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Detect 8-bit alligned type TXY by TX,TY.
September 19
Gravatar of Vitaliy FadeevPosted by Vitaliy FadeevReply
Vitaliy Fadeev
Gravatar of Vitaliy Fadeev


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

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

    alias TXY = Detect!(TX,TY);

Wanted:

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) ?

September 19
Gravatar of Richard (Rikki) Andrew CattermolePosted by Richard (Rikki) Andrew Cattermole
in reply to Vitaliy Fadeev		Reply
Richard (Rikki) Andrew Cattermole
Gravatar of Richard (Rikki) Andrew Cattermole
Posted in reply to Vitaliy Fadeev


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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).
September 19
Gravatar of Vitaliy FadeevPosted by Vitaliy Fadeev
in reply to Richard (Rikki) Andrew Cattermole		Reply
Vitaliy Fadeev
Gravatar of Vitaliy Fadeev
Posted in reply to Richard (Rikki) Andrew Cattermole


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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:

// 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" );
}
September 21
Gravatar of ImperatornPosted by Imperatorn
in reply to Vitaliy Fadeev		Reply
Imperatorn
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Posted in reply to Vitaliy Fadeev


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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:

// 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