std::set<Key,Compare,Allocator>::count (3) - Linux Man Pages

std::set<Key,Compare,Allocator>::count: std::set<Key,Compare,Allocator>::count

NAME

std::set<Key,Compare,Allocator>::count - std::set<Key,Compare,Allocator>::count

Synopsis


size_type count( const Key& key ) const; (1)
template< class K > (2) (since C++14)
size_type count( const K& x ) const;


Returns the number of elements with key that compares equivalent to the specified argument, which is either 1 or 0 since this container does not allow duplicates.
1) Returns the number of elements with key key.
2) Returns the number of elements with key that compares equivalent to the value x. This overload only participates in overload resolution if the qualified-id Compare::is_transparent is valid and denotes a type. They allow calling this function without constructing an instance of Key.

Parameters


key - key value of the elements to count
x - alternative value to compare to the keys

Return value


Number of elements with key that compares equivalent to key or x, which is either 1 or 0 for (1).

Complexity


Logarithmic in the size of the container.

See also


            finds element with specific key
find (public member function)
            returns range of elements matching a specific key
equal_range (public member function)