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Defined in header <functional> | ||
template<class RandomIt1, class Hash=std::hash<typenamestd::iterator_traits<RandomIt1>::value_type>, | (since C++17) | |
A searcher suitable for use with theSearcher overload ofstd::search that implements theBoyer-Moore string searching algorithm.
std::boyer_moore_searcher
isCopyConstructible andCopyAssignable.
RandomIt1
must meet the requirements ofLegacyRandomAccessIterator.
Contents |
boyer_moore_searcher( RandomIt1 pat_first, RandomIt1 pat_last, | ||
Constructs astd::boyer_moore_searcher
by storing copies ofpat_first,pat_last,hf, andpred, setting up any necessary internal data structures.
The value type ofRandomIt1
must beDefaultConstructible,CopyConstructible andCopyAssignable.
For any two valuesA
andB
of the typestd::iterator_traits<RandomIt1>::value_type, ifpred(A, B)==true, thenhf(A)== hf(B) shall betrue.
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 |
Any exceptions thrown by
RandomIt1
;RandomIt1
; orBinaryPredicate
orHash
.May also throwstd::bad_alloc if additional memory required for internal data structures cannot be allocated.
template<class RandomIt2> std::pair<RandomIt2, RandomIt2> operator()( RandomIt2 first, RandomIt2 last)const; | (since C++17) | |
The member function called by the Searcher overload ofstd::search to perform a search with this searcher.RandomIt2
must meet the requirements ofLegacyRandomAccessIterator.
RandomIt1
andRandomIt2
must have the same value type.
first, last | - | a pair of iterators designating the string to be examined |
If the pattern[
pat_first,
pat_last)
is empty, returnsstd::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 bypred is located, orstd::make_pair(last, last) otherwise.
Feature-test macro | Value | Std | Feature |
---|---|---|---|
__cpp_lib_boyer_moore_searcher | 201603L | (C++17) | searchers |
#include <algorithm>#include <functional>#include <iomanip>#include <iostream>#include <string_view> int main(){constexprstd::string_view haystack="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed ""do eiusmod tempor incididunt ut labore et dolore magna aliqua"; conststd::string_view needle{"pisci"}; if(constauto it=std::search(haystack.begin(), haystack.end(), std::boyer_moore_searcher(needle.begin(), needle.end())); it!= haystack.end())std::cout<<"The string "<<std::quoted(needle)<<" found at offset "<< it- haystack.begin()<<'\n';elsestd::cout<<"The string "<<std::quoted(needle)<<" not found\n";}
Output:
The string "pisci" found at offset 43
searches for the first occurrence of a range of elements (function template)[edit] | |
(C++17) | standard C++ library search algorithm implementation (class template)[edit] |
Boyer-Moore-Horspool search algorithm implementation (class template)[edit] |