cleaner approach of variadic arg deduce, inspired by Jarrett Billingsley

[Davidl]

the following is trying to deduce the variadic call to a chain of function  
call.
the problem is only appeard on current DMD when deduce the last parameter  
type double
it matches both
this(float y,A a...)
and
this(float y)

but actually it should just match this(float y) , and this would result  
the correct
chain of calling.

import std.stdio;
import std.string;
class A
{
     static char[][] output;
     this(int x,A a...){
	    output~= format(`int`,x);
     }
  /*   this(float x, A a...)
     {
     }*/
     this(int x)
     {
	    output~= format(`int`,x);
     }
     this(float x)
     {
	    output~= format(`float`,x);
     }
}

void func(A a...)
{
     foreach_reverse(k;a.output)
     {
   	writef(k);
     }
     a.output.length = 0;
}

void main()
{
	func(1,4,2.0);
	func(1,5,2.0);
}