General question about iOS app structure and mixing Obj-C, standard C, C++ etc

An iOS app would contain Objective-C / Cocoa, traditional C and possibly C++. Is it a good practice to keep these physically separated (in different source 开发者_如何学Pythonfiles)? I know an .mm file is actually all of these at once but I'm looking for opinions as to how to structure these.

One of many possible answers is make project which contain main program and several static(I don't know about dynamic libs support) libraries (different parts of application) to combine them into one application later