feature for C++ standards compliance

From: Robert Ramey (ramey_at_[hidden])
Date: 2021-02-25 18:33:40

The serialization library is compatible with C++03 (and likely 98).  And 
is tested regularly with C++ compilers with the -std switch set to this 
mode.  The recent changes to the math library have broken about 5 tests 
in the serialization library.  Since this breakage is in a few tests 
only and not in the library itself, I'd like to suppress these tests 
when the being tested with a C++03 compiler.  I've suppressed tests 
which are conditional on C++ features which are not supported and this 
has worked well for my purposes.  I'd like to do the same for a couple 
of tests which are conditional on usage of the math library and 
standards versions < C++11.  Any B2/CMake experts want to help an old 
guy out?