table of contents
std::flat_map::count(3) | C++ Standard Libary | std::flat_map::count(3) |
NAME¶
std::flat_map::count - std::flat_map::count
Synopsis¶
size_type count( const Key& key ) const; (1) (since
C++23)
template< class K > (2) (since C++23)
size_type count( const K& x ) const;
Returns the number of elements with key that compares equivalent to the
specified
argument.
1) Returns the number of elements with key key. This is either 1 or 0 since
this
container does not allow duplicates.
2) Returns the number of elements with key that compares equivalent to the
value x.
This overload participates in overload resolution only if the qualified-id
Compare::is_transparent is valid and denotes a type. It allows 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, for
overload (1), is either 1 or 0.
Complexity¶
Logarithmic in the size of the container plus linear in the
number of elements
found.
Example¶
This section is incomplete
Reason: no example
See also¶
find finds element with specific key
(public member function)
equal_range returns range of elements matching a specific key
(public member function)
Category:¶
* Todo no example
2024.06.10 | http://cppreference.com |