intptr_t、uintptr_t数据类型

在64位的机器上，intptr_t和uintptr_t分别是long int、unsigned long int的别名；在32位的机器上，intptr_t和uintptr_t分别是int、unsigned int的别名。

/* Types for `void *' pointers.  */
#if __WORDSIZE == 64
# ifndef __intptr_t_defined
typedef long int		intptr_t;
#  define __intptr_t_defined
# endif
typedef unsigned long int	uintptr_t;
#else
# ifndef __intptr_t_defined
typedef int			intptr_t;
#  define __intptr_t_defined
# endif
typedef unsigned int		uintptr_t;
#endif

参考资料：https://blog.csdn.net/cs_zhanyb/article/details/16973379