PRODUCT  :  Borland C++                           NUMBER  :  1152
  VERSION  :  3.1
       OS  :  ALL
     DATE  :  October 19, 1993                         PAGE  :  1/2

    TITLE  :  Example of function returning pointer to function.





  This is an example demonstrating a function that returns a
  pointer to a function.

  /*
       This is an example demonstrating a function
       that returns a pointer to a function.

       Expected output should be

       in bar()
       A comes before B
  */

  #include <stdio.h>

  /*
       funcptr is a pointer to a function that
       takes a single argument of type char and returns
       nothing.
  */

  typedef void (*funcptr)( char );

  /*
       foo is a function takes a single argument of type char
       and returns nothing.
  */

  void foo( char letter )
  {
       printf( "%c comes before %c\n", letter, letter + 1 );
  }

  /*
       bar is a function that takes no arguments and returns
       a pointer to a function that takes a single argument
       of type char and returns nothing.
  */

  funcptr bar( void )
  {
       printf( "in bar()\n" );













  PRODUCT  :  Borland C++                           NUMBER  :  1152
  VERSION  :  3.1
       OS  :  ALL
     DATE  :  October 19, 1993                         PAGE  :  2/2

    TITLE  :  Example of function returning pointer to function.




       return foo;
  }

  void main( void )
  {
  /*
       Line B below is equivalent to:
            void (*f)(char) = bar();
      Thus, f is a pointer to a function X that takes one argument
      of type char and X returns a pointer to a function of type
      void (*)(int).  Note that f doesn't point to the function
      bar(); it points to what bar() returns.
  */
      /*  Line A is equivalent to Line B */

      /*  void (*f)(char) = bar(); */    /* Line A */
      funcptr f = bar();                 /* Line B */
  /*
      Now call the function that f points to.  Since f points to
      function foo(), which takes a single argument of type char,
      we want to pass it a single char argument.
  */
      f('A');
  }



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