- primarily for handling expression results,
but can also be used as a universal value holder.
Has some characteristics suitable for type-less IO:
eg, is_integral(), nComponents()
ENH: add is_pointer() check for expression scanToken
- use FACE_DATA (was SURFACE_DATA) for similarity with polySurface
ENH: add expression value enumerations and traits
- simple enumeration of standard types (bool, label, scalar, vector)
that can be used as a value type-code for internal bookkeeping.
GIT: relocate pTraits into general traits/ directory
