Base class template instantiation depending on derived class constructor argument type
template <class T>
class foo
{
int a;
public:
    foo(T a){}
    // When I convert the constructor to a function template, it works fine.
    // template <typename T> foo(T a){}
};

class bar : public foo<class T>
{
public:
    bar(int a):foo(a){}
};

int main(void)
{
    bar obj(10);
    system("pause");
    return 0;
}

template<class T>
class bar : public foo<T>
{
public:
    bar(int a):foo(a){}
};


int main()
{
    bar<int> obj(10);
}

class bar : public foo<int>
{
public:
    bar(int a):foo(a){}
};


int main()
{
    bar obj(10);
}