BUG: instantiating templates with typedef ('operator...' functions)

[Nick]

// 
// This example shows the problem of instantiating the 'operator=='
function
// using a typedef. Any other function beside that operator instantiates 
// correctly.
//
//
// To see the problem, compile as 
//
//      g++ -c test.C -DSHOW
//
// To see how other functions are doing fine, compile as
//
//      g++ -c test.C 
//___________________________________________________________________________
//
// WORKAROUND:
//
// The solution for this is not to use the typedef, but the original
class.
// In this particular example, omu_PrimIntDictionary will not work, but
// the omu_PrimDictionary<int> will. Note that omu_PrimIntDictionary is
// just a typedef of omu_PrimDictionary<int>. 
//___________________________________________________________________________
//
// Submitter: Nick Monyatovsky <mon@hks.com> or <m@loa.com>
//      Date: 2000/07/15
//   Version: gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2
release)
//    System: Linux 2.2.14-5.0 (RedHat 6.1 on Intel Pentium III)
//___________________________________________________________________________

#if defined(SHOW)
#   define PROBLEM_FUNCTION operator==
#else
#   define PROBLEM_FUNCTION prettyPrint
#endif


#include <iostream.h>

class omu_Primitive {
public:
    virtual bool PROBLEM_FUNCTION(const omu_Primitive &) const;
protected:
    int type;
};

template <class T>
class omu_PrimDictionary : public omu_Primitive
{
public:
    virtual bool PROBLEM_FUNCTION(const omu_Primitive& arg) const;
};



template <class T>
bool omu_PrimDictionary<T>::PROBLEM_FUNCTION(const omu_Primitive& arg)
const 
{
    if (type > 0) 
	return true;
    else
    	return false;
}

//////////////////////////// PROBLEM HERE /////////////////////////////
//
// operator== function does not want to instantiate itself correctly.
//            Any other function in its place instantiates itself 
//            as omu_PrimDictionary<int>..., but not the operator==.
//            
// SOLUTION:  Do not use the typedef. Use the underlying type directly.
//
///////////////////////////////////////////////////////////////////////

typedef omu_PrimDictionary<int> omu_PrimIntDictionary;

template <> 
//bool omu_PrimDictionary<int>::PROBLEM_FUNCTION(const omu_Primitive&
arg) const 
bool omu_PrimIntDictionary::PROBLEM_FUNCTION(const omu_Primitive& arg)
const 
{
  if (type > 0) 
     return true;
  else
     return false;
}