有两2*3规模的矩阵a和b，编写程序，求两个矩阵之和。重做插入运算符和提取运算符，使之能用于该矩阵的输入和输出。重载运算符“+”，使之能用于矩阵相加，如c=a+b.用完整地准确地c++语言表示

以下是实现上述功能的完整C++代码：

#include <iostream>
using namespace std;

class Matrix {
private:
    int row, col;
    int **data;
public:
    Matrix(int r, int c) : row(r), col(c) {
        data = new int*[row];
        for (int i = 0; i < row; i++) {
            data[i] = new int[col];
        }
    }

    friend istream& operator >> (istream& in, Matrix& m) {
        for (int i = 0; i < m.row; i++) {
            for (int j = 0; j < m.col; j++) {
                in >> m.data[i][j];
            }
        }
        return in;
    }

    friend ostream& operator << (ostream& out, const Matrix& m) {
        for (int i = 0; i < m.row; i++) {
            for (int j = 0; j < m.col; j++) {
                out << m.data[i][j] << " ";
            }
            out << endl;
        }
        return out;
    }

    Matrix operator + (const Matrix& m) const {
        if (row != m.row || col != m.col) {
            cerr << "Error: Matrix size does not match" << endl;
            return Matrix(0, 0);
        }
        Matrix res(row, col);
        for (int i = 0; i < row; i++) {
            for (int j = 0; j < col; j++) {
                res.data[i][j] = data[i][j] + m.data[i][j];
            }
        }
        return res;
    }
};

int main() {
    Matrix a(2, 3), b(2, 3);
    cout << "Input Matrix a:" << endl;
    cin >> a;
    cout << "Input Matrix b:" << endl;
    cin >> b;
    cout << "Matrix a:" << endl << a;
    cout << "Matrix b:" << endl << b;
    Matrix c = a + b;
    cout << "Matrix c = a + b:" << endl << c;
    return 0;
}

程序中定义了一个Matrix类，其中包含了矩阵的行列数和数据。为了方便输入和输出矩阵，重载了插入运算符和提取运算符。重载了加法运算符，使得可以直接使用“+”来计算矩阵的和。在主函数中，首先输入两个矩阵a和b，然后计算它们的和c，最后输出结果。