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

C++

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Named requirements

Language support library

Concepts library (C++20)

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Regular expressions library (C++11)

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Technical Specifications

Technical specifications

Filesystem library (filesystem TS)

Library fundamentals (library fundamentals TS)

Library fundamentals 2 (library fundamentals 2 TS)

Extensions for parallelism (parallelism TS)

Extensions for parallelism 2 (parallelism TS v2)

Extensions for concurrency (concurrency TS)

Concepts (concepts TS)

Ranges (ranges TS)

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Library fundamentals

experimental::optional

experimental::any

experimental::basic_string_view

experimental::sample

experimental::shared_ptr

experimental::weak_ptr

experimental::apply

experimental::invocation_type experimental::raw_invocation_type

experimental::search

experimental::default_searcher experimental::make_default_searcher

experimental::boyer_moore_searcher experimental::make_boyer_moore_searcher

experimental::boyer_moore_horspool_searcher experimental::make_boyer_moore_horspool_searcher

type-erased and polymorphic allocators

variable templates for type traits

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.

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)

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);

Parameters

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

Return value

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

Example

Run this code

#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

See also

search

searches for a range of elements (function template)