Dynamic allocated 2d array in c++ : I have in my Class 2 const int variables:

const int m_width;
const int m_height;

In my constructor I have set the variables and I want to create a 2D array with exactly this size that will be passed by value from the player. I am trying to make a TicTacToe game. I need the input of the user to determine the size of the playing field(in this case the width and height of it). How do I dynamically declare a 2D array in my situation?

Thank you in advance.