错误C2955：“ ListRemake”：使用类模板需要模板参数列表

Question

template <class T>
class ListRemake
{
    ...
    friend ostream& operator << (ostream& out, const ListRemake& obj);
};

template <class T>
ostream& operator << (ostream& out, const ListRemake& obj)
{
    for (int i = 0; i < obj.size; i++)
        out << obj[i] << '\n';
    return out;
}

Gives the error C2955: 'ListRemake' : use of class template requires template argument list.

Answer 1

该错误告诉您ListRemake是模板，因此您需要实例化它以将其用作类型（在<<操作符中执行的操作）。

Answer 2

Replace

ostream& operator << (ostream& out, const ListRemake& obj)

with

ostream& operator << (ostream& out, const ListRemake<T>& obj)