Ok, I'm quite sure, I overlooked something.

First version, working

[code]
void main()
{
	auto s = S();
	auto t = T!s();
	t.fun;
}
struct S { void fun(){} }
struct T(alias s){ auto fun() { s.fun; } }
[/code]

Now, the fun method of struct T has to become static and the problems begin:
Error: static function app.main.T!(s).T.fun cannot access frame of function D main

Ok, found somewhere, that it could help to move the static function outside of the struct and tried this.

Second version, not working

[code]
void main()
{
	auto s = S();
	auto t = T!s();
	fun!(typeof(t));
}
struct S { void fun(){} }
struct T(alias s){  }
auto fun(T : T!s, alias s)() { s.fun; }
[/code]

From my point of view, the second version is the most promising one, if there are problems with the first one. However, I didn't figured it out, how to match the alias template parameter to be able to call it from within the function fun (which is now at module level) directly.

Ok. Now, trying to find a solution I wrote the third version, working

[code]
void main()
{
	auto s = S();
	auto t = T!s();
	fun(t);
}
struct S { void fun(){} }
struct T(alias s){ auto ss(){return s; } }
auto fun(T)(T t) { t.ss.fun; }
[/code]

Is this meant to be the right way? I mean, ok, if so, then, the way from different frames is a little bit verbose, but working. However, the fun method is meant to not use a specific object from the time point, where it was marked static. Why should I pass an instance to it?

On 01/23/2018 01:51 PM, Alex wrote:
> Ok, I'm quite sure, I overlooked something.
>
> First version, working
>
> [code]
> void main()
> {
>      auto s = S();
>      auto t = T!s();
>      t.fun;
> }
> struct S { void fun(){} }
> struct T(alias s){ auto fun() { s.fun; } }
> [/code]
>
> Now, the fun method of struct T has to become static and the problems
> begin:
> Error: static function app.main.T!(s).T.fun cannot access frame of
> function D main

Good news: Works at least with 2.078 as it should:

void main()
{
    auto s = S();
    auto t = T!s();
    t.fun;
}
struct S { static void fun(){} }
struct T(alias s){ auto fun() { s.fun; } }

Ali

On Tuesday, 23 January 2018 at 22:33:31 UTC, Ali Çehreli wrote:
> On 01/23/2018 01:51 PM, Alex wrote:
> > Ok, I'm quite sure, I overlooked something.
> >
> > First version, working
> >
> > [code]
> > void main()
> > {
> >      auto s = S();
> >      auto t = T!s();
> >      t.fun;
> > }
> > struct S { void fun(){} }
> > struct T(alias s){ auto fun() { s.fun; } }
> > [/code]
> >
> > Now, the fun method of struct T has to become static and the
> problems
> > begin:
> > Error: static function app.main.T!(s).T.fun cannot access
> frame of
> > function D main
>
> Good news: Works at least with 2.078 as it should:
>
> void main()
> {
>     auto s = S();
>     auto t = T!s();
>     t.fun;
> }
> struct S { static void fun(){} }
> struct T(alias s){ auto fun() { s.fun; } }
>
> Ali

the other fun is meant to be static :)
so, the fun inside T.

On 1/23/18 5:33 PM, Ali Çehreli wrote:
> On 01/23/2018 01:51 PM, Alex wrote:
>  > Ok, I'm quite sure, I overlooked something.
>  >
>  > First version, working
>  >
>  > [code]
>  > void main()
>  > {
>  >      auto s = S();
>  >      auto t = T!s();
>  >      t.fun;
>  > }
>  > struct S { void fun(){} }
>  > struct T(alias s){ auto fun() { s.fun; } }
>  > [/code]
>  >
>  > Now, the fun method of struct T has to become static and the problems
>  > begin:
>  > Error: static function app.main.T!(s).T.fun cannot access frame of
>  > function D main
> 
> Good news: Works at least with 2.078 as it should:
> 
> void main()
> {
>      auto s = S();
>      auto t = T!s();
>      t.fun;
> }
> struct S { static void fun(){} }
> struct T(alias s){ auto fun() { s.fun; } }
> 
> Ali
> 

No:

void main()
{
    auto s = S();
    auto t = T!s();
    t.fun;
}
struct S { void fun(){} }
struct T(alias s){ static fun() { s.fun; } }

Fails in 2.078.

