Negators
Utilities » Function Objects
Collaboration diagram for Negators:

## Classes

class | std::binary_negate< _Predicate >
class | std::unary_negate< _Predicate >

## Functions

template<typename _Predicate >
_GLIBCXX14_CONSTEXPR unary_negate< _Predicate > | std::not1 (const _Predicate &__pred)
template<typename _Predicate >
_GLIBCXX14_CONSTEXPR binary_negate< _Predicate > | std::not2 (const _Predicate &__pred)

## Detailed Description

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.

## Function Documentation

## not1()

template<typename _Predicate >

_GLIBCXX14_CONSTEXPR unary_negate<_Predicate> std::not1 | ( | const _Predicate & | __pred | ) |

inline

One of the negation functors.

Definition at line 1000 of file stl_function.h.

## not2()

template<typename _Predicate >

_GLIBCXX14_CONSTEXPR binary_negate<_Predicate> std::not2 | ( | const _Predicate & | __pred | ) |

inline

One of the negation functors.

Definition at line 1028 of file stl_function.h.