I must to put a 'struct definition' inside a 'static if block' but other 'struct definition' doesn't see them.

static if(_WIN32IE !< 0x0400)
struct TVINSERTSTRUCT{

  HTREEITEM hparent     ;
  HTREEITEM hinsertafter;

  union tagDUMMYUNIONNAME{
    TVITEMEX itemex;
    TVITEM item;
  }

  tagDUMMYUNIONNAME DUMMYUNIONNAME;

  alias DUMMYUNIONNAME.itemex itemex;
  alias DUMMYUNIONNAME.item   item  ;

}
else
struct TVINSERTSTRUCT{
  HTREEITEM hParent;
  HTREEITEM hInsertAfter;
  TVITEM item;
}

static if(_WIN32IE !< 0x0600)
struct TVITEMEX{
  UINT      mask         ;
  HTREEITEM item         ;
  UINT      state        ;
  UINT      statemask    ;
  TSTR      text         ;
  UINT      textmax      ;
  INT       image        ;
  INT       selectedimage;
  INT       children     ;
  LPARAM    lparam       ;
  INT       integral     ;
  UINT      stateex      ;
  HWND      hwnd         ;
  INT       expandedimage;
}
else
struct TVITEMEX{
  UINT      mask         ;
  HTREEITEM item         ;
  UINT      state        ;
  UINT      statemask    ;
  TSTR      text         ;
  UINT      textmax      ;
  INT       image        ;
  INT       selectedimage;
  INT       children     ;
  LPARAM    lparam       ;
  INT       integral     ;
}

It works only if I declare TVITEMEX before TVINSERTSTRUCT. And the second question, Is it possible to use anonymous unions and structs?

Zarathustra wrote:
> I must to put a 'struct definition' inside a 'static if block' but other 'struct definition' doesn't see them.
> 
> static if(_WIN32IE !< 0x0400)
> struct TVINSERTSTRUCT{
> 
>   HTREEITEM hparent     ;
>   HTREEITEM hinsertafter;
> 
>   union tagDUMMYUNIONNAME{
>     TVITEMEX itemex;
>     TVITEM item;
>   }
> 
>   tagDUMMYUNIONNAME DUMMYUNIONNAME;
>     alias DUMMYUNIONNAME.itemex itemex;
>   alias DUMMYUNIONNAME.item   item  ;
> 
> }
> else
> struct TVINSERTSTRUCT{
>   HTREEITEM hParent;
>   HTREEITEM hInsertAfter;
>   TVITEM item;
> }
> 
> static if(_WIN32IE !< 0x0600)
> struct TVITEMEX{
>   UINT      mask         ;
>   HTREEITEM item         ;
>   UINT      state        ;
>   UINT      statemask    ;
>   TSTR      text         ;
>   UINT      textmax      ;
>   INT       image        ;
>   INT       selectedimage;
>   INT       children     ;
>   LPARAM    lparam       ;
>   INT       integral     ;
>   UINT      stateex      ;
>   HWND      hwnd         ;
>   INT       expandedimage;
> }
> else
> struct TVITEMEX{
>   UINT      mask         ;
>   HTREEITEM item         ;
>   UINT      state        ;
>   UINT      statemask    ;
>   TSTR      text         ;
>   UINT      textmax      ;
>   INT       image        ;
>   INT       selectedimage;
>   INT       children     ;
>   LPARAM    lparam       ;
>   INT       integral     ;
> }
> 
> It works only if I declare TVITEMEX before TVINSERTSTRUCT. And the second question, Is it possible to use anonymous unions and structs?

Does that compile???   It shouldn't. !< is a floating-point operator.

Don Wrote:

> Does that compile???   It shouldn't. !< is a floating-point operator.


Of course that compile (thanks Got DMD behaviors logically). In this case !< mean nothing less >= NOT GREATER THAN is semantically same as GREATER OR EQUAL.

Yes, you're right !< is a floationg-point operator but it doesn't matter.

The problem is:
struct B{
  A a;
}

struct A{
}

works ok, but
struct B{
  A a;
}

static if(TRUE) struct A{
}

causes:
  Error: identifier 'A' is not defined
  Error: A is used as a type
  Error: variable B.a voids have no value

Matthew:

A cleaned up case:

struct B { A a; }

static if(true)
  struct A {}

void main() {}

I think this may be a forward reference bug.

Bye,
bearophile

On Mon, 14 Dec 2009 15:43:49 +0100, Zarathustra <adam.chrapkowski@gmail.com> wrote:

> I must to put a 'struct definition' inside a 'static if block' but other 'struct definition' doesn't see them.
>
> static if(_WIN32IE !< 0x0400)
> struct TVINSERTSTRUCT{
>
>   HTREEITEM hparent     ;
>   HTREEITEM hinsertafter;
>
>   union tagDUMMYUNIONNAME{
>     TVITEMEX itemex;
>     TVITEM item;
>   }
>
>   tagDUMMYUNIONNAME DUMMYUNIONNAME;
>  alias DUMMYUNIONNAME.itemex itemex;
>   alias DUMMYUNIONNAME.item   item  ;
>
> }
> else
> struct TVINSERTSTRUCT{
>   HTREEITEM hParent;
>   HTREEITEM hInsertAfter;
>   TVITEM item;
> }
>
> static if(_WIN32IE !< 0x0600)
> struct TVITEMEX{
>   UINT      mask         ;
>   HTREEITEM item         ;
>   UINT      state        ;
>   UINT      statemask    ;
>   TSTR      text         ;
>   UINT      textmax      ;
>   INT       image        ;
>   INT       selectedimage;
>   INT       children     ;
>   LPARAM    lparam       ;
>   INT       integral     ;
>   UINT      stateex      ;
>   HWND      hwnd         ;
>   INT       expandedimage;
> }
> else
> struct TVITEMEX{
>   UINT      mask         ;
>   HTREEITEM item         ;
>   UINT      state        ;
>   UINT      statemask    ;
>   TSTR      text         ;
>   UINT      textmax      ;
>   INT       image        ;
>   INT       selectedimage;
>   INT       children     ;
>   LPARAM    lparam       ;
>   INT       integral     ;
> }
>
> It works only if I declare TVITEMEX before TVINSERTSTRUCT.

Looks to me like a forward reference problem. Sadly, there
still are some of those in the language.


> And the second question, Is it possible to use anonymous unions
> and structs?

Yes. http://www.digitalmars.com/d/2.0/faq.html#anonymous


struct Foo
{
    union { int a; int b; }  // I HAZ NO NAYM
    struct { int c; int d; } // I HAZ NO NAYM
}

-- 
Simen

Simen kjaeraas Wrote:

> Looks to me like a forward reference problem. Sadly, there still are some of those in the language.
> 
> Yes. http://www.digitalmars.com/d/2.0/faq.html#anonymous
> 
> 
> struct Foo
> {
>      union { int a; int b; }  // I HAZ NO NAYM
>      struct { int c; int d; } // I HAZ NO NAYM
> }
> 
> -- 
> Simen

Thanks Simen. I hoped D will be bugless and static if will be possible inside enums.

Best regards

Zarathustra <adam.chrapkowski@gmail.com> wrote:

> Thanks Simen. I hoped D will be bugless and static if will be possible inside enums.

Static if will probably never be usable inside enums. The best way to
get something like it - at least currently - is to use string mixins
and/or the defineEnum template in std.typecons.

-- 
Simen