Re: Selecting a C++ standard

[Harlan Stenn]

Adrian Bunk writes:
> On Sat, Oct 27, 2012 at 02:05:01PM -0700, Harlan Stenn wrote:
> > Paul Eggert writes:
> > > For C, we're deprecating the "I want version X"
> > > macros in favor of just AC_PROG_CC_STDC, which says
> > > "I want the latest version".  You might want to do
> > > that for C++ to, as it's more the Autoconf Way.
> > 
> > This is good news/bad news, IMO.
> > 
> > It means that if I want to do compliance testing to make sure a package
> > builds under a variety of compilers I have to do work "outside" of
> > autoconf to make that happen.
> 
> I don't understand the problem you are trying to describe.

If I have software that is supposed to be buildable by C89 or later,
then this software must be built using a variety of (versions of)
compilers to make sure  this is true.  A developer using a more recent C
compiler may unknowlingly add code that requires a newer compiler.

> > It also means that the installed STDC may be too old for what I want I
> > have to do other checks to make sure the installed STDC is sufficient.
> > 
> > It might be good to be able to say "at least C89".
> 
> Current autoconf git gives you "as high as possible".

Sure, and as I've been saying, that's not always what  somebody wants.

Separate "mechanism" from "policy".

You seem to be saying your policy will work for everybody...

> "at least C89" can anyway be assumed today.

Probably...

> How to test for what you need (also allowing you to abort configure if 
> something you need is not supported) is a separate issue.

There is a difference between ignoring a problem and making a problem
you don't have harder to solve for those folks who *do* have to think
about it.

H