Luna::UnorderedSet::count

usize count(const key_type &key) const

Gets the number of elements whose key is equal to the specified key.

Parameters

• in key

  The key of the element to count.

Return value

Returns the number of elements whose key is equal to the specified key.

Remark

Since this set does not allow inserting multiple elements with the same key, the returned value will only be 1 if the key exists, or 0 if the key does not exist.