BigInt bool assign

[Timon Gehr]

On 12/24/2011 11:33 AM, Don wrote:
> On 24.12.2011 02:30, Derek wrote:
>> On Sat, 24 Dec 2011 09:19:26 +1100, bearophile
>> <bearophileHUGS at lycos.com> wrote:
>>
>>> This is why it's better to avoid casts, not requiring them in the
>>> first place, unless they are useful. In this case I think a cast
>>> introduces more danger than the risks caused by implicit bool->int
>>> conversions.
>>
>> If we assume that explicit casts are required for bool->int conversion,
>> can you show some code in which this could cause a problem?
>
> I think stuff like
> int z += x > y;
> should ideally require a cast.

What does anyone gain by adding bulky 'cast(int)' noise to their code 
that is nothing but a no-op?

> That's a crazy operation.

s/craz/nift/

>
> The problem is compatibility with ancient C code (pre-C99), where you
> may find:
>
> alias int BOOL;
>
> BOOL b = x > y;
>
> Although BOOL is typed as 'int', it really has the semantics of 'bool'.
> We have an example of this in D1's opEquals().
> I think this is reason why implicit conversion bool -> int exists.

It exists because it is handy and makes sense. Would you also want to 
ban implicit short -> int conversion?

>
> BTW, great to see you again, Derek!