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Showing content from https://en.cppreference.com/w/cpp/algorithm/../../cpp/../cpp/experimental/boyer_moore_searcher.html below:

std::experimental::boyer_moore_searcher, std::experimental::make_boyer_moore_searcher - cppreference.com

A searcher suitable for use with std::experimental::search that implements the Boyer-Moore string searching algorithm.

boyer_moore_searcher is CopyConstructible and CopyAssignable.

RandomIt1 must meet the requirements of LegacyRandomAccessIterator.

[edit] Member functions std::experimental::boyer_moore_searcher::boyer_moore_searcher boyer_moore_searcher( RandomIt1 pat_first, RandomIt1 pat_last, Hash hf = Hash(), BinaryPredicate pred = BinaryPredicate() );

Constructs a boyer_moore_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, and copy assignment operator of the value type of RandomIt1; or
the copy constructor and 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::experimental::boyer_moore_searcher::operator()

template< class RandomIt2 > RandomIt2 operator()( RandomIt2 first, RandomIt2 last ) const;

(until C++17) template< class RandomIt2 > std::pair<RandomIt2,RandomIt2> operator()( RandomIt2 first, RandomIt2 last ) const; (since C++17)

The member function called by std::experimental::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 first.

Otherwise, an iterator to the first position in [first, last) where a subsequence that compares equal to [pat_first, pat_last) as defined by pred is located, or a copy of last otherwise.

(until C++17)

If the pattern [pat_first, pat_last) is empty, returns 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 make_pair(last, last) otherwise.

(since C++17) [edit] Helper Functions template< class RandomIt, class Hash = std::hash<typename std::iterator_traits<RandomIt>::value_type>, class BinaryPredicate = std::equal_to<> > boyer_moore_searcher<RandomIt, Hash, BinaryPredicate> make_boyer_moore_searcher( RandomIt pat_first, RandomIt pat_last, Hash hf = Hash(), BinaryPredicate pred = BinaryPredicate()); (library fundamentals TS)

Helper function that constructs a std::experimental::boyer_moore_searcher using template argument deduction. Equivalent to return boyer_moore_searcher<RandomIt, Hash, BinaryPredicate>(pat_first, pat_last, hf, pred);

[edit] 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 [edit] Return value

A boyer_moore_searcher constructed with the arguments pat_first, pat_last, hf, and pred.

[edit] Example

#include <experimental/algorithm>
#include <experimental/functional>
#include <iostream>
#include <string>
 
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::experimental::search(in.begin(), in.end(),
                  std::experimental::make_boyer_moore_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

[edit] See also searches for the first occurrence of a range of elements
(function template) [edit]

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