Standard C++ LibraryCopyright 1996, Rogue Wave Software, Inc.

NAME

  logical_or  - Binary function object that returns true if either of its
  arguments are true.

SYNOPSIS

  #include <functional>

  template <class T>
  struct logical_or : binary_function<T, T, bool> ;

DESCRIPTION

  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:

  vector<bool> vec1;
  vector<bool> vec2;
  vector<bool> vecResult;
  transform(vec1.begin(), vec1.end(),
           vec2.begin(),
           vecResult.begin(), logical_or<bool>());

  After this call to transform, vecResult(n) will contain a "1" (true) if
  either vec1(n) or vec2(n) is true or a "0" (false) if both vec1(n) and
  vec2(n) are false.

INTERFACE

  template <class T>
  struct logical_or : binary_function<T, T, bool> {
   typedef typename binary_function<T, T, bool>::second_argument_type
                                                 second_argument_type;
   typedef typename binary_function<T, T, bool>::first_argument_type
                                                 first_argument_type;
   typedef typename binary_function<T, T, bool>::result_type
                                                 result_type;
   bool operator() (const T&, const T&) const;
  };

WARNING

  If your compiler does not support default template parameters, you will
  need to always supply the Allocator template argument.  For instance, you
  will have to write :

  vector<bool, allocator<bool> >

  instead of:

  vector<bool>

SEE ALSO

  binary_function, function objects

STANDARDS CONFORMANCE

  ANSI X3J16/ISO WG21 Joint C++ Committee



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