mutiple Inhertace from a template class

I want to have a general storage class that can store variety of objects, I don't want to use a heterogeneous container class that stores all of them. I thought of creating a templated storage class, and create a general storage class that inherits from this metaclasses with different types:

template<typename Type>
struct SingleInterface
{
public:
    SingleInterface() = default;
    virtual ~SingleInterface() = default;
    SingleInterface(const SingleInterface &) = default;
    SingleInterface & operator=(const SingleInterface &) = default;
    SingleInterface(SingleInterface &&) = default;
    SingleInterface & operator=(SingleInterface &&) = default;

    void get(const std::string & keyword, Type * ptr)
    {
        // implementation
    }

};

My general class as below:

class MutliInterface: public SingleInterface<double>, SingleInterface<int>
{
public:
    MutliInterface() = default;
    virtual ~MutliInterface() = default;
};

when I create a MutliInterface class, I get the following error:

MutliInterface interface;
double *v;
interface.get("test", v);

'get' is ambiguous '