foo.rs

/*

Tests the Any trait.

*/

pub struct Player {
	name: ~str
}

pub struct Enemy {
	name: ~str
}

pub trait Entity {
	fn get_name<'a>(&'a self) -> &'a str;
}

impl Entity for Player {
	fn get_name<'a>(&'a self) -> &'a str {
		self.name.as_slice()
	}
}

impl Entity for Enemy {
	fn get_name<'a>(&'a self) -> &'a str {
		self.name.as_slice()
	}
}

fn create_player(name: ~str) -> ~Entity {
	~Player { name: name } as ~Entity
}

fn main() {
	// The following works:
	// let player = ~Player { name: ~"player1" } as ~Any;

	// The following does not work:
	// Player is ~Entity.
	let player = create_player(~"player1") as ~Any;

	// How to make 'is' work?
	let x = player;
	if x.is::<Player>() {
		let y = x.as_ref::<Player>().unwrap();
		println!("{}", y.get_name());	
	}	
}

// COMPILER ERROR

error: can only cast an ~-pointer to a ~-object, not a trait Entity
any.rs:42 	let player = create_player(~"player1") as ~Any;
          	             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~