Static foreach.

[Jarrett Billingsley]

I am overjoyed by the variadic templates.  This is how variadic functions 
_should_ be, and this opens up so many other possibilities as well.

One of the cooler things is the ability to iterate over a tuple with 
foreach.  So:

void print(T...)(T args)
{
    foreach(arg; args)
        writef(arg);

    writefln();
}

This is great.  DMD even unrolls this loop, making it a sort of "static 
foreach."

But what _else_ could this tuple/foreach facility be used for?

Let's assume the new "foreaching over a tuple" had to be done with "static 
foreach", so the above code would simply have a "static" before the 
"foreach".  Not a large sacrifice to make, and it also makes it explicit 
that the loop is looped at compile time and not at runtime.

Now, since static foreach is no longer a "statement", it can appear where 
statements can't, like inside regular templates.  Then you can iterate over