On 19/02/2023 22:27, Gero Peterhoff via Boost wrote:
Hi, for more compatibility with existing boost-macros/defines I came up with - see attachment. 1) Is that correct in principle?
These are best dealt with via PR's on Github - preferable one macro at a time and with test cases. See https://www.boost.org/doc/libs/1_81_0/libs/config/doc/html/boost_config/guid... For BOOST_CXXNN_CONSTEXPR: yes there are constexpr updates for each of the last few standards, but I'm having a hard time seeing what the benefit of these macros are over checking __cpp_constexpr directly? BTW we generally only add new macros at the request of an existing boost library.
2) Problem: for BOOST_NO_CXX23_HDR_XXX I use __has_include. However, __has_include is not guaranteed to exist. How about the solution?
We deal with this like this: https://github.com/boostorg/config/blob/ab271393a7f9321d34ca641cc2b042aa0817... It's not trivial, and I would like to have a (released) C++23 compiler to test with before committing to this. John.