rust-lang/rust — pull request #16626 by ruud-v-a (2014-08-20 12:39:52+00:00)
Title: libstd: Refactor Duration.

This changes the internal representation of `Duration` from

days: i32,
secs: i32,
nanos: u32

to

secs: i64,
nanos: i32

This resolves #16466. Note that `nanos` is an `i32` and not `u32` as suggested, because `i32` is easier to deal with, and it is not exposed anyway. Some methods now take `i64` instead of `i32` due to the increased range. Some methods, like `num_milliseconds`, now return an `Option` instead of `i64`, because the range of `Duration` is now larger than e.g. 2^63 milliseconds.

A few remarks:
- Negating `MIN` is impossible. I chose to return `MAX` as `-MIN`, but it is one nanosecond less than the actual negation. Is this the desired behaviour?
- In `std::io::timer`, some functions accept a `Duration`, which is internally converted into a number of milliseconds. However, the range of `Duration` is now larger than 2^64 milliseconds. There is already a FIXME in the file that this should be addressed (without a ticket number though). I chose to silently use 0 ms if the duration is too long. Is that right, as long as the backend still uses milliseconds?
- Negative durations are not formatted correctly, but they were not formatted correctly before either.