Complete Modern C++ - Feature Test Macros

The video tutorial explains the use of feature test macros in C programming, focusing on the 'has include' macro to check the availability of header files. It discusses the transition from experimental to standardized implementations, particularly with the C-17 file system API. The tutorial provides a practical example of using the macro, handling deprecated headers, and checking platform-specific files. It also introduces C20 feature test macros, which help identify the availability of specific C features.

Describe the significance of checking for platform-specific header files.

What are feature test macros and how do they function in C20?

What does the output of the feature test macros indicate?