Compiler.h

Can h files be compiled independently?

If these .h files are indeed typical C-style header files (as opposed to being something completely different that just happens to be named with .h extension), then no, there's no reason to "compile" these header files independently.

How to compile and Link C++ files using gcc compiler notation?

Since gcc compiler notation for c++ file is g++, we can compile and link the files using options '-g' and '-Wall' are for debugging info and getting warning for errors.

What is compiler explorer?

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Compiler Explorer is an interactive online compiler which shows the assembly output of compiled C++, Rust, Go (and many more) code.

C header file

conio.h is a C header file used mostly by MS-DOS compilers to provide console input/output.
It is not part of the C standard library or ISO C, nor is it defined by POSIX.

Canadian computer scientist

Paul H.
Cress (1939–2004) was a Canadian computer scientist.