deprecate boolean evaluation of floating point and character types

[Quirin Schroll]

On Thursday, 16 May 2024 at 20:36:17 UTC, Nick Treleaven wrote:
> On Thursday, 16 May 2024 at 18:03:30 UTC, Quirin Schroll wrote:
>> On Wednesday, 1 May 2024 at 10:01:29 UTC, Nick Treleaven wrote:
>>> But the meaning of boolean evaluation of a number is to check 
>>> if it is non-zero. That is well established from C.
>>
>> Without looking it up, if `x` is `-0.0`, does `!x` evaluate to 
>> `true` or `false`?
>>
>> Hint: Negative zero compares equal to zero (`x == 0.0`), but 
>> it’s not zero: `x !is 0.0`.
>>
>> Possibly after looking it up, does the answer make sense to 
>> you?
>>
>> Even if you’re 100% sure, would you bet most D programmers get 
>> it right?
>
> `-0.0` would convert to integer 0, which in turn is false. When 
> I said non-zero, that is well defined for integers. So I'm not 
> sure why you think it's surprising that `!-0.0` is true.

Because it has a non-zero bit pattern. It does something rather 
nontrivial.