Re: [O] babel C, C++, D enhancement

[Thierry Banel]

Le 17/06/2014 19:16, Achim Gratz a écrit :
> Thierry Banel writes:
>> You are right, INT_MAX is the C++ constant to compare to.
>> It is defined in limits.h
>>
>> I'm not sure I want to locate limits.h (where is it ? are there several
>> versions ?),
>> and parse it, all from within Emacs-lisp...
> No, this isn't something you should even try.  The only method that is
> known to work is what autoconf does: compile a program and check the
> output.
Absolutely right.
Or use "getconf INT_MAX" as suggested by Nick Dokos, but this does not
works everywhere.
>> And this will have to be done for all languages (Python, Perl, Java,
>> and so on), not just C++.
> Let's stick with C(++) and solve that problem first, that there is a lot
> of boilerplate code in Babel language support that should be lifted off
> elsewhere is a discussion for another time.
I do agree.

By the way, other languages may not be as tricky.

- Java specifies int to be exactly 32 bits, long to be 64 bits.
  http://en.wikibooks.org/wiki/Java_Programming/Primitive_Types

- Same goes for D.
  http://dlang.org/type.html

- In C++ there is a new specification with types like:
  |int_least32_t| // at least 32 bits
  |int32_t // exactly 32 bits|
  http://en.cppreference.com/w/cpp/types/integer

>> Or we could assume that INT_MAX is always 2147483647.
>> (Which of course is not true).
> You've just made compilers customizable.  For a start, make those
> constants customizable per compiler as well?
>
Thomas S. Dye suggested just that.
Should we throw this detail at the user ?
She will have a hard time figuring out why we bother her with integer size.


Regards
Thierry