class static property wrong initiation in qt applications

//代码占位符
class FA{
public:
    static QVector<FA*> allFA;
    static int Register(FA* p);
};
QVector<FA*> FA::allFA = QVector<FA*>();
int FA::Register(FA* p){
    allFA.push_back(p);
    return 1;
}class CA:public FA{
public:
    static CA* pC;
    static int result;
    static CA* getInstance();
};

CA* CA::pC = nullptr;
int CA::result = Register(getInstance());
CA* CA::getInstance(){
    if (!pC)
        pC = new CA;
    return pC;
}

class CB:public FA{
public:
    static CB* pC;
    static int result;
    static CB* getInstance();
};

CB* CB::pC = nullptr;
int CB::result = Register(getInstance());
CB* CB::getInstance(){
    if (!pC)
        pC = new CB;
    return pC;
}