assert(0) behavior

[John Colvin via Digitalmars-d]

On Tuesday, 4 August 2015 at 22:06:06 UTC, Ola Fosheim Grøstad 
wrote:
> On Tuesday, 4 August 2015 at 20:21:24 UTC, Walter Bright wrote:
>> On 8/3/2015 8:37 PM, Ola Fosheim =?UTF-8?B?R3LDuHN0YWQi?= 
>> <ola.fosheim.grostad+dlang at gmail.com> wrote:
>>> The input/environment/code distinction does not work very 
>>> well.
>>
>> Sure it does. If your user ever sees an assert failure 
>> message, your program has a bug in it.
>
> Yes.
>
>> Keep that in mind when designing the code, and the distinction 
>> will become clear.
>
> The input/code distinction is too simplistic.
>
> Example 1: It makes perfect sense to assert (or assume) that a 
> value from a hardware register or cpu instruction is within 
> range. If the assert fires, it is the spec/code that is wrong, 
> not the input. So you are testing the specification in the code 
> against well defined input.
>
> Example 2: It makes perfect sense to enforce that a return 
> value from a plugin library is within range to maintain main 
> program integrity and shut out a misbehaving plugin.
>
> And so on.

I'm 90% on Walter's side here as he's right for the majority of 
common cases, but on the other hand there are plenty of 
situations where the boundary between code error and environment 
error get blurred.