The Comma Operator's Deprecation Can't Come Soon Enough

[Meta via Digitalmars-d]

Spot the bug:

template flattenedType(R, uint depth = uint.max)
if (isInputRange!R)
{
        static if (depth > 0)
        {
                static if (!isInputRange!(typeof(R.init.front)))
                {
                        alias flattenedType = typeof(R.init.front, depth - 1);
                }
                else
                {
			alias flattenedType = flattenedType!(typeof(R.init.front), 
depth - 1);
                }
        }
        else
        {
                alias flattenedType = typeof(R.init.front);
        }
}
I'll give you a hint: the bug causes flattenedType!R to always 
returned uint.