C++ Macro to D mixin template, delegates Please help

[BLS]

Regan Heath schrieb:
> BLS wrote:
>> Regan Heath schrieb:
>>> Henning Hasemann wrote:
> 
> I don't understand.  What doesn't the code Henning posted do, that you 
> need it to do??
> 

Probabely, because I am not genius... :-( I 'd better read it twice! 
Just one question : It seems that you use template overloading, or do I 
miss something. In other words : Can I use template overloading like 
function overloading ?

Many thanks for your efforts, Regan and Henning !
Bjoern


> class Foo {
>   void foo() {
>     writefln("foo called");
>   }
>   void bar() {
>     writefln("bar called");
>   }
> 
>   mixin MessageMap!(
>     OnClose!(foo),
>     OnRange!(1, 3, bar)
>   );
> }
> 
> expands to:
> 
> class Foo {
>   void foo() {
>     writefln("foo called");
>   }
>   void bar() {
>     writefln("bar called");
>   }
> 
>   void newMsgProc(uint uID) {      //expands just like "BEGIN_MSG_MAP"
>      foreach(mapping; Mappings) {  //loops 2x
>        if(mapping.matches(uID))    //just like "if (uID == WM_CLOSE)"
>          mapping.executeAction();  //just like "vfunc();"
>      }
>   }
> }
> 
> Change MessageMap to expand to the function fignature you want, i.e.
> 
> template MessageMap(Mappings ...) {
>   override BOOL NewMsgProc(HWND hWnd, UINT uID, WPARAM wParam, LPARAM 
> lParam, ref LRESULT lResult) {
>      foreach(mapping; Mappings) {
>        if(mapping.matches(uID))
>          mapping.executeAction();
>      }
>   }
> }
> 
> Change MessageMap to return the result of the mapping.executeAction just 
> like "return lResult;" in the original C++.
> 
> template MessageMap(Mappings ...) {
>   override BOOL NewMsgProc(HWND hWnd, UINT uID, WPARAM wParam, LPARAM 
> lParam, ref LRESULT lResult) {
>      foreach(mapping; Mappings) {
>        if(mapping.matches(uID)) {
>          lResult = mapping.executeAction();
>          return cast(BOOL)lResult;
>        }
>      }
>   }
> }
> 
> I think it's ok to use mixins as you're desribing, but why do you need 
> to do it that way?
> 
> Regan

Probabely, because I am not genius... :-( I 'd better read it twice! 
Just one question : It seems that you use template overloading, or do I 
miss something. In other words is template overloading legal ?

Many thanks for your efforts, Regan and Henning !
Bjoern