pub trait AsAny {
// Required method
fn as_any(&self) -> &dyn Any;
}Expand description
Trait AsAny allows simple conversion of any type into a generic “thick”
pointer &dyn Any (see ::core::any::Any), that can be later converted
back to the original type with a graceful failing for all other conversions.
For simple conversions it is recommended to use #[derive(AsAny)] macro
from amplify_derive crate (see amplify_derive::AsAny).
§Example
ⓘ
#[macro_use]
extern crate amplify_derive;
extern crate amplify;
use amplify::AsAny;
#[derive(AsAny, Copy, Clone, PartialEq, Eq, Debug)]
struct Point {
pub x: u64,
pub y: u64,
}
#[derive(AsAny, PartialEq, Debug)]
struct Circle {
pub radius: f64,
pub center: Point,
}
let mut point = Point { x: 1, y: 2 };
let point_ptr = point.as_any();
let mut circle = Circle {
radius: 18.,
center: point,
};
let circle_ptr = circle.as_any();
assert_eq!(point_ptr.downcast_ref(), Some(&point));
assert_eq!(circle_ptr.downcast_ref(), Some(&circle));
assert_eq!(circle_ptr.downcast_ref::<Point>(), None);
let p = point_ptr.downcast_ref::<Point>().unwrap();
assert_eq!(p.x, 1)