bsl::unordered_multimap::insert

Insert into this unordered multimap a value_type object created from the specified value (in constant time if the specified hint refers to an element in this container with a key equivalent to the key of value), and return an iterator referring to the newly inserted value_type object. If hint does not refer to an element in this container with a key equivalent to the key of value, 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 move‐insertable into this unordered multimap (see {Requirements on KEY and VALUE}), and the value_type be constructible from the (template parameter) ALT_VALUE_TYPE. The behavior is undefined unless hint is an iterator in the range [begin() .. end()] (both endpoints included).