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copied!<p>Classes with <code>virtual private</code> base should not be derived from, per <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_closed.html#7" rel="nofollow">this</a> at the C++ SWG. The compiler is doing the right thing (up to a point). The issue is not with the visibility of A from C, it's that C should not be allowed to be instantiated at all, implying that the bug is in the first (default) construction rather than the other lines.</p> <blockquote> <ol> <li>Can a class with a private virtual base class be derived from?</li> </ol> <p>Section: 11.2 [class.access.base]<br> Status: NAD Submitter: Jason Merrill Date: unknown</p> </blockquote> <pre><code>class Foo { public: Foo() {} ~Foo() {} }; class A : virtual private Foo { public: A() {} ~A() {} }; class Bar : public A { public: Bar() {} ~Bar() {} }; </code></pre> <blockquote> <p>~Bar() calls ~Foo(), which is ill-formed due to access violation, right? (Bar's constructor has the same problem since it needs to call Foo's constructor.) There seems to be some disagreement among compilers. Sun, IBM and g++ reject the testcase, EDG and HP accept it. Perhaps this case should be clarified by a note in the draft. In short, it looks like a class with a virtual private base can't be derived from.</p> <p>Rationale: This is what was intended.</p> </blockquote> <p>btw the Visual C++ v10 compiler behaviour is the same as noted in the question. Removing <code>virtual</code> from the inheritance of <code>A</code> in <code>B</code> fixes the problem. </p>

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