#include struct Bits { uint32_t : 1; uint32_t b1 : 1; uint32_t b2 : 2; uint32_t : 2; uint32_t b3 : 3; // Unnamed bitfield (this will get removed). uint32_t : 2; uint32_t b4 __attribute__ ((aligned(16))); uint32_t b5 : 5; uint32_t b6 : 6; uint32_t b7 : 7; uint32_t four : 4; }; struct MoreBits { uint32_t a : 3; uint8_t : 1; uint8_t b : 1; uint8_t c : 1; uint8_t d : 1; }; struct MoreBits more_bits; struct ManySingleBits { uint16_t b1 : 1, b2 : 1, b3 : 1, b4 : 1, b5 : 1, b6 : 1, b7 : 1, b8 : 1, b9 : 1, b10 : 1, b11 : 1, b12 : 1, b13 : 1, b14 : 1, b15 : 1, b16 : 1, b17 : 1; }; struct ManySingleBits many_single_bits; struct LargePackedBits { uint64_t a : 36; uint64_t b : 36; } __attribute__((packed)); #pragma pack(1) struct PackedBits { char a; uint32_t b : 5, c : 27; }; #pragma pack() int main(int argc, char const *argv[]) { struct Bits bits; bits.b1 = 1; bits.b2 = 3; bits.b3 = 7; bits.b4 = 15; bits.b5 = 31; bits.b6 = 63; bits.b7 = 127; bits.four = 15; more_bits.a = 3; more_bits.b = 0; more_bits.c = 1; more_bits.d = 0; many_single_bits.b1 = 1; many_single_bits.b5 = 1; many_single_bits.b7 = 1; many_single_bits.b13 = 1; struct PackedBits packed; packed.a = 'a'; packed.b = 10; packed.c = 0x7112233; struct LargePackedBits large_packed = (struct LargePackedBits){0xcbbbbaaaa, 0xdffffeeee}; struct LargePackedBits *large_packed_ptr = &large_packed; return 0; // break here }