Re: [boost] Bounded types (or maybe not 'bounded' anymore? ;-)

From: Rob Stewart (stewart_at_[hidden])
Date: 2005-09-28 12:44:11

From: "Robert Kawulak" <kawulak_at_[hidden]>
> 
> > >   initialize() - returns a value used to default-initialize 
> > a constrained
> > >     object;
> > 
> > It seems that you'd want it to take a non-const reference to
> > avoid copying.
> 
> I'm afraid i don't understand what you mean...

Use

   void initialize(value_type & value_o);

rather than

   value_type initialize();

Thus, when passed the data member to initialize, it can
initialize that object directly.  Granted, (N)RVO can often avoid
the copy, but this change will ensure you get the efficiency.

> > > BTW in the current version I've changed the name of 
> > basic_bounded template
> > > to constrained_type (I don't like constrained_value name 
> > which may be
> > > misleading, because it's a type of values rather than a 
> > value itself), and
> > 
> > I'm confused.  I thought the whole point of your library was to
> > create an object that *has* a value and to constrain that value
> > to be a member of a prescribed set.  That's how you can add them
> > together, increment them, etc.  Thus, "constrained_value" is
> > exactly the right name.
> 
> Putting it simply, point of my library is to provide templates of classes of
> objects having a value conforming to given constraints. constrained_type (or
> whatever we'll call it) is a type (class template to be strict), how can a
> type be named "something_value"? Now that's confusing to me... Maybe
> constrained_values_type would be the most appropriate ;-)

What you are suggesting is equivalent to suggesting that
std::vector should be named "vector_type" because it is a class
template.

The purpose of the class template is to create objects through
instantiating specializations.  It is those objects that are
actually used.  Thus, the type name should be indicative of the
purpose and use of those objects.  Those objects are values.  The
class name should indicate the value nature of those objects.

-- 
Rob Stewart                           stewart_at_[hidden]
Software Engineer                     http://www.sig.com
Susquehanna International Group, LLP  using std::disclaimer;