Functors

[Craig Black]

Very useful hack.  Thanks!

"BCS" <ao at pathlink.com> wrote in message 
news:ce0a3343b7368c987a5d27c1f2e at news.digitalmars.com...
> Reply to Craig,
>
>>> if all you want to do is convert fn ptrs to delegates this works:
>>>
>>> |T delegate(A) Fn2Dg(T, A...)(T function(A) f)
>>> |{
>>> | struct tmp
>>> | {
>>> | T ret(A args){ return (cast(T function(A))this)(args); }
>>> | };
>>> | return &(cast(tmp*)f).ret;
>>> |}
>> I didn't know this was possible.  Are you sure this works? I thought
>> there were some issues with calling conventions.
>>
>> -Craig
>>
>
> What goes on there is that the context pointer (which is supposed to be a 
> object, struct or stack frame) is in fact a function pointer. The calling 
> convention for delegates never actually de references the context pointer 
> so what is is doesn't matter. In this case I convert it back to a function 
> pointer, and then call it with the arguments I was given. All of the 
> values in the arguments get copied and arranged correctly for the function 
> call and everything is fine and dandy.
>
>