A proper way to create a matrix in c++

Question

I want to create an adjacency matrix for a graph. Since I read it is not safe to use arrays of the form matrix[x][y] because they don't check for range, I decided to use the vector template class of the stl. All I need to store in the matrix are boolean values. So my question is, if using std::vector<std::vector<bool>* >* produces too much overhead or if there is a more simple way for a matrix and how I can properly initialize it.

EDIT: Thanks a lot for the quick answers. I just realized, that of course I don't need any pointers. The size of the matrix will be initialized right in the beginning and won't change until the end of the program. It is for a school project, so it would be good if I write "nice" code, although technically performance isn't too important. Using the STL is fine. Using something like boost, is probably not appreciated.

Answer 1

Note that also you can use boost.ublas for matrix creation and manipulation and also boost.graph to represent and manipulate graphs in a number of ways, as well as using algorithms on them, etc.

Edit: Anyway, doing a range-check version of a vector for your purposes is not a hard thing:

template <typename T> class BoundsMatrix {         std::vector<T> inner_;         unsigned int dimx_, dimy_;  public:         BoundsMatrix (unsigned int dimx, unsigned int dimy)                 : dimx_ (dimx), dimy_ (dimy)         {                 inner_.resize (dimx_*dimy_);         }          T& operator()(unsigned int x, unsigned int y)         {                 if (x >= dimx_ || y>= dimy_)                         throw std::out_of_range("matrix indices out of range"); // ouch                 return inner_[dimx_*y + x];         } }; 

Note that you would also need to add the const version of the operators, and/or iterators, and the strange use of exceptions, but you get the idea.