26 Containers library [containers]

26.4 Associative containers [associative]

26.4.5 Class template multimap [multimap]

26.4.5.2 multimap constructors [multimap.cons]

explicit multimap(const Compare& comp, const Allocator& = Allocator());
Effects: Constructs an empty multimap using the specified comparison object and allocator.
Complexity: Constant.
template <class InputIterator> multimap(InputIterator first, InputIterator last, const Compare& comp = Compare(), const Allocator& = Allocator());
Effects: Constructs an empty multimap using the specified comparison object and allocator, and inserts elements from the range [first, last).
Complexity: Linear in N if the range [first, last) is already sorted using comp and otherwise , where N is last - first.