Like the Deg / Rad classes, these are for strongly-typed representation
of time. Because the current way, either with untyped and imprecise
Float, or the insanely-hard-to-use and bloated std::chrono::nanoseconds,
was just too crappy.
This is just the types alone, corresponding typedefs in the root
namespace, and conversion from std::chrono. Using these in the Animation
library, in Timeline, in DebugTools::FrameProfiler, GL::TimeQuery etc.,
will eventually and gradually follow.
Vladimír Vondruš