[CJefferson]

The only modern problem with switching to C99 is Visual Studio on Windows. You have 2 sensible choices:

1) Use clang to build on Windows.

2) Use the subset of C99 which is implemented in Visual Studio (which also requires compiling as C++, which isn't that difficult to handle).

[gdxhyrd]

3) Use C++17 with minimal features. This gives you a lot of needed libraries built-in and it is better supported than C99 (due to Windows).

[jhayward]

> Use C++17 with minimal features

To paraphrase JWZ, "now you have N+M problems"

[gdxhyrd]

C++17 is a very close language to C18 if you avoid exceptions, classes and templates.