At the moment, with the major use case, which is playing back glTF
animations, one can't use atStrict() because there Extrapolation is
specified to be always Constant. The atStrict() function behaves as
Extrapolate and one would need to patch the imported tracks to add
explicit keyframes at the beginning/end of the duration that emulate the
Constant behavior.
I managed to work around that for Emscripten 1.38.5 by adding an
explicit definition of noexcept Player::Track copy
constructor/assignment, but that didn't solve anything for Emscripten,
iOS or Android. Since I can't reproduce that on *anything* I have on
this machine and it seems that the problem somehow just goes away when
using a more recent Clang, I decided to just remove the noexcept
specifier altogether.
I had a temptation to make it noexcept everywhere except Clang, but that
might add potential portability issues (code that works with GCC would
suddenly break on Clang without any clear reason).
Vladimír Vondruš