precisely (see the description of --enable-build-type for the default
values):
+ o --enable-cxx-mode=VALUE can be used to select a C++ standard, for
+ example --enable-cxx-mode=11. The default is to try C++14, and then
+ C++11.
+
o --enable-optimization=VALUE enables you to set optimization to a
higher level than the default, for example --enable-optimization=-O3.