std::multimap<Key,T,Compare,Allocator>::value_compare (3) - Linux Manuals

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


std::multimap<Key,T,Compare,Allocator>::value_compare - std::multimap<Key,T,Compare,Allocator>::value_compare


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 (until C++20)
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

Protected member objects

             the stored comparator
Compare comp (protected member object)

Member functions

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


value_compare( Compare c );

Initializes the internal instance of the comparator to c.


c - comparator to assign


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

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


lhs, rhs - values to compare

Return value

comp(lhs.first, rhs.first).