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

From: Robert Kawulak (kawulak_at_[hidden])
Date: 2005-09-28 15:59:07

Hi, 

> 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.

I don't think so, because your version of initialize couldn't be used to
initialize a value in constructor's initialization list. So first the value
would be default-constructed, and then assigned another value using
initialize.
In bounded policies I use
  passed_value_type initialize()
where passed_value_type is value_type for integral types and const
value_type & for other types. The second returns a reference to a static
object - that's the most efficient method I can think of, initialization
takes only one copy-construction (for details please look into the code).

> > 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.

Uhh, maybe you're right ;-) I don't know why, but it just "byte my eyes"
when I see a type named "something_value"... Nevermind, if people here
really resist that it should be called constrained_value instead of
constrained_type, then OK - I'll change it.

Best regards,
Robert