esp32 __attribute__ ((packed))
typedef struct { uint8_t type; uint8_t subType; uint16_t len; //network byte order: len[0] high byte, len[1] low byte for 16bit length uint16_t sn; char cc; }__attribute__ ((packed)) SESComHdr;
sizeof 输出7
typedef struct
{
uint8_t type;
uint8_t subType;
uint16_t len; //network byte order: len[0] high byte, len[1] low byte for 16bit length
uint16_t sn;
char cc;
}__attribute__ ((aligned(4))) SESComHdr;
输出8
typedef struct
{
uint8_t type;
uint8_t subType;
uint16_t len; //network byte order: len[0] high byte, len[1] low byte for 16bit length
uint16_t sn;
char cc;
}__attribute__ ((aligned(8))) SESComHdr;
sizeof 还是8