在C++中實現矩陣類的加減乘除，首先需要創建一個矩陣類（Matrix），然后為該類定義加減乘除的運算符重載函數。以下是一個簡單的示例：

#include<iostream>
#include<vector>

class Matrix {
public:
    Matrix(int rows, int cols) : rows_(rows), cols_(cols), data_(rows * cols, 0) {}

    // 獲取矩陣的行數
    int rows() const { return rows_; }

    // 獲取矩陣的列數
    int cols() const { return cols_; }

    // 獲取矩陣中指定位置的元素
    double& operator()(int row, int col) {
        return data_[row * cols_ + col];
    }

    // 獲取矩陣中指定位置的元素（常量版本）
    double operator()(int row, int col) const {
        return data_[row * cols_ + col];
    }

    // 矩陣加法
    Matrix operator+(const Matrix& other) const;

    // 矩陣減法
    Matrix operator-(const Matrix& other) const;

    // 矩陣乘法
    Matrix operator*(const Matrix& other) const;

private:
    int rows_;
    int cols_;
    std::vector<double> data_;
};

// 矩陣加法
Matrix Matrix::operator+(const Matrix& other) const {
    if (rows_ != other.rows() || cols_ != other.cols()) {
        throw std::invalid_argument("Matrix dimensions do not match for addition.");
    }

    Matrix result(rows_, cols_);
    for (int i = 0; i< rows_; ++i) {
        for (int j = 0; j< cols_; ++j) {
            result(i, j) = (*this)(i, j) + other(i, j);
        }
    }
    return result;
}

// 矩陣減法
Matrix Matrix::operator-(const Matrix& other) const {
    if (rows_ != other.rows() || cols_ != other.cols()) {
        throw std::invalid_argument("Matrix dimensions do not match for subtraction.");
    }

    Matrix result(rows_, cols_);
    for (int i = 0; i< rows_; ++i) {
        for (int j = 0; j< cols_; ++j) {
            result(i, j) = (*this)(i, j) - other(i, j);
        }
    }
    return result;
}

// 矩陣乘法
Matrix Matrix::operator*(const Matrix& other) const {
    if (cols_ != other.rows()) {
        throw std::invalid_argument("Matrix dimensions do not match for multiplication.");
    }

    Matrix result(rows_, other.cols());
    for (int i = 0; i< rows_; ++i) {
        for (int j = 0; j< other.cols(); ++j) {
            for (int k = 0; k< cols_; ++k) {
                result(i, j) += (*this)(i, k) * other(k, j);
            }
        }
    }
    return result;
}

int main() {
    // 示例：創建兩個矩陣并進行加減乘除運算
    Matrix A(2, 2);
    Matrix B(2, 2);

    A(0, 0) = 1; A(0, 1) = 2;
    A(1, 0) = 3; A(1, 1) = 4;

    B(0, 0) = 5; B(0, 1) = 6;
    B(1, 0) = 7; B(1, 1) = 8;

    Matrix C = A + B;
    Matrix D = A - B;
    Matrix E = A * B;

    // 輸出結果
    std::cout << "A + B:\n";
    for (int i = 0; i < C.rows(); ++i) {
        for (int j = 0; j < C.cols(); ++j) {
            std::cout << C(i, j) << " ";
        }
        std::cout<< std::endl;
    }

    std::cout << "A - B:\n";
    for (int i = 0; i < D.rows(); ++i) {
        for (int j = 0; j < D.cols(); ++j) {
            std::cout << D(i, j) << " ";
        }
        std::cout<< std::endl;
    }

    std::cout << "A * B:\n";
    for (int i = 0; i < E.rows(); ++i) {
        for (int j = 0; j < E.cols(); ++j) {
            std::cout << E(i, j) << " ";
        }
        std::cout<< std::endl;
    }

    return 0;
}

這個示例中，我們創建了一個名為Matrix的矩陣類，并為其定義了加減乘除的運算符重載函數。在main函數中，我們創建了兩個矩陣并進行了加減乘除運算，最后將結果輸出到控制臺。