Pass 2D array by reference?

[qwepoi123]

How do you pass 2D arrays by reference??

[Cubbi]

Like any other array: type (&name)[size1][size2]

#include <iostream>

template<typename T, std::size_t N, std::size_t M>
void increment_2D(T (&a)[N][M])
{
    for(std::size_t n = 0; n < N; ++n)
        for(std::size_t m = 0; m < M; ++m)
            ++a[n][m];
}

int main()
{
    int a[3][3] = {1,2,3,4,5,6,7,8,9};
    increment_2D(a);
    for(auto& r: a) {
        for(int n: r)
           std::cout << n << ' ';
        std::cout << '\n';
    }
}

online demo: http://ideone.com/NbWYQO

[ajh32]

You could achieve your objective by passing through as a pointer. Remember that a multi-dimensional array is just a contiguous area of memory, so just interate through it:

#include <iostream>

using namespace std;

void print(int* matrix[], const int& rows, const int& cols)
{
	for (int n = 0; n < rows*cols; ++n)
	{
		cout << (*matrix)[n] << endl;
	}
}

int main()
{
	const int ROWS(2), COLS(5);
	int m[ROWS][COLS] = {{1,2,3,4,5},
			     {10,20,30,40,50}};
	int* pMatrix[ROWS];
	*pMatrix = m[0];

	print(pMatrix, ROWS, COLS);

	return 0;
}