C circular dependency

Seems like you shouldn’t need to include anything in any of the files. A forward declaration of the relevant types should be sufficient: #ifndef MapTest_vertex_h #define MapTest_vertex_h struct edgelist; typedef struct { char* name; float x, y; edgelist* edges; // C++ only – not C } vertex; #endif etc. In C coding, you have to … Read more

Circular C++ Header Includes

Is this kind of cross-inclusions are prohibited? Yes. A work-around would be to say that the ifr member of mainw is a reference or a pointer, so that a forward-declaration will do instead of including the full declaration, like: //#include “IFr.h” //not this class IFr; //this instead … class mainw { public: static IFr* ifr; … Read more

What happens when using mutual or circular (cyclic) imports?

If you do import foo (inside bar.py) and import bar (inside foo.py), it will work fine. By the time anything actually runs, both modules will be fully loaded and will have references to each other. The problem is when instead you do from foo import abc (inside bar.py) and from bar import xyz (inside foo.py). … Read more

Circular dependency in Java constructors

The constructor of your class A calls the constructor of class B. The constructor of class B calls the constructor of class A. You have an infinite recursion call, that’s why you end up having a StackOverflowError. Java supports having circular dependencies between classes, the problem here is only related to constructors calling each others. … Read more

Why do circular imports seemingly work further up in the call stack but then raise an ImportError further down?

I think the answer by jpmc26, while by no means wrong, comes down too heavily on circular imports. They can work just fine, if you set them up correctly. The easiest way to do so is to use import my_module syntax, rather than from my_module import some_object. The former will almost always work, even if … Read more

What happens when using mutual or circular (cyclic) imports in Python?

If you do import foo (inside bar.py) and import bar (inside foo.py), it will work fine. By the time anything actually runs, both modules will be fully loaded and will have references to each other. The problem is when instead you do from foo import abc (inside bar.py) and from bar import xyz (inside foo.py). … Read more