将静态常量数据成员初始化移到类定义之外

Question

I read that defining or initializing a static member inside the class definition would violate the idea that a class definition is only a blueprint and does not set aside any memory.

But I have a constant value that I need to initialize the array inside the class, so I had to initialize it inside the class definition, and it works fine, but, is there a better method to do it? or this is the best method?

class A{
    static const int N = 32;
    int arr[N];
};

Answer 1

I read that defining or initializing a static member inside the class definition would violate the idea that a class definition is only a blueprint and does not set aside any memory

My humble opinion: unread that thing.

In-class initializer is a good thing. Of course there are situations where is not the best solution, but in your case it's not only the best solution, it's pretty much the only solution as the size of the array must be known at compile time (except making N a template argument).

As a side note, I would suggest you strongly consider moving away from C arrays to std::array :

class A {
    static constexpr int N = 32;
    std::array<int, N> arr;
};