411 REFERENCE · Wikibooks
C++ Language/Std/Stl/CollectionClasses/SortedCollections/Multiset
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
A "multiset" (an instance of class set::multiset<>) is the same as a set, except that the same item can occur multiple times.
Additional information about multiset (includes interactive examples)