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#define STATIC_ASSERT(condition) \
int some_array##__LINE__[(condition) ? 1 : -1]
struct Z1
{
char ch;
int i:3;
char ch2;
// there is end-of-struct padding because of the int
};
STATIC_ASSERT(_Alignof(struct Z1) == _Alignof(int));
#ifdef _MSC_VER
STATIC_ASSERT(sizeof(struct Z1) == 4 + 4 + 4);
#else
STATIC_ASSERT(sizeof(struct Z1) == 1 + 1 + 1 + 1);
#ifdef __GNUC__
STATIC_ASSERT(__builtin_offsetof(struct Z1, ch2) == 2);
#endif
#endif
#pragma pack(push, 1)
struct Z1_packed
{
char ch;
int i : 3;
char ch2;
// there is no end-of-struct padding
};
#pragma pack(pop)
STATIC_ASSERT(_Alignof(struct Z1_packed) == 1);
#ifdef _MSC_VER
STATIC_ASSERT(sizeof(struct Z1_packed) == 1 + 4 + 1);
#else
STATIC_ASSERT(sizeof(struct Z1_packed) == 1 + 1 + 1);
#ifdef __GNUC__
STATIC_ASSERT(__builtin_offsetof(struct Z1_packed, ch2) == 2);
#endif
#endif
struct Z2
{
char ch;
char i:3;
char ch2;
// there is no end-of-struct padding
};
STATIC_ASSERT(sizeof(struct Z2) == 1 + 1 + 1);
#pragma pack(push, 1)
struct Z2_packed
{
char ch;
char i : 3;
char ch2;
// there is no end-of-struct padding
};
#pragma pack(pop)
STATIC_ASSERT(sizeof(struct Z2_packed) == 1 + 1 + 1);
struct Z3
{
char ch;
int i : 3; // padded by MSVC, not by gcc/clang
};
#ifdef _MSC_VER
STATIC_ASSERT(sizeof(struct Z3) == 4 + 4);
#else
STATIC_ASSERT(sizeof(struct Z3) == 1 + 1 + 2);
#endif
#pragma pack(push, 1)
struct Z3_packed
{
char ch;
int i : 3; // padded by MSVC, not by gcc/clang
};
#pragma pack(pop)
#ifdef _MSC_VER
STATIC_ASSERT(sizeof(struct Z3_packed) == 1 + 4);
#else
STATIC_ASSERT(sizeof(struct Z3_packed) == 1 + 1);
#endif
struct Z4
{
int i;
long long int x; // pads to 8
char ch; // 7 end-of-struct padding
};
STATIC_ASSERT(sizeof(struct Z4) == 4 + 4 + 8 + 1 + 7);
#pragma pack(push, 1)
struct Z4_packed
{
int i;
long long int x; // no padding
char ch; // no end-of-struct padding
};
#pragma pack(pop)
STATIC_ASSERT(sizeof(struct Z4_packed) == 4 + 8 + 1);
struct Z5
{
char ch;
long long int x[]; // pads to 8, but has no size
};
STATIC_ASSERT(sizeof(struct Z5) == 8);
#pragma pack(push, 1)
struct Z5_packed
{
char ch;
long long int x[]; // pads to 8, but has no size
};
#pragma pack(pop)
STATIC_ASSERT(sizeof(struct Z5_packed) == 1);
struct Z6
{
char ch;
int i : 16; // padded to int by MSVC, to short by gcc/clang
};
#ifdef _MSC_VER
STATIC_ASSERT(sizeof(struct Z6) == 4 + 4);
#else
STATIC_ASSERT(sizeof(struct Z6) == 1 + 1 + 2);
#endif
#pragma pack(push, 1)
struct Z6_packed
{
char ch;
int i : 16; // padded to int by MSC, but not aligned
};
#pragma pack(pop)
#ifdef _MSC_VER
STATIC_ASSERT(sizeof(struct Z6_packed) == 1 + 4);
#else
STATIC_ASSERT(sizeof(struct Z6_packed) == 1 + 2);
#endif
int main()
{
}
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