C++ 向量hpp:13:33:错误：声明‘；操作员<<’；作为非功能

我有这个错误

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vect.hpp:13:33:错误：声明'operator友元声明指的是

运算符的实例化，您也可以在类内进行定义

#include <iostream>

template<unsigned d>
class Vect{
    protected:
        double * coord;
    public:
        Vect() {for(int i=0, i<d, i++){*(coord+i)=0;}}
        ~Vect(){delete coord; coord=nullptr;}
        Vect(const Vect &);
        double operator=(const Vect &);
        double operator[](unsigned i) const{return *(coord+i);}
        friend std::ostream & operator<<(std::ostream &os, const Vect<d> &obj)
        {
          // Your code goes here
        }

};

#包括
模板
类向量{
受保护的：
双*坐标；
公众：
Vect（）{for（int i=0，i
friend std::ostream & operator<< <>(std::ostream &, const Vect<d> &); 

// forward declaration
template<unsigned d>
class Vect;

// primary template declaration of operator<<
template<unsigned d>
std::ostream & operator<< (std::ostream &, const Vect<d> &); 

template<unsigned d>
class Vect{
    protected:
        double * coord;
    public:
        Vect() {for(int i=0; i<d; i++){*(coord+i)=0;}}
        ~Vect(){delete coord; coord=nullptr;}
        Vect(const Vect &);
        double operator=(const Vect &);
        double operator[](unsigned i) const{return *(coord+i);}
        friend std::ostream & operator<< <>(std::ostream &, const Vect<d> &); 
};

#include <iostream>

template<unsigned d>
class Vect{
    protected:
        double * coord;
    public:
        Vect() {for(int i=0, i<d, i++){*(coord+i)=0;}}
        ~Vect(){delete coord; coord=nullptr;}
        Vect(const Vect &);
        double operator=(const Vect &);
        double operator[](unsigned i) const{return *(coord+i);}
        friend std::ostream & operator<<(std::ostream &os, const Vect<d> &obj)
        {
          // Your code goes here
        }

};