在嵌套模板专门化期间初始化嵌套模板化类的静态成员？

Question

这是我的问题:

template<typename T>
class Outer 
{
public:
    template<typename U>
    class Inner 
    {
    private:
        static int count;
    };

    static int code;
    void print() const
    {
        std::cout << "generic";
    }
};

template<>
template<>
class Outer<bool>::Inner<bool> 
{
    static int count;
};

template<>
template<>
int Outer<bool>::Inner<bool>::count = 4; // ERROR

如何正确初始化？

Answer 1

完全专业化的模板实际上不再是模板,因此您的定义应该只是:

int Outer<bool>::Inner<bool>::count = 4;

完整的,所有定义到位后,您的代码应如下所示:

template<typename T>
class Outer 
{
public:
    template<typename U>
    class Inner 
    {
    private:
        static int count;
    };

    static int code;
    void print() const
    {
        std::cout << "generic";
    }
};

template<typename T>
int Outer<T>::code = 0;

template<typename T>
template<typename U>
int Outer<T>::Inner<U>::count = 0;

template<>
template<>
class Outer<bool>::Inner<bool> 
{
    static int count;
};

int Outer<bool>::Inner<bool>::count = 4;