Question

I am wondering if there is a way to overload operator[] for a non-class type in C++.

Basically, there is a data type which is a pointer (CFDictionaryRef from CoreFoundation). But it’s not a class (i know that overloading operator[] for a specific class is allowed). I know how to access each element inside the CFDictionaryRef (for example, by using CFDictionaryGetIndex(CFIndex index); ). I want to make it simplified so that I don’t have to write that function call every time. I want to overload the operator[ ] for CFDictionaryRef. But since it’s not a class, from what I see, it’s not possible.

Anyone got any suggestions?

Answer 1

You’re right, it’s not possible to overload operators on non-user-defined types.

What you might do is wrap the pointer in a class and overload the operators on the class itself. Since you can only overload operators on class types, this is the only option.

class CFDictionaryRefWrapper {
public:
    CFDictionaryRefWrapper(CFDictionaryRef r) : dref(r) { }

    CFDictionaryRef dref;

    Type operator[](unsigned int index) {
        /* do whatever with dref */
    }
};

This also has the advantage of being able to automatically manage the lifetime of the pointer (RAII) if you need to do that.