This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112e. See for the official list.


747. Access of protected base classes

Section: 11.8.3  [class.access.base]     Status: dup     Submitter: Sam Saariste     Date: 18 November, 2008

Consider the following example:

    struct B { void f(){} };
    class N : protected B { };

    struct P: N { friend int main(); };
    int main() {
          N n;
          B& b = n; // R

This code is rendered well-formed by bullet 3 of 11.8.3 [class.access.base] paragraph 4, which says that a base class B of N is accessible at R if

This provision circumvents the additional restrictions on access to protected members found in 11.8.5 [class.protected] — main() could not call B::f() directly because the reference is not via an object of the class through which access is obtained. What is the purpose of this rule?

Rationale (April, 2010):

This is a duplicate of issue 472.