#include <iostream>
using namespace std;
#include <stdint.h>
#include <stdio.h>
 
typedef struct structTag {
  union {
    struct {
      uint32_t messageID : 26; /* 26bit message id, 67108864 ids */
      uint8_t priority : 3; /* priority: MUST BE 0 */
    } __attribute__ ((packed));
    struct {
      uint32_t rawID : 29;
      uint8_t canFlags : 3;
    };
  } __attribute__ ((packed));
} __attribute__ ((packed)) idSpecial;
 
int main() {
	printf("size: %d", sizeof(idSpecial));
	return 0;
}

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