These compilers will become the default for building packages in
conda-forge. One notable change in gcc 10 is that the -fopenmp`` flag in
FFLAGSis dropped. In clang 12,
-std=c++14explicit flag has been dropped from
CXXFLAGS, as it is the default compilation mode for clang 12. In gcc 11, the default is
-std=gnu++17`. In clang>=12 and gcc>=11,
we will not provide an explicit C++ standard, and will defer to the
compiler default.