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# std::unordered_set::count

From cppreference.com
< cpp‎ | container‎ | unordered set

[edit template]

size_type count( const Key& key ) const; | (1) | (since C++11)

Returns the number of elements with key that compares equal to the specified argument `key`, which is either 1 or 0 since this container does not allow duplicates.

### [edit] Parameters

key | - | key value of the elements to count

### [edit] Return value

Number of elements with key `key`, that is either 1 or 0.

### [edit] Complexity

Constant on average, worst case linear 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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