c++11 flag is not added in configure

[Yanpas]

g++ -DHAVE_CONFIG_H -I../include -I../include -I/usr/include/postgresql -g -O2 -Wno-long-long -fvisibility=hidden -fvisibility-inlines-hidden -MT binarystring.lo -MD -MP -MF .deps/binarystring.Tpo -c binarystring.cxx -fPIC -DPIC -o .libs/binarystring.o - one of the lines that was executed. autotools must explicitly add -std=c++0x

[jtv]

Recent gcc versions compile C++14 by default. If you're using an older version, add the flag to the "configure" command line:

./configure CXXFLAGS='-std=c++11'

(Of course you can also say c++14 to get a more modern dialect.)

I could add this option in the configure script, but that opens the door to questions like: What if your compiler uses a different option for this? Which C++ versions does your compiler version support? What if you want a different C++ version? What if the compiler defaults to a newer version?

So the best solution, I think, is to set this option in your "configure" until your systems are upgraded to more recent compiler versions. I was tempted to make C++14 the minimum, but I kept it to C++11 for now to minimise these problems...

[Yanpas]

Thanks, didn't know. I barely know autotools but CMake has CXX_STANDARD option. If there is something similar you may add this to configure script.

[jtv]

I don't know of anything like that, but now that you bring it up, I did notice something strange: on an older gcc, if I passed -std=c++17 or -std=c++20, the command line would still say -std=c++14 — I guess maybe that was the newest standard which that compiler supported.

So probably there is some logic for picking the C++ standard in there. But I'm sort of afraid to mess with it! :)

[jtv]

I just got "configure" to add the C++11 option. This does mean that autogen.sh now requires the autoconf-archive package.