test.rs

use std::io;
use std::str;

trait Eq2<RHS> {
    fn eq2(&self, rhs: RHS) -> bool;
}

////

trait IntEq2 {
    fn eq2_to_int(&self, lhs: int) -> bool;
}

impl<RHS: IntEq2> Eq2<RHS> for int {
    fn eq2(&self, rhs: RHS) -> bool { rhs.eq2_to_int(*self) }
}

impl IntEq2 for i8 {
    fn eq2_to_int(&self, lhs: int) -> bool { lhs == *self as int }
}

impl IntEq2 for i16 {
    fn eq2_to_int(&self, lhs: int) -> bool { lhs == *self as int }
}

////

trait StrEq2 {
    fn eq2_to_str(&self, lhs: &str) -> bool;
}

impl<'self, RHS: StrEq2> Eq2<RHS> for &'self str {
    fn eq2(&self, rhs: RHS) -> bool { rhs.eq2_to_str(*self) }
}

impl StrEq2 for ~str {
    fn eq2_to_str(&self, lhs: &str) -> bool { str::eq_slice(lhs, *self) }
}

impl<'self> StrEq2 for &'self str {
    fn eq2_to_str(&self, lhs: &str) -> bool { str::eq_slice(lhs, *self) }
}

////

fn main() {
    io::println(fmt!("%?", (5).eq2(5i8)));
    io::println(fmt!("%?", (5).eq2(5i16)));

    io::println(fmt!("%?", (~"abc").eq2("abc")));
    io::println(fmt!("%?", ("abc").eq2(~"abc")));
}