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# std::set::count

From cppreference.com
< cpp‎ | container‎ | set

[edit template]

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

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`.

### [edit] Parameters

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

### [edit] Return value

Number of elements with key that compares equivalent to `key` or `x`, that is either 1 or 0.

### [edit] Complexity

Logarithmic in the size of the container.

### [edit] See also

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

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