I have a c++ struct:

template <typename retval>
struct ezDelegate<retval ()>
{
}

void DelegateTest(ezDelegate<void ()> func) { ... }

And I want to match that on the D side, unfortunately it does not work:

D:
struct ezDelegate(Signature) {}

alias delegate_t = ezDelegate!(void function());

extern(C++) void DelegateTest(delegate func);

D mangles
?DelegateTest@@YAXU?$ezDelegate@$$A6AXXZ@@@Z
void __cdecl DelegateTest(struct ezDelegate<void (__cdecl*)(void)>)

What C++ does:
?DelegateTest@@YAXU?$ezDelegate@P6AXXZ@@@Z
void __cdecl DelegateTest(struct ezDelegate<void __cdecl(void)>)

I understand that "void function()" is actually a function pointer and thus the mangling is "correct". But in what way would you actually able to mirror the C++ declaration of ezDelegate? Does it even work? This would be a central part of my interop with C++ so making it work would be nice.

Kind Regards
Benjamin Thaut

"Benjamin Thaut"  wrote in message news:mbtena$2n46$1@digitalmars.com... 

> I understand that "void function()" is actually a function pointer and thus the mangling is "correct". But in what way would you actually able to mirror the C++ declaration of ezDelegate? Does it even work? This would be a central part of my interop with C++ so making it work would be nice.

struct X(T) { pragma(msg, X.stringof); }

void main()
{
   X!(typeof(*(void function()).init)) x;
}

Am 17.02.2015 um 02:21 schrieb Daniel Murphy:
>
> struct X(T) { pragma(msg, X.stringof); }
>
> void main()
> {
>     X!(typeof(*(void function()).init)) x;
> }
>

Error: ICE: Unsupported type void()

So close...

"Benjamin Thaut"  wrote in message news:mbuok2$pn5$1@digitalmars.com...

> Error: ICE: Unsupported type void()
>
> So close...

Good news is that that's a compiler bug and not a language limitation. Although allowing you to pass a function type to a template in the first place might also be a compiler bug.

D/C++ interop really works best when you can massage the C++ side a little. 

On 2/16/2015 10:54 PM, Benjamin Thaut wrote:
> Am 17.02.2015 um 02:21 schrieb Daniel Murphy:
>>
>> struct X(T) { pragma(msg, X.stringof); }
>>
>> void main()
>> {
>>     X!(typeof(*(void function()).init)) x;
>> }
>>
>
> Error: ICE: Unsupported type void()
>
> So close...

Please file bugzilla!

On 2/16/2015 11:42 PM, Daniel Murphy wrote:
> "Benjamin Thaut"  wrote in message news:mbuok2$pn5$1@digitalmars.com...
>
>> Error: ICE: Unsupported type void()
>>
>> So close...
>
> Good news is that that's a compiler bug and not a language limitation. Although
> allowing you to pass a function type to a template in the first place might also
> be a compiler bug.
>
> D/C++ interop really works best when you can massage the C++ side a little.

True, it might be easier to adjust the C++ side so it takes a pointer to a function type.

On Tuesday, 17 February 2015 at 08:16:37 UTC, Walter Bright wrote:
>
> True, it might be easier to adjust the C++ side so it takes a pointer to a function type.

In this case it would be really ugly

ezDelegate<void()> vs ezDelegate<void(*)()>

I will do a pull request later today fixing this mangling issue.

Am 17.02.2015 um 09:13 schrieb Walter Bright:
> On 2/16/2015 10:54 PM, Benjamin Thaut wrote:
>> Am 17.02.2015 um 02:21 schrieb Daniel Murphy:
>>>
>>> struct X(T) { pragma(msg, X.stringof); }
>>>
>>> void main()
>>> {
>>>     X!(typeof(*(void function()).init)) x;
>>> }
>>>
>>
>> Error: ICE: Unsupported type void()
>>
>> So close...
>
> Please file bugzilla!

https://issues.dlang.org/show_bug.cgi?id=14195
https://github.com/D-Programming-Language/dmd/pull/4419

On 2/17/2015 11:25 AM, Benjamin Thaut wrote:
> Am 17.02.2015 um 09:13 schrieb Walter Bright:
>> Please file bugzilla!
>
> https://issues.dlang.org/show_bug.cgi?id=14195
> https://github.com/D-Programming-Language/dmd/pull/4419

Thank you