unique
_ForwardIter unique(_ForwardIter __first, _ForwardIter __last) {
_ForwardIter unique(_ForwardIter __first, _ForwardIter __last,
void list<_Tp, _Alloc>::unique()
void list<_Tp, _Alloc>::unique(_BinaryPredicate __binary_pred)
void slist<_Tp,_Alloc>::unique()
void slist<_Tp,_Alloc>::unique(_BinaryPredicate __pred)