23 Containers library [containers]

23.5 Unordered associative containers [unord]

23.5.5 Class template unordered_multimap [unord.multimap]

23.5.5.2 unordered_multimap constructors [unord.multimap.cnstr]

explicit unordered_multimap(size_type n = see below, const hasher& hf = hasher(), const key_equal& eql = key_equal(), const allocator_type& a = allocator_type());

1

Effects: Constructs an empty unordered_multimap using the specified hash function, key equality function, and allocator, and using at least n buckets. If n is not provided, the number of buckets is implementation-defined. max_load_factor() returns 1.0.

2

Complexity: Constant.

template <class InputIterator> unordered_multimap(InputIterator f, InputIterator l, size_type n = see below, const hasher& hf = hasher(), const key_equal& eql = key_equal(), const allocator_type& a = allocator_type());

3

Effects: Constructs an empty unordered_multimap using the specified hash function, key equality function, and allocator, and using at least n buckets. If n is not provided, the number of buckets is implementation-defined. Then inserts elements from the range [f, l). max_load_factor() returns 1.0.

4

Complexity: Average case linear, worst case quadratic.