I cannot figure this trait out

[AhmedSalih3d]

Hello!

I am using a plotting package, https://crates.io/crates/charts, and I am having some problems making it understand how to understand a specific trait. It is giving me an error:

.load_data(&scatter_data_1)
   |                    ^^^^^^^^^^^^^^^ the trait `charts::PointDatum<f32, f32>` is not implemented for `nalgebra::Point<f32, nalgebra::U3>`

And basically what I have been doing is then:

use nalgebra::{Point3};
impl charts::PointDatum<f32, f32> for Point3<f32> {
    fn get_x(&self) -> f32 {
        self.coords[0]
    }

    fn get_y(&self) -> f32 {
        self.coords[2]
    }

    fn get_key(&self) -> String {
        String::new()
    }
}

This gives the error:

only traits defined in the current crate can be implemented for arbitrary types

impl doesn't use only types from inside the current crate

note: define and implement a trait or new type insteadrustc(E0117)

So I have tried looking E0117 up to circumvent this problem, but my tries up till now has not been succesful. I have written it as:

struct MyType(Point3<f32>);
impl charts::PointDatum<f32, f32> for MyType {
    fn get_x(&self) -> f32 {
        self.0.coords[0]
    }

    fn get_y(&self) -> f32 {
        self.0.coords[2]
    }

    fn get_key(&self) -> String {
        String::new()
    }
}

But I still get the first mentioned error that for some reason it cannot figure out that "Point3<f32" == MyType now..

Maybe I am doing something wrong still.

Kind regards

[jethrogb]

If you want to equate values of types Point3<f32> and MyType, you'll need to implement PartialEq.

[MrTact]

And probably From to make it easier to cast between them.

[AhmedSalih3d]

Thank you to both of you.