Can someone confirm if the attached code doesn't compile intentionally or if this is a bug? I'm sorry for not posting a minimal example but I couldn't figure out how to reduce the problem. It requires Windows (uses ATL::CAdapt and ATL::CComBSTR) and I've tested using VS 2005 and VS2008. This bug manifests when the Reference type has overloaded the address-of operator to return a type not implicitly convertible to Value * (I believe). Changing lines 324-326 in iterator_facade.hpp from: static type make(Reference x) { return implicit_cast<type>(&x); } to: static type make(Reference x) { return implicit_cast<type>(boost::addressof(x)); } and adding the appropriate include makes the attached code compile. Full error log below: 1>c:\dev\vendor\boost\1.37.0\boost\iterator\iterator_facade.hpp(326) : error C2664: 'boost::implicit_cast' : cannot convert parameter 1 from 'BSTR *' to 'ATL::CComBSTR *' 1> Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast 1> c:\dev\vendor\boost\1.37.0\boost\iterator\iterator_facade.hpp(325) : while compiling class template member function 'ATL::CComBSTR *boost::detail::operator_arrow_result<ValueType,Reference,Pointer>::make(Reference)' 1> with 1> [ 1> ValueType=ATL::CComBSTR, 1> Reference=ATL::CComBSTR &, 1> Pointer=ATL::CComBSTR * 1> ] 1> c:\dev\vendor\boost\1.37.0\boost\iterator\iterator_facade.hpp(641) : see reference to class template instantiation 'boost::detail::operator_arrow_result<ValueType,Reference,Pointer>' being compiled 1> with 1> [ 1> ValueType=ATL::CComBSTR, 1> Reference=ATL::CComBSTR &, 1> Pointer=ATL::CComBSTR * 1> ] 1> c:\dev\vendor\boost\1.37.0\boost\iterator\iterator_adaptor.hpp(271) : see reference to class template instantiation 'boost::iterator_facade<Derived,Value,CategoryOrTraversal,Reference,Difference>' being compiled 1> with 1> [ 1> Derived=test::atl::CAdapt_iterator<std::_Vector_iterator<ATL::CAdapt<ATL::CComBSTR>,std::allocator<ATL::CAdapt<ATL::CComBSTR>>>>, 1> Value=ATL::CComBSTR, 1> CategoryOrTraversal=std::random_access_iterator_tag, 1> Reference=ATL::CComBSTR &, 1> Difference=__w64 int 1> ] 1> c:\dev\personal\boost\iterator_adaptor_bug\main.cpp(65) : see reference to class template instantiation 'boost::iterator_adaptor<Derived,Base,Value,Traversal,Reference>' being compiled 1> with 1> [ 1> Derived=test::atl::CAdapt_iterator<std::_Vector_iterator<ATL::CAdapt<ATL::CComBSTR>,std::allocator<ATL::CAdapt<ATL::CComBSTR>>>>, 1> Base=std::_Vector_iterator<ATL::CAdapt<ATL::CComBSTR>,std::allocator<ATL::CAdapt<ATL::CComBSTR>>>, 1> Value=ATL::CComBSTR, 1> Traversal=std::random_access_iterator_tag, 1> Reference=ATL::CComBSTR & 1> ] 1> c:\dev\personal\boost\iterator_adaptor_bug\main.cpp(103) : see reference to class template instantiation 'test::atl::CAdapt_iterator<Iterator>' being compiled 1> with 1> [ 1> Iterator=std::_Vector_iterator<ATL::CAdapt<ATL::CComBSTR>,std::allocator<ATL::CAdapt<ATL::CComBSTR>>> 1> ] Thanks for any insight, --Michael Fawcett