Re: symmetric signed types

[Timon Gehr]

On 01/25/2014 01:57 PM, Dominikus Dittes Scherkl wrote:

...
Walter wrote:
"There's no NaN for integrals."

At least the carry-bit is already available in hardware. So the save
type doesn't incure much performance loss in operations. On the other
hand comparison, assignment and casts become slower by a factor 2 or 3.
And then comparison cannot be implemented fully correct with the current
operator overloding system of D.

Why not?

struct S{
    auto opCmp(S r){ return float.nan; }
}

void main(){
    S s;
    assert(s!<>=s);
}