C / C++ / MFC

// This generates error C2146
typedef classB<classA<char>> classB_type;

// This compiles with out error
typedef classA<char> classA_type;
typedef classB<classA_type> classB_type;

// definition of classA
#define _CLASS_A_ classA<T>

template<class T>
class classA
{
    int n_;
public:
    void testFuncA(void);
};

template<class T>
void _CLASS_A_::testFuncA(void){ n_ = 0; }

#undef _CLASS_A_

// definition of classB
#define _CLASS_B_ classB<T>

template<class T>
class classB
{
public:
    typedef T argClass;
    T mT_;
    void testFuncB(void);
};

template<class T>
void classB<T>::testFuncB(){ mT_.testFuncA(); }

#undef _CLASS_B_

// global typedefs
typedef classA<char> classA_type;
typedef classB<classA_type> classB_type;

// main function
int main(int argc, char* argv[])
{
    classB_type B;
    B.testFuncB();
    return 0;
}