Array as an argument, ambiguous behaviour.

[Cooler]

On Thursday, 30 January 2014 at 09:26:56 UTC, Stanislav Blinov 
wrote:
> On Thursday, 30 January 2014 at 09:14:43 UTC, Cooler wrote:
>
>> Please stop explain me how fun3() works. I know that.
>> One of the main idea of D is that things must work as planned, 
>> or would not compile at all. First and second variants follow 
>> this idea. But fun3() can work not as planned on the caller 
>> side (depends on fun3() body's implementation).
>> The question again - may be prohibit fun3() variant? If we 
>> prohibit it, what use cases we could not implement with fun1() 
>> and fun2()?
>
> Goodness... You've been shown this use case like a zillion 
> times already: the caller manages her buffer, fun3() is allowed 
> to change contents, but not reallocate caller's buffer.
>
> fun1() can't provide that (const), fun2() cannot either, 
> because it explicitly allows reallocation (ref). This behavior 
> is only provided by fun3().
>
> So it's either that, or indeed cases of "I don't care about 
> this array", which Maxim Fomin has mentioned.

May be I am dumb...
If "I don't care about this array", I can use any of fun1() or 
fun2().

Can you formulate contract to fun3()? Something like "Change 
content of an array, but if you need to change the size - don't 
do it!" Do you think so?