24.7 Standard Function Objects, Predicates, and Binders (cont.)

negator - another category of binder
not1 takes a unary predicate, inverts the result
not2 takes a binary predicate, inverts the result
E.g., find the first non-negative number:
list<int>::iterator first_positive = find_if( a.begin(), a.end(), not1( bind2nd( less<int>(), 0 )) );