make (a < b < c) illegal?

[Reiner Pope]

Michiel wrote:
>> I give up. I can't work out how to create this functionality
>> for an arbitary number of arguments.
> 
> You need to use recursion, not loops. I'm not sure how the syntax works exactly,
> but it might look something like this:
> 
> bool ordered(T1, T2, Trest ...)(T1 first, T2 second, Trest rest) {
>     return (first < second) && ordered(second, rest);
> }
You can use a foreach-over-tuple instead of recursion:

bool ordered(T...)(T data)
{
     foreach(i, d; data)
     {
        static if (i < data.length - 1)
            if (! (d < data[i+1])) return false;
     }
     return true;
}