-#define MESSAGE_HANDSHAKE_SIZE 68
-#define MESSAGE_CHOKE_SIZE 5
-#define MESSAGE_UNCHOKE_SIZE 5
-#define MESSAGE_INTERESTED_SIZE 5
-#define MESSAGE_NOTINTERESTED_SIZE 5
-#define MESSAGE_HAVE_SIZE 9
-#define MESSAGE_BITFIELD_SIZE 5
-#define MESSAGE_REQUEST_SIZE 17
-#define MESSAGE_PIECE_SIZE 13
-#define MESSAGE_CANCEL_SIZE 17
+constexpr unsigned MESSAGE_HANDSHAKE_SIZE = 68;
+constexpr unsigned MESSAGE_CHOKE_SIZE = 5;
+constexpr unsigned MESSAGE_UNCHOKE_SIZE = 5;
+constexpr unsigned MESSAGE_INTERESTED_SIZE = 5;
+constexpr unsigned MESSAGE_NOTINTERESTED_SIZE = 5;
+constexpr unsigned MESSAGE_HAVE_SIZE = 9;
+constexpr unsigned MESSAGE_BITFIELD_SIZE = 5;
+constexpr unsigned MESSAGE_REQUEST_SIZE = 17;
+constexpr unsigned MESSAGE_PIECE_SIZE = 13;
+constexpr unsigned MESSAGE_CANCEL_SIZE = 17;