void handler( alias dg )()
{
  alias ParameterTypeTuple!( typeof(dg) ) TParamTuple;
  alias ReturnType!(dg) TResult;

  TParamTuple params;
  foreach( ref param; params )
  {}
}

double hello( double i )
{
  writefln( "zomfg ", i );
}

int main( in string[] )
{
  handler!(hello)();
}

This code yields error on "foreach( ref param; params )": Error : No storage class for value param

Best regards,
Daniel

On Sun, Nov 2, 2008 at 7:56 PM, Daniel Ribeiro Maciel <daniel.maciel@gmail.com> wrote:
> void handler( alias dg )()
> {
>  alias ParameterTypeTuple!( typeof(dg) ) TParamTuple;
>  alias ReturnType!(dg) TResult;
>
>  TParamTuple params;
>  foreach( ref param; params )
>  {}
> }
>
> double hello( double i )
> {
>  writefln( "zomfg ", i );
> }
>
> int main( in string[] )
> {
>  handler!(hello)();
> }
>
> This code yields error on "foreach( ref param; params )": Error : No storage class for value param
>
> Best regards,
> Daniel
>
>

For some reason you can't use 'ref' on tuple foreaches.  You'll just have to use the index-value version:

foreach(i, param; params) { /* set params[i] here */ }