如何在C++中使用重载的operator==检查2d点和3d点是否相同？

class Point2D {
public:
    double x, y;

    Point2D(double xVal, double yVal) : x(xVal), y(yVal) {}
};

class Point3D {
public:
    double x, y, z;

    Point3D(double xVal, double yVal, double zVal) : x(xVal), y(yVal), z(zVal) {}
};

bool operator==(const Point2D& lhs, const Point2D& rhs) {
    return lhs.x == rhs.x && lhs.y == rhs.y;
}

bool operator==(const Point3D& lhs, const Point3D& rhs) {
    return lhs.x == rhs.x && lhs.y == rhs.y && lhs.z == rhs.z;
}

Point2D p1(2.0, 3.0);
Point2D p2(2.0, 3.0);

if (p1 == p2) {
    // 两个2D点相同
} else {
    // 两个2D点不相同
}

Point3D p3(2.0, 3.0, 4.0);
Point3D p4(2.0, 3.0, 4.0);

if (p3 == p4) {
    // 两个3D点相同
} else {
    // 两个3D点不相同
}