const_cast in template. Is there a unconst modifier?

Question

I have a template class like this:

template<T>
class MyClass
{
  T* data;
}

Sometimes, I want to use the class with a constant type T as follows:

MyClass<const MyObject> mci;

but I want to modify the data using const_cast<MyObject*>data (it is not important why but MyClass is a reference count smart pointer class which keeps the reference count in the data itself. MyObject is derived from some type which contains the count. The data should not be modified but the count must be modified by the smart pointer.).

Is there a way to remove const-ness from T? Fictional code:

const_cast<unconst T>(data) 

?

Answer 1

The simplest way here would be to make the reference count mutable.

However, if you are interested in how it would work with the const_cast, then reimplementing boost's remove_const should be quite simple:

template <class T>
struct RemoveConst
{
    typedef T type;
};

template <class T>
struct RemoveConst<const T>
{
    typedef T type;
};

const_cast<typename RemoveConst<T>::type*>(t)->inc();