17. Binary to Gray Code Converter

How do you plan to solve it?

module bin2gray4 (
    input [3:0] bin_in,
    output [3:0] gray_out
);
    assign gray_out = bin_in ^ (bin_in >> 1);
//    assign gray_out[3] = bin_in[3];
//    assign gray_out[2] = bin_in[3] ^ bin_in[2];
//    assign gray_out[1] = bin_in[2] ^ bin_in[1];
//    assign gray_out[0] = bin_in[1] ^ bin_in[0];
endmodule