/// Allows Taffy to abstract of the types it uses to represent strings and calc expressions./// In future it may be extended to abstract the scalar number type (currently f32)pubtraitUnits{/// Trait that represents a cheaply clonable string. If you're unsure what to use here/// consider `Arc<str>` or `string_cache::Atom`.typeStr:CheapCloneStr;/// Type representing a calc expression./// If you're not using Calc then you can just use `()`typeCalc:'static;}pubstructDefaultUnits;implUnitsforDefaultUnits{typeStr =String;typeCalc =();}