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

NAME

  less  - Binary function object that returns true if its first argument is
  less than its second

SYNOPSIS

  #include<functional>

  template <class T>
  struct less : public binary_function<T, T, bool> ;

DESCRIPTION

  less is a binary function object.  Its operator() returns true if x is less
  than y.  You can pass a less 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.   less would be used in that algorithm in the following manner:

  vector<int> vec1;
  vector<int> vec2;
  vector<int> vecResult;
  transform(vec1.begin(), vec1.end(),
           vec2.begin(),
           vecResult.begin(), less<int>());

  After this call to transform, vecResult(n) will contain a "1" if vec1(n)
  was less than  vec2(n) or a "0" if vec1(n) was greater than or equal to
  vec2(n).

INTERFACE

  template <class T>
  struct less : 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, then you
  need to always supply the Allocator template argument.  For instance,
  you'll have to write :

  vector<int, allocator<int> >

  instead of

  vector<int>

SEE ALSO

  binary_function, function objects

STANDARDS CONFORMANCE

  ANSI X3J16/ISO WG21 Joint C++ Committee



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