Enumeration of struct elements c++

Question

I'm simply trying to create an enumeration of several struct elements with C++ (actually it may look more like C, so if you have any suggestion to make it look more like C++, I'll take it). Here is the code :

struct Vect
{
    int x;
    int y;
};

enum Direction
{
    right = (Vect) {1, 0},
    left = (Vect) {-1, 0},
    down = (Vect) {0, 1},
    up = (Vect) {0, -1}
};

The error I get from g++ is : "enumerator value for ‘right’ is not an integer constant" (and so for the others). Is it even possible to do this ? Otherwise I can find another way to do it, but I found this solution quite elegant.

Answer 1

If all you want is a bunch of constant expressions of type Vect, you can define them as follows:

namespace Direction
{
    constexpr Vect right = { 1,  0 };
    constexpr Vect left  = {-1,  0 };
    constexpr Vect down  = { 0,  1 };
    constexpr Vect up    = { 0, -1 };
}

Vect as you showed it is a literal type, which is what makes it a possibility. Pretty much why constexpr was introduced.