On Sat, Sep 7, 2019 at 3:11 PM Segher Boessenkool <seg...@kernel.crashing.org> wrote: > > I wouldn't. Please stop using that straw man. I'm not saying version > checks are good, or useful for most things. I am saying they are not. > > Predefined compiler symbols to do version checking (of a feature) is > just a lesser instance of the same problem though. (And it causes its > own more or less obvious problems as well).
That is fair enough, but what are you suggesting we use, then? Because "testing to do X to know if you can do X" cannot work with source code alone and implies each project has to redo this work in its build system for each compiler, plus each project ends up with different names for these macros. The C++20 approach of having standardized macros for major features is way better (whether we have one macro per feature or a __has_feature(X) macro). Note this does not mean we need to take this to the extreme and have a feature-test macro for *every* feature, bugfix or behavior change as a macro. Cheers, Miguel
