Re: no + or - defined for fixed point types in Standard, why ?

[Robert Eachus <rieachus@comcast.net>]

On Wednesday, January 24, 2018 at 8:31:33 PM UTC-5, guyclaud...@gmail.com wrote:
> > As I said, you can turn off warnings if it bothers you.  I think if you look through the GNAT sources, there are a number of places where they do that.  As a programming practice, I like it.  It says that the programmer knows that the compiler won't like this, but I want to do it anyway.
> 
> I wouldn't have thought reading that from an Ada user 0_0
> I don't think I'm nearly as wise as people who wrote the compiler. Even if I had been a qualifier programmer, I would think the same and abide by the conventions as much as I could. I'm too conservative in general to go against habits without due reasons or ways to do otherwise.
> 
> > function Test is
> > begin if false then return; end if; end Test;
> >
> 
> it says the first line lacks a "return" statement, which even I can see... why writing such a thing ? Looks like a piece of C, with its void function, or whatever they call that. It's raising hairs on my shoulder, really.

 function Test return Integer is
 begin if false then return 6; end if; end Test;

Oops! wrong test case, try this:


 function Test3 return Integer is
 begin if false then return 6; end if; end Test3;

You should get at least one warning, and no errors.  Provide a Boolean parameter instead of false:

 function Test4 (X: Boolean) return Integer is
 begin if X then return 6; end if; end Test4;

And you should be down to one warning.

Compiler writers have thousands of these ugly things and sometimes what the compiler guesses you intended is good for a laugh.  Some test cases are regression tests collected from bug reports--you never want to reintroduce an old bug.  Others are designed to thoroughly test all the ways you imagine that a new feature can get misused.