c++ templates: problem with member specialization
- by ChAoS
I am attempting to create a template "AutoClass" that create an arbitrary class with an arbitrary set of members, such as:
AutoClass<int,int,double,double> a;
a.set(1,1);
a.set(0,2);
a.set(3,99.7);
std::cout << "Hello world! " << a.get(0) << " " << a.get(1) << " " << a.get(3) << std::endl;
By now I have an AutoClass with a working "set" member:
class nothing {};
template < typename T1 = nothing, typename T2 = nothing, typename T3 = nothing,
typename T4 = nothing, typename T5 = nothing, typename T6 = nothing>
class AutoClass;
template <>
class AutoClass<nothing, nothing, nothing,
nothing, nothing, nothing>
{
public:
template <typename U> void set(int n,U v){}
};
template < typename T1, typename T2, typename T3,
typename T4, typename T5, typename T6>
class AutoClass: AutoClass<T2,T3,T4,T5,T6>
{
public:
T1 V;
template <typename U> void set(int n,U v)
{
if (n <= 0)
V = v;
else
AutoClass<T2,T3,T4,T5,T6>::set(n-1,v);
}
};
and I started to have problems implementing the corresponding "get". This approach doesn't compile:
template < typename T1, typename T2, typename T3,
typename T4, typename T5, typename T6>
class AutoClass: AutoClass<T2,T3,T4,T5,T6>
{
public:
T1 V;
template <typename U> void set(int n,U v)
{
if (n <= 0)
V = v;
else
AutoClass<T2,T3,T4,T5,T6>::set(n-1,v);
}
template <typename W> W get(int n)
{
if (n <= 0)
return V;
else
return AutoClass<T2,T3,T4,T5,T6>::get(n-1);
}
template <> T1 get(int n)
{
if (n <= 0)
return V;
else
return AutoClass<T2,T3,T4,T5,T6>::get(n-1);
}
};
Besides, it seems I need to implement get for the <nothing, nothing, nothing, nothing, nothing, nothing> specialization. Any Idea on how to solve this?
