在两个相同类的指针之间进行转换的安全性?

Let's say I have two different classes, both represent 2D coordinate data in the same internal way like the following:

class LibA_Vertex{
    public:
    // ... constructors and various methods, operator overloads
    float x, y
};

class LibB_Vertex{
    public:
    // ... same usage and internal data as LibA, but with different methods
    float x, y
};


void foobar(){
    LibA_Vertex * verticesA = new LibA_Vertex[1000];
    verticesA[50].y = 9;
    LibB_Vertex * verticesB = reinterpret_cast<LibB_Vertex*>( vertexA );
    print(verticesB[50].y); // should output a "9"
};

鉴于这两个类和上面的函数是相同的，我能否可靠地指望这种指针转换在每种情况下都能按预期工作?