C++編譯器(特別是g ++)是否可以重新排序結構的內部元素?C++編譯器是否可以重新排序結構中的元素
我看到一些奇怪的行爲,我有一個包含類似如下結構:
Struct SomeStruct{
...
...
long someLong;
long someLongArray[25];
unsigned long someUnsignedLong;
unsigned long someUnsignedLongArray[8];
unsigned long int someUnsignedLongInt;
...
...
};
當我寫這個輸出到文件,someUnsignedLongArray和someLongArray的順序似乎在被反轉(即,元件someLongArray []出現後someUnsignedLong和someUnsignedLongArray []後索姆出現的元素eLong)。這可能嗎??
感謝
更新:
int fd = open(fspec,O_RDWR|O_CREAT|O_TRUNC,0666);
int writeRes = write(fd,(char *)&someStruct,sizeof(SomeStruct));
爲了完整起見,這裏是完整的結構:
struct SomeStruct{
byte someByte;
byte someByteArray[6];
char someChar;
char someCharArray[5];
char someCharArrayArray[3][5];
short someShort;
signed short someShortArray[2];
unsigned short someUnsignedShort;
unsigned short someUnsignedShortArray[8];
int someInt;
int someIntArray[3];
int someIntArrayArrayArrayArray[4][3][2][6];
int *pSomeInt;
unsigned int someUnsignedInt;
unsigned int someUnsignedIntArray[9];
long someLong;
long someLongArray[25];
unsigned long someUnsignedLong;
unsigned long someUnsignedLongArray[8];
unsigned long int someUnsignedLongInt;
long long someLongLong;
long long someLongLongArray[5];
bool someBool;
bool someBoolArray[3];
unsigned long long someUnsignedLongLong;
unsigned long long someUnsignedLongLongArray[5];
unsigned long long someUnsignedLongLongArrayArray[5][2];
unsigned long long int *pSomeUnsignedLongLongInt;
};
你怎麼寫的結構到一個文件? – tstenner 2009-05-27 16:18:54
你確定你看到你認爲你看到了嗎?ie你是否在每個元素中寫入了獨特的位模式,並且可以將它們跟蹤到文件中?還有,你在結構體周圍使用了什麼樣的#pragma pack(如果有的話)? – 2009-05-27 16:29:52
也許他正在將結構的字節而不是結構的元素寫入文件。 – pyon 2009-05-27 16:31:27