How to write move constructor and move assignment operator for dynamic array or uni_ptr?

I have a dynamic array in the class. I have two questions:

1. I am wondering how to write move constructor and move assignment operator for dynamic array Tile* mytiles?
2. How can the array be written as a smart pointer uni_ptr? Here is the code:

class Grid
{
private:
    size_t _rows_;
    size_t _cols_;
    Tile _initialTile_;
    Tile* mytiles;

public:
    // Tile is a self defined class
    Grid(size_t rows, size_t cols, const Tile &initialTile): _rows_(rows), 
                                                             _cols_(cols), 
                                                             _initialTile_(initialTile)
    {
        mytiles = new Tile[_cols_ * _rows_];
        std::fill(&(mytiles[0]), &(mytiles[0]) + (_rows_ * 
                 _cols_sizeof(Tile)),_initialTile_);
    }

    Grid(const Grid &other): _rows_(other._rows_), _cols_(other._cols_), 
                             _initialTile_(other._initialTile_)
    {
        mytiles = new Tile[other._rows_ * other._cols_];
        std::copy(other.mytiles, other.mytiles + other._rows_ * other._cols_, mytiles);    
    }

    Grid::operator=(const Grid &other)
    {
        if (this == &other)
        {
            return *this;
        }
        _rows_ = other._rows_;
        _cols_ = other._cols_;
        _initialTile_ = other._initialTile_;
        mytiles = new Tile[other._rows_ * other._cols_];
        std::copy(other.mytiles, other.mytiles + other._rows_ * other._cols_, mytiles);
    }

    Grid(Grid &&other) noexcept: _rows_(std::move(other._rows_)), 
                                 _cols_(std::move(other._cols_)), 
                                 _initialTile_(std::move(other._initialTile_)), 
                                   mytiles(std::move(other.mytiles))
    {
        other.mytiles = nullptr;
    }

    Grid::operator=(Grid &&other) noexcept
    {
         _rows_= std::move(other._rows_);
         _cols_= std::move(other._cols_), 
         _initialTile_= std::move(other._initialTile_);
         delete[] mytiles;
         mytiles = std::move(other.mytiles);
         other.mytiles = nullptr;
         return *this;
    }

};

Tile is an enumertion:

enum Tile {
    See, Sky, Road
};

Tile tile_from_char(const char &c);

char char_from_tile(const Tile &t);

Thank you for your time and help.