I was wondering how I can return a 2d array in my function. My code is something like this:
int[][] function ()
{
int chessBoard[x][x];
memset(chessBoard,0,x*x*sizeof(int));
return chessBoard;
}
I get the error message: "error: unexpected unqualified-id before '[' token" on my first line. Any tips on how I can get my function to work properly?
Use vector of vector instead:
template<typename T, size_t N>
std::vector<std::vector<T> > func()
{
std::vector<std::vector<T>> data(N, std::vector<T>(N));
return data;
}
int main ( int argc, char ** argv)
{
std::vector<std::vector<int> > f = func<int, 10>();
return 0;
}
If you are using C++11, you could try with std::array:
template<typename T, size_t N>
std::array<std::array<T, N>, N> func()
{
return std::array<std::array<T, N>, N>();
}
int main ( int argc, char ** argv)
{
auto f = func<int, 10>();
return 0;
}
Unfortunately, arrays cannot be returned from functions. It is clearly stated in the Standard.
C++11 Standard § 8.3.5 Functions
Functions shall not have a return type of type array or function, although they may have a return type of type pointer or reference to such things.
But modern C++ practices advise that you use STL containers to facilitate the confusing syntax and memory allocation. In your particular setup, we can replace your C-style arrays with a std::vector:
std::vector< std::vector<int> > function()
{
return std::vector< std::vector<int> >(x, std::vector<int>(x));
}
int**wouldn't work here with no other changes because it is not layout compatible with a 2D array.