I think the code below is supposed to compile...

struct S
{
   union Anon
   {
      int Int;
      real Atom;
   }
}

void main()
{
    S test;
    test.Anon.Int = 2;  // line #13
}

But I get this message ...

  test.d(13): need 'this' to access member Int


I need to change it to this to get it to compile ...

struct S
{
   union Anon
   {
      int Int;
      real Atom;
   }
   Anon A;
}

void main()
{
    S test;
    test.A.Int = 2;
}

-- 
Derek
Melbourne, Australia
1/06/2005 1:02:30 PM

Derek Parnell wrote:
> I think the code below is supposed to compile...
> 
> struct S
> {
>    union Anon
>    {
>       int Int;
>       real Atom;
>    }
> }
> 

I think anonymous unions have no names (hence anonymous)
So strictly speaking, the union above is probably not anonymous.

This should probably compile:
 struct S
 {
    union
    {
       int Int;
       real Atom;
    }
 }

> void main()
> {
>     S test;
>     test.Anon.Int = 2;  // line #13
> }
> 
> But I get this message ...
> 
>   test.d(13): need 'this' to access member Int

Anon is the type name, not an instance. I think that's why it needs a "this" (i.e. an instance)

> 
> 
> I need to change it to this to get it to compile ...
> 
> struct S
> {
>    union Anon
>    {
>       int Int;
>       real Atom;
>    }
>    Anon A;
> }
> 
> void main()
> {
>     S test;
>     test.A.Int = 2;
> }
> 

This (I think) is c++'s way of doing it .. it's definitly not anonymous.

On Tue, 31 May 2005 21:12:14 -0600, Hasan Aljudy wrote:

> Derek Parnell wrote:
>> I think the code below is supposed to compile...
>> 
>> struct S
>> {
>>    union Anon
>>    {
>>       int Int;
>>       real Atom;
>>    }
>> }
>> 
> 
> I think anonymous unions have no names (hence anonymous)
> So strictly speaking, the union above is probably not anonymous.
> 
> This should probably compile:
>   struct S
>   {
>      union
>      {
>         int Int;
>         real Atom;
>      }
>   }

Thanks. Yes it does.

But I guess it means only one anonymous union per struct though ;-)

-- 
Derek
Melbourne, Australia
1/06/2005 1:26:13 PM

Derek Parnell wrote:
> But I guess it means only one anonymous union per struct though ;-)

Actually no, no it doesn't..  I just tested with this:

# import std.stdio;
#
# struct S {
#   int Si;
#
#   union {
#     int   Ai;
#     float Af;
#   }
#
#   union {
#     int   Bi;
#     float Bf;
#   }
# }
#
# void main() {
#   S s;
#
#   s.Ai = 123;
#   s.Bf = 3.14;
#
#   writefln("s.Ai : ", s.Ai);
#   writefln("s.Bf : ", s.Bf);
#
#   s.Af = 4.2;
#
#   writefln("s.Af : ", s.Af);
#   writefln("s.Bf : ", s.Bf);
# }

Although granted, naming might be interesting when having multiple anonymous unions.

-- Chris Sauls

Derek, anonymous means 'no type name'
and not 'no variable name'

variable name - alias of some memory location
must always exist if you want to store something there.
So you should write something like this:

 struct S
  {
     union
     {
        int Int;
        real Atom;
     } var;
  }

And then

S s;
s.var.Int = 28;


Andrew.


"Derek Parnell" <derek@psych.ward> wrote in message news:14ds0mvtn12la$.1nc9wu744dnbg.dlg@40tude.net...
>I think the code below is supposed to compile...
>
> struct S
> {
>   union Anon
>   {
>      int Int;
>      real Atom;
>   }
> }
>
> void main()
> {
>    S test;
>    test.Anon.Int = 2;  // line #13
> }
>
> But I get this message ...
>
>  test.d(13): need 'this' to access member Int
>
>
> I need to change it to this to get it to compile ...
>
> struct S
> {
>   union Anon
>   {
>      int Int;
>      real Atom;
>   }
>   Anon A;
> }
>
> void main()
> {
>    S test;
>    test.A.Int = 2;
> }
>
> -- 
> Derek
> Melbourne, Australia
> 1/06/2005 1:02:30 PM

Chris Sauls wrote:
<snip>
> Although granted, naming might be interesting when having multiple anonymous unions.

An anonymous union doesn't create a scope.  And so it's illegal for names to collide between them.

Stewart.

-- 
My e-mail is valid but not my primary mailbox.  Please keep replies on the 'group where everyone may benefit.

Andrew Fedoniouk wrote:
> Derek, anonymous means 'no type name'
> and not 'no variable name'
> 
> variable name - alias of some memory location
> must always exist if you want to store something there.
> So you should write something like this:
> 
>  struct S
>   {
>      union
>      {
>         int Int;
>         real Atom;
>      } var;
>   }
<snip top of upside-down reply>

Illegal in D.  Should be

    struct S
    {
        union Var
        {
            int Int;
            real Atom;
        }
        Var var;
    }

Stewart.

-- 
My e-mail is valid but not my primary mailbox.  Please keep replies on the 'group where everyone may benefit.

"Stewart Gordon" <smjg_1998@yahoo.com> wrote in message news:d7klmr$2090$1@digitaldaemon.com...
> Andrew Fedoniouk wrote:
>> Derek, anonymous means 'no type name'
>> and not 'no variable name'
>>
>> variable name - alias of some memory location
>> must always exist if you want to store something there.
>> So you should write something like this:
>>
>>  struct S
>>   {
>>      union
>>      {
>>         int Int;
>>         real Atom;
>>      } var;
>>   }
> <snip top of upside-down reply>
>
> Illegal in D.  Should be
>
>     struct S
>     {
>         union Var
>         {
>             int Int;
>             real Atom;
>         }
>         Var var;
>     }
>
> Stewart.

Thanks Stewart. It was my Cism.