Insert into this multimap a newly-created value_type object, constructed by forwarding get_allocator() (if required) and the specified (variable number of) args to the corresponding constructor of value_type (in amortized constant time if the specified hint is a valid immediate successor to the value_type object constructed from args). Return an iterator referring to the newly created and inserted object in this multimap. If hint is not a valid immediate successor to the value_type object implied by args, this operation has O[log(N)] complexity where N is the size of this multimap. This method requires that the (template parameter) types KEY and VALUE both be emplace-constructible from args (see {Requirements on KEY and VALUE}). The behavior is undefined unless hint is an iterator in the range [begin() .. end()] (both endpoints included).
Declared in <bslstl_multimap.h>
template<class... Args>
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
emplace_hint(
const_iterator hint,
Args&&... args);