I was working around with inheritance in C . To my knowledge if you don't specify, B will always inherit private from A.

So why does this code work:

struct A {};
struct B : A {};

int main(void)
{
    A b = B();
    return 0;
}

But this creates the "A is an inaccessible Base of B" error:

struct A {};
struct B : private A {};

int main(void)
{
    A b = B();
    return 0;
}

I would expect them to be the same?

CodePudding user response：

Private inheritance is the default if the derived class is defined using the word class.

If you create it using struct, then inheritance is public by default.

CodePudding user response：

From cppreference:

A class defined with the keyword struct has public access for its members and its base classes by default.

A class defined with the keyword class has private access for its members and its base classes by default.

Or from Derived Classes documentation

If access-specifier is omitted, it defaults to public for classes declared with class-key struct and to private for classes declared with class-key class.

The above quotes explain the behavior of your program.