Template constraints error messages using cputs()

[BCS]

Hello bearophile,

> BCS:
> 
>> How is pragma(msg,) buggy? It does exactly what it's supposed to do.
>> Unless you can point to a deficiency that it has and something that
>> fixes it. I see no reason to consider dumping it.
>> 
> The thing it is supposed to do is not useful enough,

I dissagree. Strongly.

> as I have explained in my bug report/enhancement request.

Link: http://d.puremagic.com/issues/show_bug.cgi?id=3952

All the issues you address up to where you propose ctputs are bugs in DMD, 
not pragma(msg,...) as for ctputs as a /replacement/ see my replay to the 
bug.

> And even if you want
> to keep it, it's buggy & messy anyway, because it accepts as input
> things that it is not able to digest correctly. It is currently buggy,
> and I see no reason to keep it when there is a better replacement. I
> don't understand what people as you see good in pragma(msg), I think
> you are just mistaken or you have not used it often enough yet.

With regards to that, I have used it quite a lot so either you are just flat 
wrong or what you are talking about is something very esoteric that requiters 
huge amounts of experience to even begin to notice.

While you may be able to convince me there are things that it can't do that 
are useful and maybe even that there are things that it does that it shouldn't, 
you will not convince me that what it currently does is less than /very useful/. 


My minimum requirements for a pragma(msgm...) replacement would be that it 
take any expression that results in an immutable(char[]) and, at compile 
time (and only compile time) during the semantic pass (while the code is 
processed, not evaluated) output the string.
 
The major cases where your ctputs fails on this are inside a function that 
can be evaluated via CTFE:
- If placed in a RT loop it could be evaluated to many times.
- If placed in a code path that isn't hit via CTFE, it never outputs anything.
- If the function gets run at RT, then you need to add a guard to prevent 
it from generating output at RT.

-- 
... <IXOYE><