std::default_searcher, std::make_default_searcher

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Utilities library

Type support (basic types, RTTI, type traits)

Dynamic memory management

Error handling

Program utilities

Variadic functions

Date and time

Function objects

initializer_list (C++11)

bitset

hash (C++11)

Relational operators

rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>=

Optional and any

optional (C++17)

any (C++17)

Pairs and tuples

pair

tuple (C++11)

apply (C++17)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

integer_sequence (C++14)

Swap, forward and move

swap

exchange (C++14)

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

Type operations

declval (C++11)

as_const (C++17)

 

Function objects

Function wrappers
function (C++11)
mem_fn (C++11)
bad_function_call (C++11)
invoke (C++17)
Bind
bind (C++11)
is_bind_expression (C++11)
is_placeholder (C++11)
_1, _2, _3, ... (C++11)
Reference wrappers
reference_wrapper (C++11)
refcref (C++11)(C++11)
Operator wrappers
plus minus negate multiplies divides modulus logical_and logical_or logical_not	equal_to not_equal_to greater less greater_equal less_equal bit_and bit_or bit_xor bit_not (C++14)
Negators
not_fn not1 (deprecated) not2 (deprecated)	unary_negate (deprecated) binary_negate (deprecated)
Searchers
default_searcher (C++17) boyer_moore_searcher (C++17) boyer_moore_horspool_searcher (C++17)	make_default_searcher (C++17) make_boyer_moore_searcher (C++17) make_boyer_moore_horspool_searcher (C++17)
Old binders and adaptors
unary_function (until C++17)
binary_function (until C++17)
ptr_fun (until C++17)
pointer_to_unary_function (until C++17)
pointer_to_binary_function (until C++17)
mem_fun (until C++17)
mem_fun_tmem_fun1_tconst_mem_fun_tconst_mem_fun1_t (until C++17)(until C++17)(until C++17)(until C++17)
mem_fun_ref (until C++17)
mem_fun_ref_tmem_fun1_ref_tconst_mem_fun_ref_tconst_mem_fun1_ref_t (until C++17)(until C++17)(until C++17)(until C++17)
binder1stbinder2nd (until C++17)(until C++17)
bind1stbind2nd (until C++17)(until C++17)

 

Defined in header <functional>
template< class ForwardIterator1, class BinaryPredicate = std::equal_to<> > class default_searcher;		(since C++17)

A class suitable for use with Searcher overload of std::search that delegates the search operation to the pre-C++17 standard library's std::search.

default_searcher is CopyConstructible and CopyAssignable.

Member functions

std::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::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 the Searcher overload of std::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());		(since C++17)

Helper function that constructs a std::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 <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_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)