Reloading of indexation

[shizuka]

There's a class:

class A
{
   public:
     int& operator [] (int a)
     {
        return x.at(a);
     }
     int operator [] (int a) const
     {
        return x.at(a);
     }
   private:
     vector<int> x;
};

Since both overloads are the same, I want to combine them into a template. Can we do that?

[amarantha]

No.

Although these two methods contain the same text, they are completely different: one working on a constant object and returning the whole number by producing a constant method at; the other working on a non-constant object, returning the reference from a non-constant method at. In general, they have different signatures and different implementations.

By the way, usually overloads do the following:

int& operator [] (int a)
const int& operator [] (int a) const

Shablons suggest that the class is grouped according to a certain parameter (or weight). There's nothing to do with it. Well, if you want your class to be supportive, not only. intYou can make a template:

template <typename T>
class A
{
   public:
     T& operator [] (int a)
     {
        return x.at(a);
     }
     const T& operator [] (int a) const
     {
        return x.at(a);
     }
   private:
     vector<T> x;
};