Re: How to expand an expression along with a parameter tuple?

[TommiT]

On Monday, 17 June 2013 at 12:21:31 UTC, Artur Skawina wrote:

A more correct, but a bit less readable version (the types of 
'values' and 'arr'
elements do not have to match) would be:

   void bar(T...)(T values) {
      static if (T.length) {
         NTup!(T.length, typeof(arr[T[0].init])) tmp;
         foreach (i, ref v; values)
            tmp[i] = arr[v]*10;
         foo(tmp);
      }
      else
         foo();
   }

   template NTup(size_t N, T...) {
      static if (N>1)
         alias NTup = NTup!(N-1, T, T[$-1]);
      else
         alias NTup = T;
   }

artur

Argh, that's a lot of boilerplate. Thanks for pointing this out. 
I didn't notice in your previous example that the expression 
types had to match with the parameter types. Now I really do 
think that we need the C++ ellipsis notation (it's just the 
ellipsis can be omitted when it would be right next to the tuple):

void bar(T...)(T values)
{
    foo((arr[values] * 10)...);
}