man*_*m-n 2 c c++ macros typedef c-preprocessor
从头文件ncurses.h,#if我认为有什么用处#if 0将始终返回false并且控件总是会出现这个#else部分？
#if 0 && defined(_LP64)
typedef unsigned chtype;
typedef unsigned mmask_t;
#else
typedef unsigned long chtype;
typedef unsigned long mmask_t;
#endif