Impl Default for Coordinates

[sbland]

Can we safely implement default for the Coordinate struct as below:

impl<T: Default + CoordNum> Default for Coordinate<T> {
    fn default() -> Coordinate<T> {
        Coordinate {
            x: T::default(),
            y: T::default(),
        }
    }
}

[frewsxcv]

It is possible to add this implementation. @sbland Would you mind sharing your use case for this?

[sbland]

@frewsxcv I have many structs that use the Point struct and can otherwise implement default with #[derive(Default)]. Their initial position is not important and will be set later. See below for example of code that would be simplified by including a default implementation of Point:

// #[derive(Default)
pub struct CellState {
    pub id: u32,
    pub position: Point<f64>,
    pub population: u32,
}

// All this could be removed if Point had a default implementation
impl Default for CellState {
    fn default() -> CellState {
        CellState {
            id: 0,
            position: point!(x:0.0, y:0.0),
            population: 0,
        }
    }
}

I can submit a quick PR if there are no potential issues to this.

[michaelkirk]

You probably already know, but just in case, to get defaults for the other fields you can write:

CellState {          
    position: point!(x:0.0, y:0.0),
    ..Default::default()
}

I can submit a quick PR if there are no potential issues to this.

There is always potential for issues 😉, but I think relying on T::Default seems pretty reasonable - for 99.9% of people, that means they'll get a point at (0,0).

[sbland]

Thanks @michaelkirk I use this for instantiating later but still need to put in position: point!(x:0.0, y:0.0), every time.
I'll submit the PR and see if anyone complains :).

[frewsxcv]

Done in #616