Re: Compile error in latest repository tip

[Daniel J Sebald]

On 03/03/2016 05:57 PM, Mike Miller wrote:
> On Thu, Mar 03, 2016 at 17:01:43 -0600, Daniel J Sebald wrote:
> > That configuration option seems to make compilation proceed, thanks. Would
> > it be possible to make "gnu++0x" be assigned to -std as part of the
> > configure process?  -std=gnu11 is being tested, so if that fails it
> > shouldn't be difficult to test if -std=gnu++0x fails as a fallback.
>
> It is already doing so, check your config.log again. The reason it fails
> is because your version of gcc is not C++11-compliant enough, according
> to configure, even with the correct -std option.

I see it is tested individually:

for ac_arg in '' -std=gnu++11 -std=c++11 -std=gnu++0x -std=c++0x 
-qlanglvl=extended0x -AA
do
  CXX="$ac_save_CXX $ac_arg"
  if ac_fn_cxx_try_compile "$LINENO"
then :
  ac_cv_prog_cxx_cxx11=$ac_arg
fi
rm -f core conftest.err conftest.$ac_objext
  test "x$ac_cv_prog_cxx_cxx11" != "xno" && break
done

So, my version of gcc isn't C++11 compliant enough to past the tests 
within configure with the gnu++0x option (so the gnu++0x option is 
excluded) but it turns out that the compiler is C++11 compliant enough 
to work for whatever portions of C++11 that Octave source code is using. 
 Here's the man entry for g++:

           gnu++0x
               GNU dialect of -std=c++0x. This option enables experimental
               features that may be removed in future versions of GCC.

OK, there was enough experimental stuff in my version of the compiler, 
as luck would have it.  Got it.

Dan