23 Containers library [containers]

23.4 Associative containers [associative]

23.4.5 Class template multimap [multimap]

23.4.5.2 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());

Requires: If the iterator's indirection operator returns an lvalue or a const rvalue pair<key_type, mapped_type>, then both key_type and mapped_type shall be CopyInsertable into *this.

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 N logN, where N is last - first.