Forbid dynamic arrays in boolean evaluation contexts

[Daniel Murphy]

"bearophile" <bearophileHUGS at lycos.com> wrote in message 
news:fqjmqdhpenxnfadxwgbx at forum.dlang.org...
> Daniel Murphy:
>
>> I am in favour of deprecating/removing this, then bringing it back so 
>> that
>> if (arr)
>> is the same as
>> if (arr.length)
>
> That was my original idea :-) And it seems a nice idea.
>
> But turning something into a deprecation and later error is useful because 
> it doesn't introduce bugs. While if you later assign it some other 
> semantics, old D code will behave differently (despite it's probably 
> potentially buggy code in the first place).
>
> So it's a matter of how much you want to break old D code.
>
> Bye,
> bearophile

The deprecation process is long and slow, so when it finally finishes the 
error stage we can evaluate how much legacy code we risk breaking.  Even if 
we never bring in the new meaning removing it will improve the language.