DMD 0.148 release

[Ivan Senji]

Regan Heath wrote:
> On Mon, 27 Feb 2006 08:48:11 +1100, Derek Parnell <derek at psych.ward> wrote:
> 
>> On Mon, 27 Feb 2006 07:56:10 +1100, Regan Heath <regan at netwin.co.nz>  
>> wrote:
>>
>>> On Sun, 26 Feb 2006 18:46:10 +0000 (UTC), Thomas Kuehne  
>>> <thomas-dloop at kuehne.cn> wrote:
>>>
>>>> Charles schrieb am 2006-02-26:
>>>>
>>>>>
>>>>> > Can't we simply treat zero as false and non-zero as true as we C
>>>>> > programmers always do?
>>>>>
>>>>> I agree, I still don't get what the 'true bool' fuss is about .
>>>>
>>>>
>>>> if(b==1) { ... }
>>>>
>>>> instead of
>>>>
>>>> if(b!=0) { ... }
>>>>
>>>> can be found in quite a lot of C code ...
>>>
>>>
>>> So?
>>>
>>> Assuming:
>>>
>>>   - 'b' is a bool
>>>   - a bool can only have 2 values, 'true' and 'false'
>>>   - when you convert/promote a bool to an int you get: 'true'->'1',  
>>> 'false'->'0'
>>>   - when you convert/promote an int to bool you get: '0'->false,  
>>> '!0'->'true'
>>>
>>> Then:
>>>
>>> if(b==1) { ... }
>>>
>>> results in 'b' being converted to int, giving it the value 1, and 
>>> the  comparrison working correctly.
>>>
>>> Right?
>>
>>
>> If it implemented that way, yes. However the problem with
>>
>>    if(b == 1)
>>
>> is that the reader (future maintainer) might be mislead into thinking  
>> that 'b' is an integer and may try to use it as such by mistake. It 
>> is  better to inform the reader about the true nature of 'b' by writing
>>
>>    if (b == true)
>>
>> in or to remove such ambiguity.
> 
> 
> Sure, but the example was old C code, presumably copied into a D source  
> file and used. Or perhaps a C programmer not used to having bool using 
> '1'  for true. I was just pointing out that it was likely to work, not 
> that it  was as clear as it could be.

I usually want my code not only to likely work. That is just not enough.
What if someone writes D compiler for a strange CPU on which parity 
instructions are faster than comparing to 0 or 1, then we could have 
"true" == more zeros, "false" == more ones.

Or there could be any other imaginable implementation of bools and each 
and every one will break on code like if(b==1), if(b==0), while(b), if(3)...