机器平台：X86_64 处理器
操作系统：Red Hat 4.1.2-14
编译器： gcc version 4.1.2 20070626
Size of char is: 1
Size of unsigned char is: 1
Size of signed char is: 1
Size of int is: 4
Size of short is: 2
Size of long is: 8
Size of long int is: 8
Size of signed int is: 4
Size of unsigned int is: 4
Size of unsigned long int is: 8
Size of long long int is: 8
Size of unsigned long long is: 8
Size of float is: 4
Size of double is: 8
Size of long double is: 16
Size of (void *) is: 8
Size of (char *) is: 8
Size of (int *) is: 8
Size of (long *) is: 8
Size of (long long *) is: 8
Size of (float *) is: 8
Size of (double *) is: 8
——————————————————————————
机器平台： X86_32 处理器
操作系统： Windows XP SP2
编译器： VS2005自带的C++编译器
Size of char is: 1
Size of unsigned char is: 1
Size of signed char is: 1
Size of int is: 4
Size of short is: 2
Size of long is: 4
Size of long int is: 4
Size of signed int is: 4
Size of unsigned int is: 4
Size of unsigned long int is: 4
Size of long long int is: 8
Size of unsigned long long is: 8
Size of float is: 4
Size of double is: 8
Size of long double is: 8
Size of (void *) is: 4
Size of (char *) is: 4
Size of (int *) is: 4
Size of (long *) is: 4
Size of (long long *) is: 4
Size of (float *) is: 4
Size of (double *) is: 4
其实就是所有的指针扩充为8位，long 变为8位， long doulbe 变为16位，注意double 是没有变化的
double* (*a)[3][6];
cout<<sizeof(a)<<endl; // 4
cout<<sizeof(*a)<<endl; // 72
cout<<sizeof(**a)<<endl; // 24
cout<<sizeof(***a)<<endl; // 4
cout<<sizeof(****a)<<endl; // 8
