std::multimap::value_compare

 

C++

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Technical Specifications

 

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

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span (C++20)

 

std::multimap

Member functions

multimap::multimap

multimap::~multimap

multimap::operator=

multimap::get_allocator

Iterators

multimap::beginmultimap::cbegin (C++11)

multimap::endmultimap::cend (C++11)

multimap::rbeginmultimap::crbegin (C++11)

multimap::rendmultimap::crend (C++11)

Capacity

multimap::erase

multimap::size

multimap::max_size

Modifiers

multimap::clear

multimap::insert

multimap::emplace (C++11)

multimap::emplace_hint (C++11)

multimap::erase

multimap::swap

multimap::extract (C++17)

multimap::merge (C++17)

Lookup

multimap::count

multimap::find

multimap::contains (C++20)

multimap::equal_range

multimap::lower_bound

multimap::upper_bound

Observers

multimap::key_comp

multimap::value_comp

Deduction guides(C++17)

 

class value_compare;

std::multimap::value_compare is a function object that compares objects of type std::multimap::value_type (key-value pairs) by comparing of the first components of the pairs.

Member types Type Definition result_type(deprecated in C++17) bool first_argument_type(deprecated in C++17) value_type second_argument_type(deprecated in C++17) value_type

(until C++20)

Protected member objects

Compare comp

the stored comparator (protected member object)

Member functions

(constructor)	constructs a new value_compare object (protected member function)
operator()	compares two values of type value_type (public member function)

std::multimap<Key,T,Compare,Alloc>::value_compare::value_compare

protected: value_compare( Compare c );

Initializes the internal instance of the comparator to c.

Parameters

c

-

comparator to assign

std::multimap<Key,T,Compare,Alloc>::value_compare::operator()

bool operator()( const value_type& lhs, const value_type& rhs ) const;

Compares lhs.first and rhs.first by calling the stored comparator.

Parameters

lhs, rhs

-

values to compare

Return value

comp(lhs.first, rhs.first).

Exceptions

(none)