Pointers to methods

[Ali Çehreli]

On 03/03/2013 07:21 PM, nazriel wrote:

 > *[1] - code for lazy people :

Thank you very much for doing that. It is the only way to ensure that 
these threads will remain complete.

Here are two ways depending on what you need:

import std.stdio;

class A
{
     int x;

public:
     this (int y) { x = y; }

     void foo()
     {
         writefln("::foo(), x: %s", x);
     }
};

class B : A
{
public:
     this(int y)
     { super(y); }
};

void main()
{
     {
         auto a = new A(3);
         auto b = new B(4);

         // When objects are available up front, initialize the function
         // pointer by an object:
         auto fp = &a.foo;
         fp();
         fp = &b.foo;
         fp();
     }

     {
         // When no object is available up front, use a function literal 
to be
         // called with objects later on:
         auto fp = ((A o) => o.foo());

         auto a = new A(5);
         auto b = new B(6);

         fp(a);
         fp(b);
     }
}

Ali