<code> struct nullptr_t { nullptr_t() : ptr_(0) {} // pointer template < typename T > operator T*() const { return (T*)0; } // function pointer template < typename R > struct typedef_fun_ptr { typedef R (*type)(); }; template < typename R > operator typename typedef_fun_ptr<R>::type () const { return (typedef_fun_ptr<R>::type)0; } // arg1 ... arg10 // for member function pointer (doesn't works) template < typename C, typename R > struct typedef_memfun_ptr { typedef R (C::*type)(); }; template < typename C, typename R > operator typename typedef_memfun_ptr<C,R>::type () const { return (typedef_memfun_ptr<C,R>::type)0; } // arg1 ... arg10 private: void* ptr_; }; const nullptr_t nullptr; </code> this is my code for nullptr in C++98. it works for normal pointers, function pointers but not for member pointers. anybody knows why it doesn't works? sample code is follows <code> int* p = nullptr; std::string* s = nullptr; void* vp = nullptr; assert( p == nullptr ); assert( s == nullptr ); assert( sizeof(nullptr) == sizeof(void*) ); // int i = nullptr; // compile-time error: ok // function pointer int (*fptr1)() = nullptr; void* (*fptr2)() = nullptr; int (nullptr_test::*memfunp2)() = nullptr.get_nullptr<nullptr_test,int>(); int (nullptr_test::*memfunp3)() = nullptr; // don't works </code> the error message is <error_msg> 1>d:\_work\qoom-sr\qoomserver\trunk\worldserver\asioserver \win_main.cpp(162) : error C2440: 'initializing' : couln't convert from 'const nullptr_t' to 'int (__thiscall nullptr_test::* )(void)' </error_msg>
