c++ assignment operator overloading - c++

Question

Hello everyone i'm trying to write an assignment operator for this class so i can assign an array like thisint[] = {0, 1, 2, 3} to my Tableau class
originally i wanted to do this
Tableau<T>& operator=(T arr[])
{
return Tableau(tab, sizeofarray);
}
because i already wrote a constructor that takes and array and the size as its argument
and i ran into a problem with the size of the the array i don't know how to find it
how can i find the size of the array or is there a better way to do this
template<typename T>
class Tableau
{
public:
Tableau(int s = 0) : size(s), ptr(new T[size])
{
for (int i = 0; i < size; i++)
{
ptr[i] = 0;
}
}
Tableau(T tab[], int s = 0) : size(s), ptr(new T[size])
{
for (int i = 0; i < size; i++)
{
ptr[i] = tab[i];
}
}
~Tableau()
{
delete[] ptr;
}
Tableau<T>& operator=( T tab[])
{
}
T commule()
{
T com = 0;
for (int i = 0; i < size; i++)
{
com += ptr[i];
}
return com;
}
T& operator[](const int index)
{
return ptr[index];
}
private:
int size;
T* ptr;
};
int main()
{
int k[] = { 8, 12, 5, 9, 55};
Tableau<int> TI(k, 2);
TI = k;
return 0;
}

Answer 1

You can use:
template <std::size_t N>
Tableau<T>& operator=(T (&arr)[N])
{
// This is not right.
// The returned value is a temporary.
// return Tableau(arr, N);
// Update the contents of the object.
// ...
// Then, return a reference to this object.
return *this;
}
With that member function template, when you invoke:
int k[] = { 8, 12, 5, 9, 55};
Tableau<int> TI(k, 2);
TI = k;
The operator= function is instantiated with N = 5 and k as the value of arr. Hence, you get the size of the array as well as the contents of the array.
However, it is worth pointing out that if you use:
int k[] = { 8, 12, 5, 9, 55};
int* k2 = k;
Tableau<int> TI(k, 2);
TI = k2;
it won't work. k2 is not an array. It is a pointer to an int, which happens to point to the first element of k.