I don't know the reason. You would think that accessing s would be relative to T.fun's stack frame, and have nothing to do with an instance of T.

I would file a bug, and see what the compiler devs say.

-Steve

On 1/23/18 5:52 PM, Steven Schveighoffer wrote:
> I don't know the reason. You would think that accessing s would be relative to T.fun's stack frame, and have nothing to do with an instance of T.
> 

using -vcg-ast gives a hint:

https://run.dlang.io/is/MZHPTY

Note that the T!(s) struct has a void *this member, that is probably the main stack frame pointer.

-Steve

On Tuesday, 23 January 2018 at 22:52:47 UTC, Steven Schveighoffer wrote:
>
> No:
>
> void main()
> {
>     auto s = S();
>     auto t = T!s();
>     t.fun;
> }
> struct S { void fun(){} }
> struct T(alias s){ static fun() { s.fun; } }
>
> Fails in 2.078.
>
> I don't know the reason. You would think that accessing s would be relative to T.fun's stack frame, and have nothing to do with an instance of T.

Right. This was the intention.

>
> I would file a bug, and see what the compiler devs say.

ok, thanks.

On Tuesday, 23 January 2018 at 22:59:31 UTC, Steven Schveighoffer wrote:
> On 1/23/18 5:52 PM, Steven Schveighoffer wrote:
>> I don't know the reason. You would think that accessing s would be relative to T.fun's stack frame, and have nothing to do with an instance of T.
>> 
>
> using -vcg-ast gives a hint:
>
> https://run.dlang.io/is/MZHPTY
>
> Note that the T!(s) struct has a void *this member, that is probably the main stack frame pointer.
>
> -Steve

So, if change the fun to static, it cannot pickup the pointer and therefore can't call anything of the aliased object. If I get it right...

cool option, by the way... didn't know anything about it. What does -ast do?

On 1/23/18 6:08 PM, Alex wrote:
> On Tuesday, 23 January 2018 at 22:59:31 UTC, Steven Schveighoffer wrote:
>> On 1/23/18 5:52 PM, Steven Schveighoffer wrote:
>>> I don't know the reason. You would think that accessing s would be relative to T.fun's stack frame, and have nothing to do with an instance of T.
>>>
>>
>> using -vcg-ast gives a hint:
>>
>> https://run.dlang.io/is/MZHPTY
>>
>> Note that the T!(s) struct has a void *this member, that is probably the main stack frame pointer.
>>
> 
> So, if change the fun to static, it cannot pickup the pointer and therefore can't call anything of the aliased object. If I get it right...

I think so. But this is a guess, as the generated call clearly never uses that 'this' member. Interesting to me that it calls that member 'this', when 'this' is already defined!

> 
> cool option, by the way... didn't know anything about it. What does -ast do?

-vcg-ast means take the generated AST before optimization (I think), and output a d-source-like file (called file.d.cg) that shows the representation. Super useful when you are trying to figure out what the compiler does to your code. It only happens if compilation succeeds.

-ast, I don't think does anything, but not sure if that's what your question was.

The reason you don't know anything about it is because it's a debugging option and not documented :) At least, that's what I was told...

If you click on the AST button on run.dlang.io, you get the same thing.

-Steve

On Tuesday, 23 January 2018 at 23:22:09 UTC, Steven Schveighoffer wrote:
>> 
>> So, if change the fun to static, it cannot pickup the pointer and therefore can't call anything of the aliased object. If I get it right...
>
> I think so. But this is a guess, as the generated call clearly never uses that 'this' member. Interesting to me that it calls that member 'this', when 'this' is already defined!
>
Hmm... yes, I see...

>> 
>> cool option, by the way... didn't know anything about it. What does -ast do?
>
> -vcg-ast means take the generated AST before optimization (I think), and output a d-source-like file (called file.d.cg) that shows the representation. Super useful when you are trying to figure out what the compiler does to your code. It only happens if compilation succeeds.
>
> -ast, I don't think does anything, but not sure if that's what your question was.
>
> The reason you don't know anything about it is because it's a debugging option and not documented :) At least, that's what I was told...
>
:)

> If you click on the AST button on run.dlang.io, you get the same thing.
>

bug filed
https://issues.dlang.org/show_bug.cgi?id=18289

Thanks a lot.