comma_matrix.cc

comma_matrix.cc

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

#define print(x) do {cout << x << endl;} while(0)
#define input(x) do {cin >> x;} while(0)

template<typename T, int sy, int sx>
class Matrix {
public:
    Matrix(): y(sy), x(sx)
    {
        vec.reserve(x * y);
    };
    friend ostream& operator<< (ostream& os, Matrix& mat)
    {
        for (int i = 0; i < mat.y; i++) {
            for (int j = 0; j < mat.x; j++) {
                os << mat.vec[i * mat.x + j] << ' ';
            }
            os << '\n';
        }
        return os;
    }
    friend Matrix<T, sx, sy>& operator<< (Matrix& mat, const T& it)
    {
        mat.ptr = 0;
        mat.vec[mat.ptr++] = it;
        return mat;
    }
    
    friend Matrix<T, sx, sy>& operator, (Matrix& mat, const T& it)
    {
        if (mat.ptr >= mat.x * mat.y) {
            print("ERROR!");
        }
        mat.vec[mat.ptr++] = it;
        return mat;
    }
private:
    int y, x;
    int ptr;
    vector<T> vec;
};

int main()
{
    Matrix<int, 3, 3> mat;
    mat << 1, 2, 3,
           4, 5, 6,
           7, 8, 9;
    print(mat);
    return 0;
}

// ANOTHER TRY

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

#define print(x) do {cout << x << endl;} while(0)
#define input(x) do {cin >> x;} while(0)

template<typename T, int sy, int sx>
class Matrix;

template<typename M, typename T>
struct CommaInitializer;

template<typename T, int sy, int sx>
class Matrix {
public:
    Matrix(): y(sy), x(sx)
    {
        vec.reserve(x * y);
    };
    friend ostream& operator<< (ostream& os, Matrix& mat)
    {
        for (int i = 0; i < mat.y; i++) {
            for (int j = 0; j < mat.x; j++) {
                os << mat.vec[i * mat.x + j] << ' ';
            }
            os << '\n';
        }
        return os;
    }
    friend CommaInitializer<Matrix<T, sy, sx>, T> operator<< (Matrix& mat, const T& it)
    {
        CommaInitializer<Matrix<T, sy, sx>, T> ci(mat);
        ci.append(it);
        return ci;
    }
    friend class CommaInitializer<Matrix<T, sy, sx>, T>;
private:
    int y, x;
    int ptr;
    vector<T> vec;
};

template<typename M, typename T>
struct CommaInitializer {
    CommaInitializer(M& i_mat): mat(i_mat), ptr(0)
    {
        // pass
    }
    M& mat;
    mutable int ptr;
    
    int append(const T& it) const
    {
        if (ptr >= mat.x * mat.y) {
            print("ERROR");
            return -1;
        } else {
            mat.vec[ptr++] = it;
        }
        return 0;
    }
    friend const CommaInitializer<M, T>& operator, (const CommaInitializer<M, T> &ci, const T& it)
    {
        ci.append(it);
        return ci;
    }
};

int main()
{
    Matrix<int, 3, 3> mat;
    mat << 1 , 2 , 3 , 
           4 , 5 , 6 ,
           7 , 8 , 9;
    print(mat);
    return 0;
}