cpp/container/unordered multiset/insert

Inserts element(s) into the container.

@1-2@ Inserts.

@3-4@ Inserts, using as a non-binding suggestion to where the search should start.

@5@ Inserts elements from range.

@6@ Inserts elements from initializer list.

Return value
@1-4@ Returns an iterator to the inserted element.

@5-6@ (none)

Exceptions
@1-4@ If an exception is thrown by any operation, the insertion has no effect.

Complexity
@1-4@ Average case:, worst case

@5-6@ Average case:, where N is the number of elements to insert. Worse case:

@7-8@ Average case:, worst case