• Vitaliy Fadeev (22/22) Sep 18 2023 Detect 8-bit alligned type TXY by TX,TY.
• Richard (Rikki) Andrew Cattermole (7/7) Sep 18 2023 I assume what you are wanting is to get the alignment for a given type?
• Vitaliy Fadeev (28/37) Sep 18 2023 Thank, Richard.
• Imperatorn (3/32) Sep 21 2023 Do a mixin

Vitaliy Fadeev <vital.fadeev gmail.com> writes:

Detect 8-bit alligned type TXY by TX,TY.

```d
     union
     {
         struct
         {
             TX x;
             TY y;
         }
         TXY xy;
     }

     alias TXY = Detect!(TX,TY);
```

Wanted:

```d
Detect( uint, uint )     == ulong;
Detect( uint, ubyte )    == ulong;
Detect( ushort, ushort ) == uint;
Detect( ushort, ubyte )  == uint;
```

Is there a D-trait or D-function for detect TXY (named for 
example ```Detect``` in code above) ?

"Richard (Rikki) Andrew Cattermole" <richard cattermole.co.nz> writes:

I assume what you are wanting is to get the alignment for a given type?

https://dlang.org/spec/property.html#alignof

If instead you want the offset of a given field that's different.

``T.field.offsetof``

https://dlang.org/spec/struct.html#struct_field_properties

Note: alignment cannot be represented by a type, it can only be 
represented by a number (for instance it could be 3).

Vitaliy Fadeev <vital.fadeev gmail.com> writes:

On Tuesday, 19 September 2023 at 06:33:25 UTC, Richard (Rikki) 
Andrew Cattermole wrote:
 I assume what you are wanting is to get the alignment for a 
 given type?

 https://dlang.org/spec/property.html#alignof

 If instead you want the offset of a given field that's 
 different.

 ``T.field.offsetof``

 https://dlang.org/spec/struct.html#struct_field_properties

 Note: alignment cannot be represented by a type, it can only be 
 represented by a number (for instance it could be 3).

Thank, Richard.

```.offsetof...``` mmm...

May be exists some like:

```d
// TXYXY = Detect!(TX,TX)
// Detect!(uint,uint) == ulong
template Detect(TX,TY)
{
     static if ( TX.sizeof + TY.sizeof <= 8 )
         alias Detect = ubyte;
     else
     static if ( TX.sizeof + TY.sizeof <= 16 )
         alias Detect = ushort;
     else
     static if ( TX.sizeof + TY.sizeof <= 32 )
         alias Detect= uint;
     else
     static if ( TX.sizeof + TY.sizeof <= 64 )
         alias Detect= ulong;
     else
     static if ( TX.sizeof + TY.sizeof <= 128 )
         alias Detect= ucent;
     else
         static assert( 0, "Expected size TX+TY <= 128" );
}
```

Imperatorn <johan_forsberg_86 hotmail.com> writes:

On Tuesday, 19 September 2023 at 06:41:49 UTC, Vitaliy Fadeev 
wrote:
 On Tuesday, 19 September 2023 at 06:33:25 UTC, Richard (Rikki) 
 Andrew Cattermole wrote:
 [...]

 Thank, Richard.

 ```.offsetof...``` mmm...

 May be exists some like:

 ```d
 // TXYXY = Detect!(TX,TX)
 // Detect!(uint,uint) == ulong
 template Detect(TX,TY)
 {
     static if ( TX.sizeof + TY.sizeof <= 8 )
         alias Detect = ubyte;
     else
     static if ( TX.sizeof + TY.sizeof <= 16 )
         alias Detect = ushort;
     else
     static if ( TX.sizeof + TY.sizeof <= 32 )
         alias Detect= uint;
     else
     static if ( TX.sizeof + TY.sizeof <= 64 )
         alias Detect= ulong;
     else
     static if ( TX.sizeof + TY.sizeof <= 128 )
         alias Detect= ucent;
     else
         static assert( 0, "Expected size TX+TY <= 128" );
 }
 ```

Do a mixin