Eliminate the baroque floating-point operators a la !<>=

[Jason House]

Andrei Alexandrescu Wrote:

> Hello,
> 
> 
> I think the floating-point operators:
> 
>    a !<>= b
>    a !<> b
>    a <> b
>    a <>= b
>    a !> b
>    a !>= b
>    a !< b
>    a !<= b
> 
> are useless. A simple peephole optimization in the compiler can 
> automatically rewrite NaN test followed by regular operations into the 
> operations above, for example:
> 
> isNaN(a) || isNan(b) || a >= b
> 
> is the same as
> 
> a !< b
> 
> This is in keeping with what the compiler does when seeing code like:
> 
> a = x / y;
> b = x % y;
> 
> There's a peephole optimization that groups the / and the % together 
> into an assembler operation that does both. If this is the way to go, we 
> better be congruent and use explicit isNaN tests (that are then 
> optimized) instead of defining eight extra operators.
> 
> 
> Andrei

I like the concept of NaN-aware operators, but IMHO, the most common operators are prone to misuse. If D moves for the peephole optimizations, I'd request a function called ordered(a,b) in addition to isNaN(a). Non-nullable and non-nanable types would be handy...