21 Containers library [containers]

21.4 Associative containers [associative]

21.4.5 Class template multimap [multimap]

21.4.5.3 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.