From: Haim Cohen <haim.cohen@analog.com>
First of all, my first comment is about the library's name, as well as the class name. In logic circuit simulation, there are 4 values : 0, 1, x ( which is tribool referred to as undetermine ), and z ( represents high impedance - or disconnection, and sometime referred to as "tri state" ). So, I think users will find it quite confusing when they see the 'tri' in the library's name. Since the library implements a logic value which has some value that is unknown, I would suggest 'unknown bool' or 'x bool'.
First, you say that the indeterminate value should be named "x" because "x" is the indeterminate state in electronics. When looking for a non-descriptive identifier, one often resorts to things like "x," so there's some programming precedent for "x" meaning "arbitrary value." However, "indeterminate" leaves no doubt as to the meaning of the value and doesn't depend upon one's experience with electronics. Another possibility would be "unknown" as that is equally descriptive and is definitely shorter (less typing!). Second, you say that the library name should not be "tribool" but instead should be "unknown_bool" or "x_bool" to avoid confusion with tristate logic. Do you seriously think electronics domain programmers will think that "boost::tribool" is related to tristate logic? I don't see that as likely. That doesn't mean there isn't value in your suggestion to change the library name. As I've already rejected the "x" notion, that leaves "unknown_bool" or, by extension, "indeterminate_bool." While these names suggest that there is an unknown or indeterminate Boolean value, they don't suggest to me a type that includes true, false, *and* unknown/indeterminate. "tribool," OTOH, clearly indicates that it is a type that includes exactly three logic states, though it doesn't name any of them. Furthermore, "tribool" paves the way for the possibility of adding quadbool or multibool to Boost. -- Rob Stewart stewart@sig.com Software Engineer http://www.sig.com Susquehanna International Group, LLP using std::disclaimer;