logical_or

Library:  General utilities

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A binary function object that returns true if either of its arguments are true

#include <functional>

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

logical_or is a binary function object. Its operator() returns true if either x or y are true. You can pass a logical_or object to any algorithm that requires a binary function. For example, the transform() algorithm applies a binary operation to corresponding values in two collections and stores the result of the function. logical_or is used in that algorithm in the following manner:

list<bool> list1;
list<bool> list2;
list<bool> listResult;
.
.
.
transform(list1.begin(), list1.end(),
          list2.begin(),
          listResult.begin(), logical_or<bool>());

After this call to transform(), listResult(n) contains a 1 (true) if either list1(n) or list2(n) is true, or a 0 (false) if both list1(n) and list2(n) are false.

namespace std {

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

binary_function, Function Objects

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