Can't initialize an object in a member initialization list

CCalcArchive::CCalcArchive() : m_calcMap()
{
}

typedef CTypedPtrMap<CMapStringToPtr, CString, CCalculation*> CCalcMap;
CCalcMap& m_calcMap;

error C2440: 'initializing' : cannot convert from 'int' to 'CCalcArchive::CCalcMap &'

mfctest.cpp(72) : warning C4413: '' : reference member is initialized to a temporary
                                       that doesn't persist after the constructor exits