一个百思不解的模板定义报错问题

[old-six-programmer]

哪位大神帮忙看下，以下定义红色标注部分为什么会报错：

template<class T, class Left, class Right>
class Base
{
public:
    Base(Left* left, Right* right) : left_(left), right_(right) {}

    T* GetDrived() { return static_cast<T*>(this); }

    void Test()
    {
        GetDrived()->DoTest();
    }

private:
    Left* left_;
    Right* right_;
};

template<class Left, class Right>
class DrivedA : public Base<DrivedA, Left, Right> // 此处报错
{
public:
    DrivedA(Left* left, Right* right) : Base<DrivedA, Left, Right>::Base(left, right) {}

    void DoTest()
    {
        std::cout << "DrivedA::DoTest()" << std::endl;
    }
};

错误：

main.cpp:97:49: 错误：实参 1 的类型/值不匹配，在‘template<class T, class Left, class Right> class Base’的模板参数列表中
class DrivedA : public Base<DrivedA, Left, Right>
^
main.cpp:97:49: 错误：需要一个类型，却给出了‘DrivedA’

[FancyMouse]

public base<DerivedA<Left,Right>, Left, Right>

[飞天御剑流]

改为Base<DrivedA< Left, Right >, Left, Right>