logical_not

Module:  Standard C++ Library   Library:  General utilities

Does not inherit

• Local Index
• Summary
• Synopsis
• Description
• Interface
• See Also
• Standards Conformance

A unary function object that returns true if its argument is false

#include <functional>

namespace std {
  template <class T>
  struct logical_not;
}

logical_not is a unary function object. Its operator() returns true if its argument is false. You can pass a logical_not object to any algorithm that requires a unary function. For example, the replace_if() algorithm replaces an element with another value if the result of a unary operation is true. logical_not is used in that algorithm in the following manner:

vector<int> vec1;
.
.
.
void replace_if(vec1.begin(), vec1.end(),
                logical_not<int>(),1);

This call to replace_if() replaces all zeros in the vec1 with 1.

namespace std {

  template <class T>
  struct logical_not : unary_function<T, bool> {
    bool operator() (const T&) const;
  };
}

Function Objects, unary_function

ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 20.3.4

Copyright (c) 1994-2006 Rogue Wave Software, a Quovadx Division.
Licensed under the Apache License, Version 2.0.
Contact Rogue Wave about documentation or support issues. You can also seek help from other developers through the Apache stdcxx community (see below).