Simpler way to set multiple array slots to one value

Question

I\'m coding in C++, and I have the following code:

int array[30];
array[9] = 1;
array[5] = 1;
array[14] = 1;

array[8] = 2;
array[15] = 2;
array[23] = 2;
array[1         


        

Answer 1

I just had a play around for the sake of fun / experimentation (Note my concerns at the bottom of the answer):

It's used like this:

smartAssign(array)[0][8]       = 1;
smartAssign(array)[1][4][2]    = 2;
smartAssign(array)[3]          = 3;
smartAssign(array)[5][9][6][7] = 4;

Source code:

#include  //Needed to test variables
#include 
#include 

template 
class SmartAssign
{
    ArrayPtr m_array;

public:
    class Proxy
    {
        ArrayPtr m_array;
        size_t m_index;
        Proxy* m_prev;

        Proxy(ArrayPtr array, size_t index)
            : m_array(array)
            , m_index(index)
            , m_prev(nullptr)
        { }

        Proxy(Proxy* prev, size_t index)
            : m_array(prev->m_array)
            , m_index(index)
            , m_prev(prev)
        { }

        void assign(Value value)
        {
            m_array[m_index] = value;            
            for (auto prev = m_prev; prev; prev = prev->m_prev) {
                m_array[prev->m_index] = value;
            }
        }

    public:
        void operator=(Value value)
        {
            assign(value);
        }

        Proxy operator[](size_t index)
        {
          return Proxy{this, index};
        }

        friend class SmartAssign;
    };

    SmartAssign(ArrayPtr array)
        : m_array(array)
    {
    }


    Proxy operator[](size_t index)
    {
        return Proxy{m_array, index};
    }
};

template 
SmartAssign smartAssign(T* array)
{
    return SmartAssign(array);
}

int main()
{
    int array[10];

    smartAssign(array)[0][8]       = 1;
    smartAssign(array)[1][4][2]    = 2;
    smartAssign(array)[3]          = 3;
    smartAssign(array)[5][9][6][7] = 4;

    for (auto i : array) {
        std::cout << i << "\n";
    }

    //Now to test the variables
    assert(array[0] == 1 && array[8] == 1);
    assert(array[1] == 2 && array[4] == 2 && array[2] == 2);
    assert(array[3] == 3);
    assert(array[5] == 4 && array[9] == 4 && array[6] == 4 && array[7] == 4);
}

Let me know what you think, I don't typically write much code like this, I'm sure someone will point out some problems somewhere ;)

I'm not a 100% certain of the lifetime of the proxy objects.