c++c++11templatestypesafe

c++11 how to convert legacy class to template


I have a legacy class like:

class Wrapper{
public:
    Wrapper(void*);
    void* get();
};

I want to create a type safe wrapper like:

template<class T>
class Wrapper{
public:
    Wrapper(T);
    T get();
};

Stuff like this won't work because of C++11:

template<class T = void*> //Here I would need <>
class Wrapper...

typedef Wrapper<void*> Wrapper; //This isn't allowed

Is there a way to convert Wrapper to a template class without editing all places where it's already used?


Solution

  • If you do not want to change at other places, you can give your templated class a different name (because you don't even use it then in the first place):

    template<typename T>
    class WrapperT
    {
    public:
        WrapperT(T t) : _T(t) {}
        T get() { return _T; }
    private:
        T _T;
    };
    
    using Wrapper = WrapperT<void*>;
    

    If you then removed every usage of Wrapper you can rename WrapperT