If you want to turn all the bits on, a portable way to do this is to define a signed long constant with a value of -1.

如果我们希望所有位全部置位，那么一种可移植的方法是定义一个有符号的常数，其值为- 1。

youdao

If you want to turn all the bits on, a portable way to do this is to define a signed long constant with a value of -1.

如果我们希望所有位全部置位，那么一种可移植的方法是定义一个有符号的常数，其值为- 1。

youdao