[Issue 13489] Boolean semantics of floating point types should use "<> 0"

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13489

Ketmar Dark <ketmar at ketmar.no-ip.org> changed:

           What    |Removed                     |Added
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                 CC|                            |ketmar at ketmar.no-ip.org

--- Comment #3 from Ketmar Dark <ketmar at ketmar.no-ip.org> ---
(In reply to Walter Bright from comment #2)
> Having cast(bool)d yield different results than d!=0 to me is very
> surprising behavior.
for me too. NaN is clearly not 0, so it's 'true'.

but maybe compiler should produce warning telling programmer that he is about
to summon a dragon? i.e. for implicit converts to boolean, like `if (d)` and
`assert(d)` compiler will tell that "implicit convertsion of double to boolean
leads to undesired results, please use explicit cast(bool)".

as for '!=' vs '<>'... i don't know. it's easy to emit a warning, but i can't
think out sane method to hush the compiler if "!=" is what i really want.

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