Re: [patch #8613] Simplify _AX_CXX_COMPILE_STDCXX_11_testbody

The value is in removing lines of code while maintaining correctness.

If you find now a compiler in the wild that violates the standard with
regard to this define then you can prepend a check against that compiler. I
think you'd still win in terms of code removed. We're talking here about a
check for C++11: There's a standard-conforming, idiomatic way to do that,
that as a bonus is short, simple, and fast.

I think that if a check for support for double right-angle in a template
line is useful, it should be served as a dedicated macro. If a check for
support for && is useful, it should be served as a dedicated macro. But
even then, a macro that checks for C++11 can do its thing without
aggregating all these dedicated little packages for specific C++11
features. It can do its thing with less code and less work than that.


Matan

On Wed, Aug 26, 2015 at 4:27 AM Peter Simons <[email protected]>
wrote:

> Follow-up Comment #4, patch #8613 (project autoconf-archive):
>
> I tend to agree with Peter Johansson in so far that Autoconf traditionally
> checks whether certain features work by *trying them* rather than by
> looking
> at the compiler version, etc. The advantage of these practical tests is
> that
> they tend to produce reliable results for any kind of compiler, whereas the
> latter approach works only for compilers that are known to the macro.
>
> Now, I realize that your patch doesn't suffer from that disadvantage,
> because
> it uses a well known CPP define rather that a list of known compilers.
> Still,
> it's vulnerable to compilers declaring that define incorrectly.
>
> All things considered, I don't quite see what value this refactoring adds.
> If
> there were a specific use case that works with the new code but didn't work
> with the old code, then it would be fine IMHO to put the philosophical
> issue
> aside. I'm just not aware of any such concrete benefits from applying this
> patch?
>
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