26 Containers library [containers]

26.4 Associative containers [associative]

26.4.5 Class template multimap [multimap] multimap modifiers [multimap.modifiers]

template<class P> iterator insert(P&& x); template<class P> iterator insert(const_iterator position, P&& x);
Effects: The first form is equivalent to return emplace(std​::​forward<P>(x)).
The second form is equivalent to return emplace_­hint(position, std​::​forward<P>(x)).
Remarks: These signatures shall not participate in overload resolution unless is_­constructible_­v<value_­type, P&&> is true.