Insert into this set the value of each value_type object in the specified range if a key equivalent to the object is not already contained in this set. The (template parameter) type RANGE must meet the requirements the C++20 standard [ranges]providing access to values of a type convertible to value_type, and value_type must be emplace-constructible from *i into this set, where i is a dereferenceable iterator obtained from range (see {Requirements on KEY}). The behavior is undefined if range overlaps this set.
Declared in <bslstl_unorderedset.h>
template<class RANGE>
void
insert_range(RANGE&& range);