• MattCoder (37/37) Jun 14 2013 Hi,
• bearophile (8/13) Jun 14 2013 You have to verify in the function constraint that the lengths
• MattCoder (9/11) Jun 14 2013 In fact that was intentional, because sometimes I just want few

"MattCoder" <mattcoder hotmail.com> writes:

Hi,

Sooner I asked about this ([Doubt] Variadic arguments as 
reference (Possible?) - - 
http://forum.dlang.org/thread/jwujjhjizkovvmbegaio forum.dlang.org).

In fact my intend was to recreate a feature that I like in 
Python, where you can assign variables from a tuple, e.g.:

pos = (10, 20)
x,y = Pos

or

RGB = (255,255,255)
r,g,b = RGB

Thanks to the fellows who help me early morning, I wrote the 
workable version below:

import std.stdio;
import std.typecons;
import std.variant;

void tupleToVar(A, T...)(A inTuple, ref T listParams){
   foreach(i, ref p; listParams){
     if(!(i<inTuple.length))
       break;

     p = inTuple[i];
   }
}

void main()
{
     auto myTuple = tuple(1,2,3,"Test");
     Variant a, b, c, d;
     tupleToVar(myTuple, a, b, c, d);
     writeln(a);
     writeln(b);
     writeln(c);
     writeln(d);
}

dpaste: http://dpaste.dzfl.pl/6f3f25d0

It would be nice if it could appear more like python, but I think 
this would be a internal dev.

Matheus.

"bearophile" <bearophileHUGS lycos.com> writes:

MattCoder:

 void tupleToVar(A, T...)(A inTuple, ref T listParams){

I think in the C++11 STL a similar function is named tie.


     if(!(i<inTuple.length))
       break;

You have to verify in the function constraint that the lengths 
match.


 It would be nice if it could appear more like python, but I 
 think this would be a internal dev.

There is a DIP about it, but it's currently stalled:
http://wiki.dlang.org/DIP32

Bye,
bearophile

"MattCoder" <mattcoder hotmail.com> writes:

On Saturday, 15 June 2013 at 00:47:01 UTC, bearophile wrote:
 You have to verify in the function constraint that the lengths 
 match.

In fact that was intentional, because sometimes I just want few 
items from a tuple not all.

For example:

auto RGB = tuple(255, 125, 50);
Variant r,g;
tupleToVar(RGB, r, g); // I just want the red and green values 
from a tuple

Matheus.