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copied!<p>There is no problem with overloading or inheritance:</p> <pre><code>#include <iostream> #include <memory> namespace { struct A { virtual void f() { std::cout<<"inside A's f()\n"; } template <typename T> void f(T t) { std::cout<<T::i<<'\t'; this->f(); } }; struct B : A { void f() { std::cout<<"hello\t"; A::f(); } }; struct C { static const unsigned int i = 5; }; struct D { enum { i = 6 }; }; } int main() { std::auto_ptr<A> b(new B()); b->f(C()); b->f(D()); } </code></pre> <p>Works correctly. On the other hand, the smallest example I can find that exhibits your problem does not have inheritance or overloading:</p> <pre><code>#include <iostream> namespace { struct A { template<class C> void print(C c) { c.print(); } }; } int main() { struct B { void print() { std::cout << "whee!\n"; } }; A a; B b; a.print(b); } </code></pre> <p>Note that if <code>struct B</code> is defined in a namespace (whether it's an unnamed namespace, or a completely different namespace, or the global namespace) instead of inside <code>main()</code> that this compiles without error.</p> <p><strike>I don't know enough of the standard to say if this is a bug, but it appears to be one. I've gone ahead and <a href="http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39770" rel="nofollow noreferrer">reported it to the GCC bug database</a>.</strike></p> <hr> <p>And here's your answer from the GCC developers (from the link above): "Local classes cannot be template arguments."</p> <p>So the code is broken. <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2003/n1427.pdf" rel="nofollow noreferrer">Not that it's a bad idea</a>. In fact, C++0x removes this restriction.</p> <p>I noticed the line</p> <blockquote> <p>Note that the code works in GCC if I explicitly cast vpc to (RenFlexibleVertexPc *)</p> </blockquote> <p>And since <code>RenFlexibleVertexPc</code> is not a local class this makes sense. However <code>Pc</code> is a local class/struct, so it is not allowed.</p>

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