Benjamin Thaut, yes I know. but here is an example, if I add a class to the code like that:

module main;

extern (C) void* _Dmodule_ref = null;

extern (C) void printf(const char*, ...);

extern (C) void puts(const char*);
extern (C) void exit(int);

class A {
        int a = 100;
        int b = 200;

};

extern (C) void main() {
        scope(exit) {
                puts("Exiting!");
                exit(0);
        }

        A a; printf("%d %d\n", a.a, a.b);
}