31 Aug
2018
31 Aug
'18
6:27 p.m.
[Robert]
How exactly will the changing VS standard header files compile without C++17 being the 15.9.x default?
VS 2017 15.9 will *not* change the Standard mode default to C++17. It will remain at C++14 for that update. MSVC's STL supports being compiled in both C++14 and C++17 mode; we sense the Standard mode and adapt our code accordingly. We use "if constexpr" internally to improve throughput because MSVC and Clang support it in C++14 mode with a disable-able warning. (We have an escape hatch, which we reserve the right to remove at any time without notice.) Stephan T. Lavavej Principal Software Engineer, Visual C++ Libraries