To get correct __cplusplus value (e.g., 201703L ), you must use /Zc:__cplusplus in VS 2019. Without it, it defaults to 199711L .
// New: template<typename T> void foo(T t) ::declared(t); visual c++ 2015 to 2019
Historically, each Visual Studio release required a separate runtime. Starting with Visual Studio 2015, Microsoft merged these into a single . To get correct __cplusplus value (e