C ++与部分模板专业化语法混淆

Question

Is there a way I could avoid using Range2 as a name and have both classes named Range ? I'm a bit confused with the C++ template syntax.

template <int BEGIN, int END>
class Range2
{
public:
    class Iterator
    {
    private:
        int n;

    public:
        Iterator(int n)
            : n(n)
        {
        }

        int operator *() const
        {
            return n;
        }

        Iterator const & operator ++()
        {
            ++n;
            return *this;
        }

        bool operator !=(Iterator const & i) const
        {
            return n != i.n;
        }
    };

    Iterator begin() const
    {
        return Iterator(BEGIN);
    }

    Iterator end() const
    {
        return Iterator(END);
    }
};

template<int END>
class Range
    : public Range2<0, END>
{
};

Answer 1

As with function arguments, in C++ template arguments can have a default value. The only thing you will have to pay for this putting the END, which has no default value, before the BEGIN, which has 0 as default.

// Here we add the default parameter to BEGIN
// The arguments are switched because END is without a default       
// parameter, so it has to come before BEGIN that has one
template <int END, int BEGIN=0>
// The class itself is the same, but now you can use it
// without giving a BEGIN parameters
class Range
{
public:
    class Iterator
    {
    private:
        int n;

    public:
        Iterator(int n)
            : n(n)
        {
        }

        int operator *() const
        {
            return n;
        }

        Iterator const & operator ++()
        {
            ++n;
            return *this;
        }

        bool operator !=(Iterator const & i) const
        {
            return n != i.n;
        }
    };

    Iterator begin() const
    {
        return Iterator(BEGIN);
    }

    Iterator end() const
    {
        return Iterator(END);
    }
};

It compiles and should work as intended. Without a main, I wasn't able to test it, though.

EDIT: I added some comments and here an example of usage, just for clarity:

Range<10, 3> r(3); /*here we use it as usual, pay attention begin is 
                     now the second argument and not the first */
Range<10> r(0);    /* here we don't give a BEGIN argument, the 
                      compiler will use the default one */