Is this supposed to be a bug?

[Daniel Ribeiro Maciel]

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