C++-ize W6300 driver: remove vtable indirection, constexpr pins, pragma once

w6300/socket.h

@@ -1,9 +1,4 @@
-#ifndef _SOCKET_H_
-#define _SOCKET_H_
-#ifdef __cplusplus
-extern "C" {
-#endif
-
+#pragma once
 #include "wizchip_conf.h"
 
 #define SOCKET                uint8_t
@@ -123,8 +118,3 @@ int32_t recvfrom_W6x00(uint8_t sn, uint8_t * buf, uint16_t len, uint8_t * addr,
 #define sendto(sn, buf, len, addr, port, addrlen) sendto_W6x00(sn, buf, len, addr, port, addrlen)
 #define recvfrom(sn, buf, len, addr, port, addrlen) recvfrom_W6x00(sn, buf, len, addr, port, addrlen)
 
-#ifdef __cplusplus
-}
-#endif
-
-#endif