#include #include typedef struct { uint8_t one: 1; } __attribute__ ((packed)) one; typedef struct { uint16_t one: 1; } __attribute__ ((packed)) two; typedef struct { unsigned int one: 1; } __attribute__ ((packed)) three; int main(void) { printf("%d\n", sizeof(one)); printf("%d\n", sizeof(two)); printf("%d\n", sizeof(three)); };