Tuples not working?

Ali Çehreli via Digitalmars-d-learn digitalmars-d-learn at puremagic.com
Fri Jan 9 10:50:19 PST 2015


On 01/09/2015 10:42 AM, Jonathan Marler wrote:
> import std.stdio;
> import std.typecons;
> void main()
> {
>    alias TL = Tuple!(int, long, float);
>    foreach (i, T; TL)
>      writefln("TL[%d] = %s", i, typeid(T));
> }
>
> Why is this not working?
>
> D:\dmd2\windows\bin\..\..\src\phobos\std\typecons.d(419): Error: need
> 'this' for '_expand_field_0' of type 'int'
> D:\dmd2\windows\bin\..\..\src\phobos\std\typecons.d(419): Error: need
> 'this' for '_expand_field_1' of type 'long'
> D:\dmd2\windows\bin\..\..\src\phobos\std\typecons.d(419): Error: need
> 'this' for '_expand_field_2' of type 'float'
>
> Tried to compile using dmd 2.066 and dmd 2.067.  Code taken directly
> from dlang website here (http://dlang.org/tuple.html). Thanks.

Broken documentation presumable because the feature changed later on. 
The code works if you we std.typetuple.TypeTuple:

import std.stdio;
import std.typetuple;

void main()
{
   alias TL = TypeTuple!(int, long, float);
   foreach (i, T; TL)
       writefln("TL[%d] = %s", i, typeid(T));
}

Ali



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