相关疑难解决方法(0)

为什么以下代码会出现以下错误？

为什么类型需要完整才能投入void？

struct Incomplete;
class Class
{
    virtual void foo(Incomplete &incomplete)
    {
        (void) incomplete;
        throw std::logic_error("not implemented");
    }
};

错误:

error C2027: use of undefined type 'Incomplete'  
    see declaration of 'Incomplete'