Geometry Boost List: [geometry] Breaking change on distance strategies

Subject: [geometry] Breaking change on distance strategies
From: Bruno Lalande (bruno.lalande_at_[hidden])
Date: 2013-07-14 18:55:14

Hi,

FYI, I have just submitted a change (85040) that breaks the interface of
the distance strategies. Generally speaking, the change is that those
strategies no longer need to be templated with the point type - a strategy
can work on any point type once instantiated. More specifically:
- pythagoras<Point1, Point2, CalculationType> becomes
pythagoras<CalculationType>
- haversine<Point1, Point2, CalculationType> becomes haversine<RadiusType,
CalculationType> - the RadiusType parameter will typically be the points'
coordinate type, but you might choose something else e.g. for performance
reasons
- projected_point<Point, PointOfSegment, CalculationType, Strategy> becomes
projected_point<CalculationType, Strategy>
- cross_track<Point, PointOfSegment, CalculationType, Strategy> becomes
cross_track<CalculationType, Strategy>

Of course this doesn't impact you if you never explicitly specify a
strategy to use for distance calculations (i.e. if you rely on the default
ones).

If you write your own strategies, the impact might be more important. The
most noticeable internal change is that similar_type/get_similar disappear,
as this change makes them irrelevant.

The plan is to give the same treatment to the other strategies of the
library.

Regards
Bruno