Code structure

There are different opinions on how to best organise C++ code, but a common guiding principle is that too much code repetition should be avoided. Here we present one standard approach to structuring C++ code:

• Put useful functions that you’ll need again and again in dedicated source files (.cpp). Place these source files in a folder named src.

• For each such source file, write a header file (.hpp) that only contains the function declarations. Place these header files in a folder named include.

• In your main program(s), simply #include the header file with the relevant function declaration and use the function in your main program.

Keep in mind that for this to work, the .cpp files in src/ must be compiled and linked to the main program – see the example compilation + linking commands in the next section.

With this code structure you can typically write reasonably short and clear main programs that each just do a small number of tasks (e.g. computes one number of interest or performs one particular simulation), since the common code needed by all the main programs have been placed in some other files.

You can find an example illustrating this structure here.