我正在学习 C++，并且在构建我的项目时遇到了链接错误。
该错误与我的代码有关，该代码使输出 << 运算符重载。
这是我得到的错误：
1>lab4.obj : error LNK2019: unresolved external symbol "class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,class Matrix<2,2> const &)" (??6@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@std@@AAV01@ABV?$Matrix@$01$01@@@Z) referenced in function _main
1>c:\users\matt\documents\visual studio 2010\Projects\lab4\Debug\lab4.exe : fatal error LNK1120: 1 unresolved externals
如何修复此错误？我在下面附上了我的代码
#include <iostream>
#include <string>
#include <stdio.h>
using namespace std;
template <int m, int n>
class Matrix{
public:
int data[m][n];
public:
Matrix(){};
void setup(){
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
data[i][j] = 0;
}
}
}
void setAll(int integer){
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
data[i][j] = integer;
}
}
}
void output(){
for(int i=0;i<m;i++){
cout << "[ ";
for(int j=0;j<n;j++){
cout << data[i][j] << " ";
}
cout<<"]"<<endl;
}
}
Matrix<m,n> operator+ (const Matrix<m,n> &rhs)
{
Matrix<m,n> result;
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
result.data[i][j] = this->data[i][j] + rhs.data[i][j];
}
}
return result;
}
Matrix<m,n> operator- (const Matrix<m,n> &rhs)
{
Matrix<m,n> result;
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
result.data[i][j] = this->data[i][j] - rhs.data[i][j];
}
}
return result;
}
template <int l>
Matrix <m,l> operator*(const Matrix<n,l> &rhs) //const
{
//only if number of columns in the first matrix equals the number of rows in the second matrix.
Matrix<m,l> result;
for(int i = 0; i < m; i++){
for(int j = 0 ; j < l ; j++){
result.data[i][j] = 0;
for(int k = 0; k < n; k++){
result.data[i][j] += this->data[i][k] * rhs.data[k][j];
}
}
}
return result;
};
Matrix <m,n> operator*(int scalar){
Matrix <m,n> result;
for(int i= 0; i < m; i++){
for(int j = 0; j < n; j++){
result.data[i][j] = this->data[i][j] * scalar;
}
}
return result;
};
friend ostream& operator<<(ostream &os, const Matrix<m,n> &rhs);
friend Matrix <m,n> operator++(const Matrix<m,n> &rhs, int);
friend Matrix <m,n> operator--(const Matrix<m,n> &rhs, int);
};
template <int m, int n>
ostream& operator<< (ostream &os, const Matrix<m,n> &rhs){
for(int i=0;i<m;i++){
os << "[ ";
for(int j=0;j<n;j++){
os << rhs.data[i][j] << " ";
}
os<<"]"<<endl;
}
return os;
}
template <int m, int n>
Matrix <m,n> operator++(const Matrix<m,n> &rhs, int){
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
rhs.data[i][j]++;
}
}
}
template <int m, int n>
Matrix <m,n> operator--(const Matrix<m,n> &rhs, int){
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
rhs.data[i][j]--;
}
}
}
int main(){
Matrix<2,2> m = Matrix<2,2>();
m.setup();
//m.output();
Matrix<2,2> p = Matrix<2,2>();
p.setup();
Matrix<2,2> z = Matrix<2,2>();
z = m + p;
//z.output();
z = z * z;
cout << z;
string stopper;
getline(cin, stopper);
}