std::boyer_moore_searcher, std::make_boyer_moore_searcher
| Defined in header
<functional>
|
||
| template< class RandomIt1,
class Hash = std::hash<typename std::iterator_traits<RandomIt1>::value_type>, |
(since C++17) | |
A searcher suitable for use with the Searcher overload of std::search that implements the Boyer-Moore string searching algorithm.
boyer_moore_searcher is CopyConstructible and CopyAssignable.
RandomIt1 must meet the requirements of RandomAccessIterator.
Contents |
[edit] Member functions
std::boyer_moore_searcher::boyer_moore_searcher
| boyer_moore_searcher( RandomIt1 pat_first,
RandomIt1 pat_last, |
||
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
BinaryPredicateorHash.
May also throw std::bad_alloc if additional memory required for internal data structures cannot be allocated.
std::boyer_moore_searcher::operator()
| template< class RandomIt2 >
std::pair<RandomIt2,RandomIt2> operator()( RandomIt2 first, RandomIt2 last ) const; |
(since C++17) | |
The member function called by the Searcher overload of std::search to perform a search with this searcher. RandomIt2 must meet the requirements of RandomAccessIterator.
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 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.
[edit] Helper Functions
| template< class RandomIt,
class Hash = std::hash<typename std::iterator_traits<RandomIt>::value_type>, |
||
Helper function that constructs a std::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 <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::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 a range of elements (function template) |