Error handling

[Uriopass]

Sometimes parameter don't make sense: negative radius, flex=0 for a spacer.

I also think of infinitely sized objects that can crash the painter in debug (overflow error when building the rect).

What should be the strategy to help the user?

I can think of a few ways:

• debug_assert! or log::error at the right places
• Newtypes like NonZeroX or PositiveX (not very ergonomic)
• Some kind of debug mode, like an inspector that could highlight issues/sizes/constraints