Re: [boost] Geometry Template Library from Intel

From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2008-05-01 06:33:13

Simonson, Lucanus J wrote:
> For me, requiring a point concept that a has an x() and y() member
> functions is unnecessary and restricts the usefulness of the library.  I
> could obviously make such a requirement, but I would prefer to have
> adaptor functions such as:
> coordinate_type point_interface<T>::getX(const T& point);
> which allows compatibility with anyone's point concept

> Shouldn't generic code ideally work with any type that is
> conceptually a point, rather than only types that model the point
> concept they set forth?

You should be able to express this something like "Type T models the 
Point Concept if there exists a specialisation point_interface<T> 
having members ....".  Can you write a definition like that?

I think it would be an interesting thought-experiment to consider how 
the standard library would look if re-written in this style, e.g. not 
using std::pair in maps.

There are three groups of people affected:

- Users with legacy code, who benefit.
- Users without legacy code, who have a (perhaps small) extra step on 
their learning curve.
- People writing libraries, who have more work to do.

Phil.