Inquiry about class variable declarations in C++

Question

I have a class to represent a 3D vector of floats:

class Vector3D
{
    public:

    float x, y, z;
    float * const data;

    Vector3D() : x(0.0), y(0.0),         


        

Answer 1

Yes. This class is layout-compatible standard-layout, because:

• You have no virtual functions.
• All data members are in a single access specifier block (the public:)

Because of this, it's guaranteed to be laid out sequentially just like a C structure. This is what allows you to read and write file headers as structures.