--- bar.d

module bar;

​

import foo;

​

class D : C

{

    void example()

    {

        // ok - D inherits from C

        this.fun();

    }

}

​

void example()

{

    auto c = new C;

    // error - can't access C.fun here

    c.fun();

}

​

--- foo.d

module foo;

​

class C

{

    protected void fun()

    {

        import std.stdio: writeln;

        writeln("fun");

    }

}

​

void example()

{

    auto c = new C;

    // ok - C.fun is defined in this module

    c.fun();

}