Directive #include
To use the same text or subroutines in different program files, it is convenient to put the program text in header files. Usually in C++, such files are given an extension.h or .hpp.
Example.
#include "my_heading.hpp"
At this point in the program, the code located in the my_heading.hpp file will be inserted.
Unlike a regular program file, the code in the plug-in file should not contain the main() function
If for some reason the file is not found during execution, then there will be an error message.
To include a file from a directory that lies above the one in which the current cpp executable file is located, you can specify a relative path:
#include "..\\my_heading.hpp"