YARR/devel not compiling under CentOS7 because of std::optional
Hi,
I'm struggling in compiling the YARR devel branch in a fresh repo under CentOS7. What I've done after cloning is
- source scl_source enable devtoolset-10 #it's of course installed...
- mkdir Yarr/build ; cd Yarr/build
- cmake3 ../
- make
and it fails on compiling libUtil with:
/tmp/Yarr/src/libUtil/LoggingConfig.cpp:105:18: error: ‘optional’ is not a member of ‘std’ 105 | std::optional<spdlog::level::level_enum> opt_level;
The c++17 flag is used I believe, although cmake tells me that
-- ROOT requires CXXFLAGS: -O2 -g -pipe -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -std=c++11 -pipe -fsigned-char -pthread
so perhaps this relates to the issue.
Any hint @theim ?