Unable to call each on a lockstep range containing 2 or more ranges

[John Colvin via Digitalmars-d-learn]

On Wednesday, 18 November 2015 at 12:20:42 UTC, maik klein wrote:
> https://stackoverflow.com/questions/33779822/unable-to-call-each-on-a-lockstep-range-containing-2-or-more-ranges
>
> http://dpaste.dzfl.pl/76c79f1f12ab
>
> void main(){
>   import std.container;
>   import std.stdio;
>   import std.algorithm.iteration;
>   import std.range;
>   Array!int ai = [1,2,3,4];
>   Array!int ai1 = [1,2,3,4];
>   Array!int ai2 = [1,2,3,4];
>
>   auto arange = lockstep(ai[],ai1[]);
>   arange.each!((a,b) => writeln(a, b));
>
>   auto arange2 = lockstep(ai[],ai1[],ai2[]);
>   arange2.each!((a,b,c) => writeln(a, b, c));
> }
>
> Error: template std.algorithm.iteration.each cannot deduce 
> function from argument types !((a, b, c) => writeln(a, b, 
> c))(Lockstep!(RangeT!(Array!int), RangeT!(Array!int), 
> RangeT!(Array!int))), candidates are: 
> /opt/compilers/dmd2/include/std/algorithm/iteration.d(820):
> std.algorithm.iteration.each(alias pred = "a")
>
>
> "arange" works but "arange2" doesn't because the compiler is 
> unable to deduce the the function. The error even appears if I 
> explicitly add the argument types.

I think this is a bug, please report it at issues.dlang.org and 
perhaps there will be an explanation or it will be fixed.
In the mean time, something like this should work:

   auto arange2 = zip(ai[],ai1[],ai2[]);

   arange2.each!((t) => writeln(t[0], t[1], t[2]));
   // or if you really must have the names:
   arange2.each!((t) => (a,b,c){ writeln(a, b, c); }(t.expand));