Help in compiling C++ code external to UE4 (it's a sort of library)

[FrancescoDeso]

@Bolobolo

Your library needs to be part of an existing module or in its own module.
Copy your source folder to right module folder, regenerate the project files and the build system should be aware of your library.
In order to access types and functions defined in your library from other modules, they need to be exported. You do that by adding the “MODULENAME_API” macro before the type/function name.
Example from the navmesh module :

class NAVMESH_API dtCrowd{...};

Now dtCrowd can be directly accessed by other modules.

Thank you for the explanation, I will consider it.

But it’s not exactly what I would like to do. I don’t want to copy the library code into my UE4 project folder. Instead, I would like to tell UE build system where the library code is located (meaning, outside the project folder: any other place in the filesystem). This would be very useful, since edits applied to the library code are automatically applied for every project that uses that code base. Do you have any idea on how to do that?