内存字节对齐

 

 

#pragma pack(8)struct A{char a;short b;};struct B{char c;A d;long long e;};#pragma pack() 

A stA;B stB;stB.c = 1;stB.d.a = 2;stB.d.b = 3;stB.e = 4;A *pA = &stA;B *pB = &stB;sizeof(A);sizeof(B);

sizeof(A) ：4

sizeof(B) ：16

 

B的内存：01 cc 02 cc 03 00 cc cc 04 00 00 00 00 00 00 00

 

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#pragma pack(8)struct A{char a;long b;};struct B{char c;A d;long long e;};#pragma pack() 

A stA;B stB;stB.c = 1;stB.d.a = 2;stB.d.b = 3;stB.e = 4;A *pA = &stA;B *pB = &stB;sizeof(A);sizeof(B); 

 

 

sizeof(A) ：8

sizeof(B) ：24

B的内存：01 cc cc cc 02 cc cc cc 03 00 00 00 cc cc cc cc 04 00 00 00 00 00 00 00