时间设计原理(2)

Design rationale for time(2)

If tloc is non-NULL, the return value is also stored in the memory pointed to by tloc.

问题:为什么要将值存储在 return 值以外的其他地方?这是某种历史遗迹吗?

显然是遗物:

The tloc argument is obsolescent and should always be NULL in new code.

但这提出了一个问题,为什么它首先是这样设计的。