BloombergLP::bdlc::FlatHashSet::equal_range

Return a pair of const_iterator`s defining the sequence of elements in this set having the specified `key, where the first iterator is positioned at the start of the sequence and the second iterator is positioned one past the end of the sequence. If this set contains no KEY elements equivalent to key, then the two returned iterators will have the same value. Note that since a set maintains unique keys, the range will contain at most one element.