c++/2330: static_cast<>() to a private base is allowed

c++/2330: static_cast<>() to a private base is allowed

[philippeb]

>Number:         2330
>Category:       c++
>Synopsis:       static_cast<>() to a private base is allowed
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Mar 20 10:26:01 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     gcc
>Release:        2.95.3
>Organization:
>Environment:
Debian Linux (Woody) on Intel
>Description:
static_cast<>() from a derived type to its private base is 
allowed, but shouldn't. dynamic_cast<>() is okay on its side.
>How-To-Repeat:
#include <iostream>

struct A
{
    void foo() { std::cout << __PRETTY_FUNCTION__ << std::endl; }
};

struct B : private A
{
};

int main()
{
    B b;
    static_cast<A &>(b).foo();
}
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:

Re: c++/2330: static_cast<>() to a private base is allowed

[Wolfgang Bangerth]

The following reply was made to PR c++/2330; it has been noted by GNATS.

From: Wolfgang Bangerth <bangerth@ticam.utexas.edu>
To: gcc-gnats@gcc.gnu.org
Cc:  
Subject: Re: c++/2330: static_cast<>() to a private base is allowed
Date: Fri, 8 Nov 2002 09:07:23 -0600 (CST)

 This problem persists. It also appears with a C-style cast like 
 (Base*)derived_object, see PR 8500.
 
 W.
 
 -------------------------------------------------------------------------
 Wolfgang Bangerth              email:           bangerth@ticam.utexas.edu
                                www: http://www.ticam.utexas.edu/~bangerth