Negators

Classes
class	std::unary_negate< Predicate >
	One of the negation functors. More...
class	std::binary_negate< Predicate >
	One of the negation functors. More...
Functions
template<class Predicate>
unary_negate< Predicate >	std::not1 (const Predicate &pred)
	One of the negation functors.
template<class Predicate>
binary_negate< Predicate >	std::not2 (const Predicate &pred)
	One of the negation functors.

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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.

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Function Documentation

template<class Predicate> unary_negate<Predicate> std::not1 (  const Predicate &  pred  )  [inline]

One of the negation functors. Definition at line 329 of file stl_function.h.

template<class Predicate> binary_negate<Predicate> std::not2 (  const Predicate &  pred  )  [inline]

One of the negation functors. Definition at line 355 of file stl_function.h.

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