c宏定义的技巧总结

http://blog.csdn.net/eroswang/archive/2009/06/12/4265046.aspx
1,防止一个头文件被重复包含
#ifndef COMDEF_H
#define COMDEF_H
//头文件内容
#endif
2,重新定义一些类型,防止由于各种平台和编译器的不同,而产生的类型字节数差异,方便移植。
typedef unsigned char      boolean;     /* Boolean value type. */
typedef unsigned long int uint32;      /* Unsigned 32 bit value */
typedef unsigned short     uint16;      /* Unsigned 16 bit value */
typedef unsigned char      uint8;       /* Unsigned 8 bit value */
typedef signed long int    int32;       /* Signed 32 bit value */
typedef signed short       int16;       /* Signed 16 bit value */
typedef signed char        int8;        /* Signed 8 bit value */
//下面的不建议使用
typedef unsigned char     byte;         /* Unsigned 8 bit value type. */
typedef unsigned short    word;         /* Unsinged 16 bit value type. */
typedef unsigned long     dword;        /* Unsigned 32 bit value type. */
typedef unsigned char     uint1;        /* Unsigned 8 bit value type. */
typedef unsigned short    uint2;        /* Unsigned 16 bit value type. */
typedef unsigned long     uint4;        /* Unsigned 32 bit value type. */
typedef signed char       int1;         /* Signed 8 bit val