What should go into an .h file?
c++, header-files
Solution
Header files (`.h`) are designed to provide the information that will be needed in multiple files. Things like class declarations, function prototypes, and enumerations typically go in header files. In a word, "definitions".
Code files (`.cpp`) are designed to provide the implementation information that only needs to be known in one file. In general, function bodies, and internal variables that should/will never be accessed by other modules, are what belong in `.cpp` files. In a word, "implementations".
The simplest question to ask yourself to determine what belongs where is "if I change this, will I have to change code in other files to make things compile again?" If the answer is "yes" it probably belongs in the header file; if the answer is "no" it probably belongs in the code file.
Problem
When dividing your code up into multiple files, what exactly should go into an `.h` file and what should go into a `.cpp` file?