When class A has protected variables, class B inherits from A and class C inherits from B, how do you access the protected variables from class A in C

Question

Sorry about the wordy title, I don't know how to phrase it more concisely.

The error I get is 'identifier "x" is undefined'

I tried doing class C : public B, public A but that didn't seem to work.

My code looks like this at the moment:

class A
{
protected:
    float x;
};
class B : public A
{};
class C : public B
{
    float y = 1 + x; 
    // Error: identifier "x" is undefined
};

I can access the protected variables with no problems in class B, I only get the error when I try to access them in class C.

Answer 1

When class A has protected variables, class B inherits from A and class C inherits from B, how do you access the protected variables from class A in C

You access them in the same way as you would access them in B (so long as the inheritance isn't private). There is no difference with how long the inheritance chain is.

The example program is well-defined since C++11 where default member initialisers were introduced.