bound pointer to member

[Jonathan Wakely]

On 23 February 2011 10:19, Klaus Rudolph wrote:
> Hi,
>
> I search for a simple code snipped which shows how bound pointers work.
> I always end up in the message :
>
> main.cpp:51: error: ISO C++ forbids taking the address of a bound member function to form a pointer to member function.  Say ‘&A::Func2’
>
> Can anyone post a code snippet which compiles on g++?

$ cat bound.cc
struct Sq {
  int f(int i) { return i*i; }
};

int main()
{
  typedef int (*funcptr_type)(Sq*, int);

  funcptr_type f = (funcptr_type)(&Sq::f);

  Sq sq;

  return f(&sq, 4);
}
$ g++ bound.cc -Wno-pmf-conversions
$ ./a.out ; echo $?
16
$


>Is there a need to give any special options to enable this language extension?

As stated in the manual, use -Wno-pmf-conversions to suppress a
warning, but it still works even if the warning is issued.

http://gcc.gnu.org/onlinedocs/gcc/Bound-member-functions.html