libstdc++
|
The functions not1
and not2
each take a predicate functor and return an instance of unary_negate
or binary_negate
, respectively. These classes are functors whose operator()
performs the stored predicate function and then returns the negation of the result.
For example, given a vector of integers and a trivial predicate,
struct IntGreaterThanThree : public std::unary_function<int, bool> { bool operator() (int x) { return x > 3; } }; std::find_if (v.begin(), v.end(), not1(IntGreaterThanThree()));
The call to find_if
will locate the first index (i) of v
for which !(v[i] > 3)
is true.
The not1/unary_negate combination works on predicates taking a single argument. The not2/binary_negate combination works on predicates which take two arguments.
unary_negate<_Predicate> std::not1 | ( | const _Predicate & | __pred | ) | [inline] |
One of the negation functors.
Definition at line 370 of file stl_function.h.
binary_negate<_Predicate> std::not2 | ( | const _Predicate & | __pred | ) | [inline] |
One of the negation functors.
Definition at line 395 of file stl_function.h.