bsl::unordered_multimap::emplace_hint

Insert into this unordered 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 constant time if the specified hint refers to an element in this container with a key equivalent to the key of the newly created value_type object), and return an iterator referring to the newly created and inserted object. If hint does not refer to an element in this container with a key equivalent to the key of the newly created value_type object, this operation has worst case O[N] and average case constant‐time complexity, where N is the size of this unordered 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).