Re: function pointers

From:

Carl Barron <cbarron413@adelphia.net>

Newsgroups:

comp.lang.c++.moderated

Date:

Wed, 20 Jun 2007 09:29:21 CST

Message-ID:

<190620072147412613%cbarron413@adelphia.net>

In article <1182283434.863580.316930@g4g2000hsf.googlegroups.com>,
ender <astrothayne@gmail.com> wrote:

why can't the new operator be used on function pointers?

Can you post an example of what you are trying to do?

maybe I have the syntax wrong but when I tried creating a vector of
the form vector< int (*)(window, unsigned int)> I got a compile time
error stating that new could not be used on int (*)(window, unsigned
int). perhaps I am just ignorent of the correct way to pass a
function pointer type as a template argument (or use it in a
typedef). If that is the cause could you tell me the correct syntax?

try this it should produce 0 1 2 3 on separate lines:
#include <vector>
#include <iostream>
#include <algorithm>

typedef int (*PF)(int);

int foo(int x) { return x;}

struct bar
{
   int x;
   bar():x(0){}
   void operator () (PF f)
   {
      std::cout << f(x++) << '\n';
   }
};

int main()
{
   std::vector<PF> vec;
   for(int i=0;i!=4;++i)
      vec.push_back(foo);
   std::for_each(vec.begin(),vec.end(),bar());
}

--
      [ See http://www.gotw.ca/resources/clcm.htm for info about ]
      [ comp.lang.c++.moderated. First time posters: Do this! ]