Can the C preprocessor be used to tell if a file exists?

Question

I have a very large codebase (read: thousands of modules) that has code shared across numerous projects that all run on different operating systems with different C++ compil

Answer 1

Contrary to some claims here and on the internet, Visual Studio 2015 does NOT support the __has_include feature - at least according to my experience. Tested with Update 3.

The rumors may have arisen from the fact that VS 2017 is also referred to as "Version 15"; VS 2015 is instead referred to as "Version 14". Support for the feature seems to have been officially introduced with "Visual Studio 2017 Version 15.3".