C.h to D conversion (structs)

[Chris via Digitalmars-d-learn]

I've converted a C.h file to D according to this guide:
http://wiki.dlang.org/Converting_C_.h_Files_to_D_Modules

and examples in deimos:

https://github.com/D-Programming-Deimos/

However, I get an error when trying to use a struct that uses 
structs.

struct A
{
  size_t i;
}

struct B
{
  size_t x;
}

struct C
{
  A a;
  B b;
}

The error I get is something like

undefined reference to `_D3test7testmodule13A6__initZ'
undefined reference to `_D3test7testmodule13B6__initZ'

// The C header would look like this:

typedef struct _A
{
  size_t i;
} A;

typedef struct _B
{
  size_t x;
} B;

typedef struct _C
{
  A a;
  B b;
} C;

Also, what do I do with C structs that contain the following:

typedef struct _A
{
  struct _A *next;
  struct _A *prev;
} A;

Thanks.