Ошибка c2676 c

I’m trying to write code in C++ (using template) to add between 2 matrices.

I have the following code in .h file.

#ifndef __MATRIX_H__
#define __MATRIX_H__

//***************************
//         matrix
//***************************

template <class T, int rows, int cols> class matrix {
public:
    T mat[rows][cols];
    matrix();
    matrix(T _mat[rows][cols]);
    matrix operator+(const matrix& b);
};

template <class T, int rows, int cols> matrix <T,rows,cols> :: matrix (T _mat[rows][cols]){
    for (int i=0; i<rows; i++){
        for (int j=0; j<cols; j++){
            mat[i][j] = _mat[i][j];
        }
    }
}

template <class T, int rows, int cols> matrix <T,rows,cols> :: matrix (){
    for (int i=0; i<rows; i++){
        for (int j=0; j<cols; j++){
            mat[i][j] = 0;
        }
    }
}

template <class T, int rows, int cols> matrix <T,rows,cols> matrix <T,rows,cols>::operator+(const matrix<T, rows, cols>& b){
    matrix<T, rows, cols> tmp;
    for (int i=0; i<rows; i++){
        for (int j=0; j<cols; j++){
            tmp[i][j] = this->mat[i][j] + b.mat[i][j];
        }
    }
    return tmp;
}



#endif

my .cpp :

#include "tar5_matrix.h"
int main(){

    int mat1[2][2] = {1,2,3,4};
    int mat2[2][2] = {5,6,7,8};
    matrix<int, 2, 2> C;
    matrix<int, 2, 2> A = mat1;
    matrix<int, 2, 2> B = mat2;
    C = A+B;
    return 0;
}

When compiling, I get the following error:

1>c:\users\karin\desktop\lior\study\cpp\cpp_project\cpp_project\tar5_matrix.h(36):
error C2676: binary ‘[‘ : ‘matrix’ does not define this
operator or a conversion to a type acceptable to the predefined
operator

Please advise

I have a custom List class and I want to write a method to sort items in this List. For example:

void ListAlgoritms<T>::Sort(List<T>& list)
{
    T temp;

    for (int i = 0; i < list.GetSize() - 1; i++)
    {
        if (list[i] > list[i + 1])
        {
            list.Swap(i, i + 1);
        }

        i--;
    }
}

Overloading of square brackets in List:

template<typename T>
const T & List<T>::operator[](int index)
{
    if (index < this->_size || index >= this->_size)
    {
        throw new std::exception("Out of array border");
    }

    ListNode<T> *cur = this->_head;
    int counter = 0;

    while (cur != nullptr)
    {
        if (counter == index)
        {
            return cur->data;
        }

        cur = cur->next;
        counter++;
    }

    return NULL;
}

To comapre two objects in Sort method I overload ‘>’ and ‘<‘ in the classes that I want to add to the List. For example:

bool Coach::operator >(const Coach & obj) const
{
    return strlen(this->_vehicleInfo._vechicleName) > strlen(obj._vehicleInfo._vechicleName);
}

bool Coach::operator <(const Coach & obj) const
{
    return strlen(this->_vehicleInfo._vechicleName) < strlen(obj._vehicleInfo._vechicleName);
}

But when I try to compile the project, I have this error:

C2676. Binary '>': 'const T' does not define this operator or a conversion to a type acceptable to the predefined operator.

But it’s works good with overloading >> and << operators (input/output operators)

   class Coach : public PassengerVehicle
{
public:
    Coach(double fuelConsumption = 0, int maxNumberOfPersons = 0, double ticketCost = 0, const char* name = new char[10]{ "undefine" }, int countOfSections = 0);
    ~Coach();

    Coach(const Coach &coach);

public:
    void Move(double) override;
    double GetProfit() override;
    int GetCountOfSections();
    void SetCountOfSections(int count); 

    void SetHeader();
    void SetData(texttable::TextTable& t);
    Coach& operator = (Coach& obj);
    bool operator > (const Coach& obj) const;
    bool operator < (const Coach& obj) const;
    friend std::ostream & operator << (std::ostream &out, Coach& vehicle);
    friend std::istream & operator >> (std::istream &in, Coach& vehicle);

private:
    int CountOfSections;

};

/////////////////////////////

       T inputData;
    ...
std::cin >> inputData;

I’m trying to write code in C++ (using template) to add between 2 matrices.

I have the following code in .h file.

#ifndef __MATRIX_H__
#define __MATRIX_H__

//***************************
//         matrix
//***************************

template <class T, int rows, int cols> class matrix {
public:
    T mat[rows][cols];
    matrix();
    matrix(T _mat[rows][cols]);
    matrix operator+(const matrix& b);
};

template <class T, int rows, int cols> matrix <T,rows,cols> :: matrix (T _mat[rows][cols]){
    for (int i=0; i<rows; i++){
        for (int j=0; j<cols; j++){
            mat[i][j] = _mat[i][j];
        }
    }
}

template <class T, int rows, int cols> matrix <T,rows,cols> :: matrix (){
    for (int i=0; i<rows; i++){
        for (int j=0; j<cols; j++){
            mat[i][j] = 0;
        }
    }
}

template <class T, int rows, int cols> matrix <T,rows,cols> matrix <T,rows,cols>::operator+(const matrix<T, rows, cols>& b){
    matrix<T, rows, cols> tmp;
    for (int i=0; i<rows; i++){
        for (int j=0; j<cols; j++){
            tmp[i][j] = this->mat[i][j] + b.mat[i][j];
        }
    }
    return tmp;
}



#endif

my .cpp :

#include "tar5_matrix.h"
int main(){

    int mat1[2][2] = {1,2,3,4};
    int mat2[2][2] = {5,6,7,8};
    matrix<int, 2, 2> C;
    matrix<int, 2, 2> A = mat1;
    matrix<int, 2, 2> B = mat2;
    C = A+B;
    return 0;
}

When compiling, I get the following error:

1>c:\users\karin\desktop\lior\study\cpp\cpp_project\cpp_project\tar5_matrix.h(36):
error C2676: binary ‘[‘ : ‘matrix’ does not define this
operator or a conversion to a type acceptable to the predefined
operator

Please advise