = BinaryPredicate() );
   Constructs a std::boyer_moore_horspool_searcher by storing copies of pat_first,
   pat_last, hf, and pred, setting up any necessary internal data structures.
   The value type of RandomIt1 must be DefaultConstructible, CopyConstructible and
   CopyAssignable.
   For any two values A and B of the type std::iterator_traits<RandomIt1>::value_type,
   if pred(A, B) == true, then hf(A) == hf(B) shall be true.

Parameters
   pat_first, pat_last - a pair of iterators designating the string to be searched for
   hf - a callable object used to hash the elements of the string
   pred - a callable object used to determine equality

Exceptions
   Any exceptions thrown by
     * the copy constructor of RandomIt1;
     * the default constructor, copy constructor, or copy assignment operator of the
       value type of RandomIt1; or
     * the copy constructor or function call operator of BinaryPredicate or Hash.
   May also throw std::bad_alloc if additional memory required for internal data
   structures cannot be allocated. std::boyer_moore_horspool_searcher::operator()
   template< class RandomIt2 >
   std::pair<RandomIt2, RandomIt2> operator()( RandomIt2 first, RandomIt2 last )
   const;
   The member function called by the Searcher overload of std::search to perform a
   search with this searcher. RandomIt2 must meet the requirements of
   LegacyRandomAccessIterator.
   RandomIt1 and RandomIt2 must have the same value type.

Parameters
   first, last - a pair of iterators designating the string to be examined

Return value
   If the pattern [pat_first, pat_last) is empty, returns std::make_pair(first, first).
   Otherwise, returns 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 std::make_pair(last, last) otherwise.

Notes
         Feature-test macro Value Std Feature
   __cpp_lib_boyer_moore_searcher 201603L (C++17) searchers

Example
// Run this code
 #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::boyer_moore_horspool_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
   search searches for a range of elements
                        (function template)
   default_searcher standard C++ library search algorithm implementation
   (C++17) (class template)
   boyer_moore_searcher Boyer-Moore search algorithm implementation
   (C++17) (class template)