To 2019 - Visual C++ 2015

Mixing v140 .obj with v142 .obj that use different C++ standard versions. Fix: Recompile all or ensure identical /std:c++ flags.

One significant point of friction during this period was the C++ ABI (Application Binary Interface). visual c++ 2015 to 2019

// Old (may compile in 2015): template<typename T> void foo(T t) undeclared(t); // error now Mixing v140

Installing the latest 2022 version automatically includes support for applications built with 2015, 2017, or 2019 tools. void foo(T t) undeclared(t)