Multiple inheritance without virtual functions in c++

Question

I came across the diamond problem and found different solutions for different cases with a single diamond. However I couldn't find a solution for 'chained' diamonds. According to the structure: yes, I want to have multiple baseclasses everytime, so virtual inheritance isn't a solution (is it even called diamond then?). I also wanted to avoid get/set-functions for every middle-layer of a diamond. ``` p p | | k k \ / s class parent { int val; }; class kid1 : public parent {}; class kid2 : public parent {}; class school : public kid1, public kid2 {}; ``` Accessing val in the parent class works now like follows: ``` school* s = new school; s->kid1::val=1; // works ``` But what about the next 'chained' diamond: ``` p p p p | | | | k k k k \ / \ / s s | | c c \ / w class country1 : public school {}; class country2 : public school {}; class world : public country1, public country2 {}; ``` Accessing val via: ``` world* w = new world; w->country1::kid1::val=1; // error ``` results in: ``` erro…

Accepted Answer

`s->kid1::val` does not mean "`val` from the `kid1` subobject". It's just a name qualified by the type (not the subobject) that contains it.

I don't know why `country1::kid1` is even accepted at all, but apparently it's a typedef for `::kid1`. Two data members in `world` both have the qualified name `::kid1::val`.

What you want is:

```
world* w = new world;
country1* const c1 = world;
c1->kid1::val = 1;
```

Multiple inheritance without virtual functions in c++

Solution

Problem