Template specialization with a specific templated class - c++

Question

Given the following simple C++ class:
using namespace std;
template<class T1>
class ValueWrapper {
private:
T1 value_;
public:
ValueWrapper() {}
ValueWrapper(const T1& value) {
value_ = value;
}
ValueWrapper(const ValueWrapper<T1> &wrapper) {
value_ = wrapper.value_;
}
ValueWrapper& Set(const T1& value) {
value_ = value;
return *this;
}
T1 Get() const {
return value_;
}
};
I was trying to create a simple shared_ptr wrapper for that class (ultimately allowing the developer to use the class without the dereferencing operator if desired). While I've seen a few examples of wrapping a shared_ptr, I couldn't find any that also used a specialization for a templated class.
Using the class above, I created a ValueShared class which derives from shared_ptr:
template<class T1>
class ValueShared : public shared_ptr<T1> {
public:
ValueShared& operator =(const T1& rhs) {
// nothing to do in base
return *this;
}
};
Then, I created a custom make_shared_value function:
//
// TEMPLATE FUNCTION make_shared
template<class T1, class... Types> inline
ValueShared<T1> make_shared_value(Types&&... Arguments)
{ // make a shared_ptr
_Ref_count_obj<T1> *_Rx = new _Ref_count_obj<T1>(_STD forward<Types>(Arguments)...);
ValueShared<T1> _Ret;
_Ret._Resetp0(_Rx->_Getptr(), _Rx);
return (_Ret);
}
But, here's the problem code:
template<class T1, class ValueWrapper<T1>>
class ValueShared<ValueWrapper<T1>> : public shared_ptr<ValueWrapper<T1>>{
public:
ValueShared& operator =(const ValueWrapper<T1>& rhs) {
auto self = this->get();
self.Set(rhs->Get());
return *this;
}
};
I wanted to provide a specialization of the equals operator here that was specialized to the ValueWrapper class (so that it would Get/Set the value from the right hand side value).
I've tried a few things, but the current error is:
error C2943: 'ValueWrapper<T1>' : template-class-id redefined
as a type argument of a template
Maybe this isn't the proper approach, or maybe it's not possible?

Answer 1

Following should remove your error:
template<class T1>
class ValueShared<ValueWrapper<T1>> : public shared_ptr<ValueWrapper<T1>> {
public:
ValueShared& operator =(const ValueWrapper<T1>& rhs)
{
auto self = this->get();
self->Set(rhs.Get());
return *this;
}
};