Add width getter function for HyperCube

[mforets]

No description provided.

[SimonDanisch]

That seems to be exactly the same definition as widths?

[SimonDanisch]

Ah, sorry.. I forgot that HyperCube does actually store it's width as a single float...
Hm, i'm still not sure if I like that definition :D Seems a bit ambigious - maybe this doesn't need to be a function, and if one has a hypercube, one should just access the field?
We usually only need to have this defined as a function, if we plan to follow an interface that spans multiple types... But I don't really see how the definition of width can easily span over other multi dimensional geometry types ;)

[mforets]

one should just access the field?

If you decide to change the internal representation, or field names of the HyperCube in the future, downstream code accessing the field directly will break. If a getter function is provided, this is less likely. That was the motivation for this PR :) I can do widths(X)[1] but that creates an unnecessary 3d vector.

[sjkelly]

I think this is okay since widths gives a vector and width a scalar. You could feasibly define width for other equally-sized geometries such as HyperSpheres and n-gons.

[SimonDanisch]

Well, I guess we can add this ;)

[SimonDanisch]

Maybe not export it, since it seems like a widely used function^^

[mforets]

Bump?

You could feasibly define width for other equally-sized geometries such as HyperSpheres

fwiw, HyperSpheres have a radius getter function.

Maybe not export it,

I didn't add any export statement in this branch, but width is already exported (https://github.com/JuliaGeometry/GeometryTypes.jl/blob/master/src/GeometryTypes.jl#L186).

[SimonDanisch]

Oh well^^ Lets merge it then ;)