Michael Marcin wrote:
Phil Endecott wrote:
Joel de Guzman wrote:
Phil Endecott wrote:
* xyz or [n] notation: using .x, .y and .z to access the coordinates seems simpler to me, but the higher-dimension people would prefer to use [0], [1] ... [n]. That notation also has the advantage that you can iterate through the dimensions. Is it possible to support both? Yes! Use fusion to do the mapping, making all your structs, arrays or whatnots, whatever they are, compatible.
I was imagining something more lightweight, like a union...
There's also the possibility of simply defining implicit conversions between the two styles.
But a better solution would be to decide from the outset that one style is "right" and the other is "wrong", so only one needs to be supported and no conversions are needed. (I mean that partly tongue-in-cheek.)
Have a look at:
http://www.gamedev.net/community/forums/topic.asp?topic_id=261920
Yes, a very good page showing several solutions: 1. A vector of member pointers (may have some overhead). 2. Anonymous structs and unions (may be non-standard). 3. x, y and z implemented as references (makes object bigger). 4. Relying on (&x)[1] pointing to y. _IF_ 4 really is guaranteed to work portably (as its author claims), it would get my vote: template <typename T> struct point2d { T x, y; T& operator[](int i) { return (&x)[i]; } }; ...what's the catch? One complexity is how point2d and point3d types like this would interoperate with a generic N-dimensional point: template <typename T, int N> struct point : public array<T,N> // or something like that Is it possible specialise point<T,N> for N==2 and N==3 to add the xyz stuff, and then typedef to the point2|3d names? Phil.