id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
9799	polymorphic_downcast does not support virtual inheritance	Camille Gillot <k1000.jlo@…>	No-Maintainer	"The following code barks at compilation :
{{{#!cpp
#include <boost/cast.hpp>

class A {
public:
  virtual ~A();
};

class B
: public A
{};

class C
: public virtual A
{};

int main() {
  A* b = new B; A* c = new C;
  B* bb = boost::polymorphic_downcast<B*>(b); // Fine
  C* cc = boost::polymorphic_downcast<C*>(c); // Error

  delete b; delete c;
  return 0;
}
}}}

static_cast cannot handle downcast from or through a virtual base class, dynamic_cast must be used instead.
A fix would be to test the case of virtual base class with boost::is_virtual_base_of and dispatch the two cases.

Here is a patch doing it."	Patches	closed	To Be Determined	utility	Boost 1.54.0	Problem	wontfix