betterC shared static ctor

[vit]

On Wednesday, 21 July 2021 at 08:28:22 UTC, Mike Parker wrote:
> On Wednesday, 21 July 2021 at 08:11:06 UTC, vit wrote:
>> Is it possible to call all shared static ctors in betterC?
>>
>> ```d
>> //-betterC
>>
>> static immutable int i;
>>
>> shared static this(){
>> 	i = 42;
>> }
>> extern(C) void main(){
>>     assert(i != 42);
>>
>> }
>> ```
>
> These rely on DRuntime, which is not linked in betterC mode. 
> You'll need to use the `crt_constructor` and `crt_destructor` 
> pragmas:
>
> https://dlang.org/spec/pragma.html#crtctor
>
> Apply them to any `extern(C) function for static ctor/dtor 
> behavior.

Thanks, it works, but now I have different problem.
I need call static method for all instantions of template struct 
from `crt_constructor`.
Is there way to iterate over all instantions of template?

I need this to work but for all instantions of Foo, not only for 
Foo!1 a Foo!2


https://run.dlang.io/is/FNqHWh :
```d
pragma(crt_constructor)
extern(C)void shared_static_this(){
     Foo!1.vtable_init();
     Foo!2.vtable_init();
     //Foo!3.vtable_init();
}

extern(C) void main(){
     auto foo1 = Foo!1(null);
     auto foo2 = Foo!2(null);
     auto foo3 = Foo!3(null);

     Base* b1 = &foo1.base;
     Base* b2 = &foo2.base;
     Base* b3 = &foo3.base;
     assert(b1.getId() == 1);
     assert(b2.getId() == 2);
     //assert(b3.getId() == 3);	//vtable is not initialized

}

struct Vtable{
     size_t offset;
	size_t function(void* ) getId;
}
struct Base{
     immutable Vtable* vptr;

     this(immutable Vtable* vptr){
         assert(vptr !is null);
     	this.vptr = vptr;
     }

     size_t getId(){
     	return vptr.getId((cast(void*)&this) - vptr.offset);
     }
}

struct Foo(size_t id){
     static immutable Vtable vtable;
Base base;


     this(typeof(null) nil){
         this.base = Base(&vtable);
     }

     static size_t virtual_getId(Foo* foo){
     	return id;
     }

     static void vtable_init(){
     	Vtable* vtable = cast(Vtable*)&vtable;
         vtable.offset = base.offsetof;
         vtable.getId = cast(typeof(Vtable.getId))&virtual_getId;
     }
}

```