Function name as text

[Bill Baxter]

Craig Black wrote:
> I have been considering porting some C++ code to D.  One of the classes I 
> would have to port is an event queue class where each event on the queue has 
> a delegate and a text string that points to the function name that the 
> delegate refers to.  The function name is used to visualize the event queue 
> for run-time debugging purposes.  It is important to capture both the class 
> name and the function name as text.
> 
> In C++ I had a macro called DISPATCH that used the stringize operator # to 
> capture the name of the function.  The good (and bad) thing about C++ in 
> this case is that when specifying a pointer to a member, you must fully 
> qualify the function name, so you would have something like this.
> 
> class Foo {
> public:
>   void bar() {}
> };
> 
> Foo *foo = new Foo;
> Event event = DISPATCH(foo, &Foo::bar);
> 
> Using the stringize operator, the DISPATCH macro could capture the text 
> string "Foo::bar" as well as the member function pointer.  Here is the 
> equivalent code in D..
> 
> Foo foo = new Foo;
> Event event = dispatch(&foo.bar);
> 
> Which is much more elegant, except that I can't figure out a way to capture 
> the name of the function and it's class.  I tried fiddling with the stringof 
> operator but that doesn't seem to work.
> 
> Any ideas? 

There probably isn't a way to do it right now without using a string 
mixin, which uglies things up on the calling side:

      Event event = mixin(dispatch("&foo.bar"));

Macros are supposed to give us a way to clean that up.  But for now 
you're probably better off just passing the name separately like 
dispatch(&foo.bar, "foo");

--bb