C++ Programming :: Template question


	Template question I have a template class declared like this: template <class T> class CKineStore { public: CKineStore(void) {}; virtual ~CKineStore(void) {}; public: void Insert(CKineTypes::ECKineType type, T&); private: typedef std::pair <CKineTypes::ECKineType, T> m_pair; typedef std::map <CKineTypes::ECKineType, T> m_map; }; template <class T> void CKineStore<T>::Insert(CKineTypes::ECKineType type, T& t) { m_map.insert(m_pair(type, t)); } If I dont call Insert() it compiles okay, but when I call it I get an unresolved external symbol error. What am I doing wrong? Thanks, B On Jun 3, 6:36 pm, Bryan <b@no.spam.com> wrote: - Hide quoted text - > I have a template class declared like this: > template <class T> > class CKineStore > { > public: > CKineStore(void) {}; > virtual ~CKineStore(void) {}; > public: > void Insert(CKineTypes::ECKineType type, T&); > private: > typedef std::pair <CKineTypes::ECKineType, T> m_pair; > typedef std::map <CKineTypes::ECKineType, T> m_map; > }; > template <class T> void CKineStore<T>::Insert(CKineTypes::ECKineType > type, T& t) > { > m_map.insert(m_pair(type, t)); > } > If I dont call Insert() it compiles okay, but when I call it I get an > unresolved external symbol error. What am I doing wrong? > Thanks, > B You didn't provide much information about CKineTypes, nonetheless, try: void Insert( typename CKineTypes::ECKineType type, T&); template <class T> void CKineStore<T>::Insert( typename CKineTypes::ECKineType type, T& t) {} Note the use of "typename" ma740988 wrote: > You didn't provide much information about CKineTypes, nonetheless, > try: > void Insert( typename CKineTypes::ECKineType type, T&); > template <class T> > void CKineStore<T>::Insert( > typename CKineTypes::ECKineType > type, T& t) > {} > Note the use of "typename" Sorry, CKineTypes is just an enum. Still the same error though. I did this: template <class T> class CKineStore { ... public: void Insert(typename CKineTypes::ECKineType type, T&); ... }; And in the cpp file: template <class T> void CKineStore<T>::Insert(typename CKineTypes::ECKineType type, T& t) { insert(m_pair(type, t)); } Im not very experienced with templates obviously, what am I missing? B Bryan wrote: > I have a template class declared like this: > template <class T> > class CKineStore > { > public: > CKineStore(void) {}; Why the void? This isn't C. > virtual ~CKineStore(void) {}; > public: > void Insert(CKineTypes::ECKineType type, T&); What is CKineTypes and its ECKineType? Why this need for hungarian notation (prefixing type names with a C and E)? > private: > typedef std::pair <CKineTypes::ECKineType, T> m_pair; > typedef std::map <CKineTypes::ECKineType, T> m_map; Here, m_map is defined as a type. > }; > template <class T> void CKineStore<T>::Insert(CKineTypes::ECKineType > type, T& t) > { > m_map.insert(m_pair(type, t)); Here, you are using m_map, the type, as an object. > } > If I dont call Insert() it compiles okay, but when I call it I get an > unresolved external symbol error. What am I doing wrong? Try removing the typedef in m_map's definition. -- rbh Robert Bauck Hamar wrote: > Bryan wrote: >> I have a template class declared like this: >> template <class T> >> class CKineStore >> { >> public: >> CKineStore(void) {}; > Why the void? This isn't C. Dunno. Visual studio 2005 sticks it in there by default. >> virtual ~CKineStore(void) {}; >> public: >> void Insert(CKineTypes::ECKineType type, T&); > What is CKineTypes and its ECKineType? Why this need for hungarian > notation (prefixing type names with a C and E)? CKineTypes is actually not hungarian, but you are right ECKineType is. I am just used to it I suppose. >> private: >> typedef std::pair <CKineTypes::ECKineType, T> m_pair; >> typedef std::map <CKineTypes::ECKineType, T> m_map; > Here, m_map is defined as a type. You are right, this is a typo on my part. It is actually: std::map <CKineTypes::ECKineType, T> m_map; This is a larger class, and I removed some portions for brevity. - Hide quoted text - >> }; >> template <class T> void CKineStore<T>::Insert(CKineTypes::ECKineType >> type, T& t) >> { >> m_map.insert(m_pair(type, t)); > Here, you are using m_map, the type, as an object. >> } >> If I dont call Insert() it compiles okay, but when I call it I get an >> unresolved external symbol error. What am I doing wrong? > Try removing the typedef in m_map's definition. Error seems to persist... the errors you pointed out are valid- not complaining at all, thanks for pointing them out. But the error I initially reported is a signature issue. The declaration of the Insert function doesnt match any known definition, so the unresolved external symbol error shows up. I can, in fact do this: template <class T> class CKineStore { ... public: void Test(); ... }; template <class T> void CKineStore<T>::Test() { } And I get the same error, unresolved external symbol. On Jun 4, 1:52 am, Bryan <b@no.spam.com> wrote: > And in the cpp file: > template <class T> > void CKineStore<T>::Insert(typename CKineTypes::ECKineType type, T& t) > { > insert(m_pair(type, t)); > } > Im not very experienced with templates obviously, what am I missing? Try putting everything in the same file. v.r.mari@gmail.com wrote: > On Jun 4, 1:52 am, Bryan <b@no.spam.com> wrote: >> And in the cpp file: >> template <class T> >> void CKineStore<T>::Insert(typename CKineTypes::ECKineType type, T& t) >> { >> insert(m_pair(type, t)); >> } >> Im not very experienced with templates obviously, what am I missing? > Try putting everything in the same file. That did it! Thanks, B - Hide quoted text - Bryan wrote: > Robert Bauck Hamar wrote: > But the error I initially reported is a signature issue. The > declaration of the Insert function doesnt match any known definition, so > the unresolved external symbol error shows up. > I can, in fact do this: > template <class T> > class CKineStore > { > ... > public: > void Test(); > ... > }; > template <class T> > void CKineStore<T>::Test() > { > } > And I get the same error, unresolved external symbol. Compiles with my compiler, but I use g++. The only explanation I can think of, is that the compiler can't see the definition of CKineStore<T>::Test(). The definition is, of course, included together with the CKineStore class declaration? Then again, it's five in the morning here, so I'm beginning to feel tired. -- rbh On Jun 4, 6:08 am, Robert Bauck Hamar <hamro@yahoo.no> wrote: - Hide quoted text - > Bryan wrote: > > Robert Bauck Hamar wrote: > > But the error I initially reported is a signature issue. The > > declaration of the Insert function doesnt match any known definition, so > > the unresolved external symbol error shows up. > > I can, in fact do this: > > template <class T> > > class CKineStore > > { > > ... > > public: > > void Test(); > > ... > > }; > > template <class T> > > void CKineStore<T>::Test() > > { > > } > > And I get the same error, unresolved external symbol. > Compiles with my compiler, but I use g++. The only explanation I can > think of, is that the compiler can't see the definition of > CKineStore<T>::Test(). The definition is, of course, included together > with the CKineStore class declaration? Then again, it's five in the > morning here, so I'm beginning to feel tired. If the definition wasn't included you would have a link error. This is not compiler dependent issue. BTW some compilers like Cameau (and Intel?) support exported templates. The export keyword is part of the standard, but neither g++ nor vc++ support it.