In languages that don't allow underscores in integer literals, is it a good idea to create a constant for 1 billion?  e.g. in C++:

size_t ONE_BILLION = 1000000000;


Certainly, we shouldn't create constants for small numbers like 100.  But with 9 zeros, it's arguably easy to leave off a zero or add an extra one in code like this:

tv_sec = timeInNanosec / 1000000000;
tv_nsec = timeInNanosec % 1000000000;


Create one called NANOSECONDS_IN_ONE_SECOND instead as that what it represents.

Or a shorter, better name if you can think of one.
