Re: betterC shared static ctor

[Steven Schveighoffer via Digitalmars-d-learn]

On 7/21/21 5:07 AM, vit wrote:


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?


Not unless you register them somehow upon instantiation.

Or (I think) you can implement the constructor as a static method, and 
tag it with `pragma(crt_constructor)`. Then it gets added when instantiated.


-Steve

Re: betterC shared static ctor

[vit via Digitalmars-d-learn]

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;
}
}

```

Re: betterC shared static ctor

[Mike Parker via Digitalmars-d-learn]

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.

betterC shared static ctor

[vit via Digitalmars-d-learn]

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);

}
```