The plot thickens: class Universe : std::tr1::enable_shared_from_this<Universe> { const int answer; public: Universe (int a) : answer(a) {} std::string get_answer() const; void get_nothing() {} virtual void blahblah(); // !!! }; Universe u1(42); foo (&Universe::get_answer, &u1); Regarding my previous post on the definitions of foo, if the class inherits from enable_shared_from this *and* contains a virtual function, then this call to foo doesn't work, giving funny template errors in boost::result_of. 2>E:\boost_1_49\boost/utility/result_of.hpp(82): error C2825: 'F': must be a class or namespace when followed by '::' 2> E:\boost_1_49\boost/utility/result_of.hpp(90) : see reference to class template instantiation 'boost::detail::result_of_nested_result<F,FArgs>' being compiled 2> with 2> [ 2> F=std::basic_string<char,std::char_traits<char>,std::allocator<char>> (__thiscall thread_pool_tests::Universe::* &)(void) const, 2> FArgs=std::basic_string<char,std::char_traits<char>,std::allocator<char>> (__thiscall thread_pool_tests::Universe::* &(thread_pool_tests::Universe *))(void) const 2> ] 2> E:\boost_1_49\boost/utility/detail/result_of_iterate.hpp(33) : see reference to class template instantiation 'boost::detail::tr1_result_of_impl<F,FArgs,HasResultType>' being compiled 2> with 2> [ 2> F=std::basic_string<char,std::char_traits<char>,std::allocator<char>> (__thiscall thread_pool_tests::Universe::* &)(void) const, 2> FArgs=std::basic_string<char,std::char_traits<char>,std::allocator<char>> (__thiscall thread_pool_tests::Universe::* &(thread_pool_tests::Universe *))(void) const, 2> HasResultType=false 2> ] 2> E:\boost_1_49\boost/utility/detail/result_of_iterate.hpp(75) : see reference to class template instantiation 'boost::tr1_result_of<F>' being compiled 2> with 2> [ 2> F=std::basic_string<char,std::char_traits<char>,std::allocator<char>> (__thiscall thread_pool_tests::Universe::* &(thread_pool_tests::Universe *))(void) const 2> ] 2> threadpoolTest.cpp(78) : see reference to class template instantiation 'boost::result_of<F>' being compiled 2> with 2> [ 2> F=std::string (__thiscall thread_pool_tests::Universe::* &(thread_pool_tests::Universe *))(void) const 2> ] 2>E:\boost_1_49\boost/utility/result_of.hpp(82): error C2516: 'F' : is not a legal base class 2> E:\boost_1_49\boost/utility/result_of.hpp(90) : see declaration of 'F' 2>E:\boost_1_49\boost/utility/result_of.hpp(82): error C2143: syntax error : missing ',' before '::' 2>E:\boost_1_49\boost/utility/result_of.hpp(82): error C2903: 'result' : symbol is neither a class template nor a function template 2>E:\boost_1_49\boost/utility/result_of.hpp(82): error C2039: 'result' : is not a member of '`global namespace'' 2>E:\boost_1_49\boost/utility/result_of.hpp(82): error C2504: 'result' : base class undefined 2>E:\boost_1_49\boost/utility/result_of.hpp(82): error C2143: syntax error : missing ',' before '<' 2>threadpoolTest.cpp(78): error C2780: 'boost::unique_future<boost::result_of<F(T0,T1)>::type> foo(F &&,A1 &&,A2 &&)' : expects 3 arguments - 2 provided 2> V⋯.h(243) : see declaration of 'vst::async' 2>threadpoolTest.cpp(78): error C2893: Failed to specialize function template 'boost::unique_future<boost::result_of<F(T0)>::type> vst::async(F &&,A1 &&)' 2> With the following template arguments: 2> 'std::string (__thiscall thread_pool_tests::Universe::* &)(void) const' 2> 'thread_pool_tests::Universe *' 2>threadpoolTest.cpp(78): error C2780: 'boost::unique_future<R> vst::async(F &&)' : expects 1 arguments - 2 provided 2> with 2> [ 2> R= 2> ]