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std::experimental::default_searcher, std::experimental::make_default_searcher

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Defined in header <experimental/functional>
template< class ForwardIterator1, class BinaryPredicate = std::equal_to<> >
class default_searcher;
(library fundamentals TS)

A class suitable for use with std::experimental::search that delegates the search operation to the standard library's std::search.

default_searcher is CopyConstructible and CopyAssignable.

Contents

[edit] Member functions

std::experimental::default_searcher::default_searcher

default_searcher( ForwardIterator pat_first,

                  ForwardIterator pat_last,

                  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 ForwardIterator.

std::experimental::default_searcher::operator()

template< class ForwardIterator2 >
ForwardIterator2 operator()( ForwardIterator2 first, ForwardIterator2 last ) const;
(until C++17)
template< class ForwardIterator2 >

std::pair<ForwardIterator2, ForwardIterator2>

    operator()( ForwardIterator2 first, ForwardIterator2 last ) const;
(since C++17)

The member function called by std::experimental::search to perform a search with this searcher.

Equivalent to std::search(first, last, pat_first, pat_last, pred);

(until C++17)

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

(until C++17)

Parameters

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

Return value

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)

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.

(since C++17)


[edit] Helper Functions

template< class ForwardIterator, class BinaryPredicate = std::equal_to<> >

default_searcher<ForwardIterator, BinaryPredicate> make_default_searcher(
    ForwardIterator pat_first,
    ForwardIterator pat_last,

    BinaryPredicate pred = BinaryPredicate());
(library fundamentals TS)

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

[edit] Parameters

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

[edit] Return value

A default_searcher constructed with the arguments pat_first, pat_last, pred.

[edit] Example

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

[edit] See also

searches for a range of elements
(function template) [edit]