frumious hack for static typeclass methods

gistfile1.txt

iface builder<A> {
    // These "static" methods ignore their self parameter
    fn __new_container() -> self;
    fn __push(&_v: self, +_x: A);
}
impl extensions<A: copy> of builder<A> for ~[A] {
    fn __new_container() -> ~[A] { ~[] }
    fn __push(&v: ~[A], +x: A) { vec::push(v, x); } 
}

unsafe fn make_bs_builder<A,IA:builder<A>>() -> IA {
    unsafe::reinterpret_cast(ptr::null::<u8>())
}
// Pretend that these are static typeclass methods
fn new_container<A,IA:builder<A>>() -> IA {
    unsafe { make_bs_builder::<A,IA>().__new_container() }
}
fn push<A,IA:builder<A>>(&v: IA, +x: A) {
    unsafe { make_bs_builder::<A,IA>().__push(v, x) }
}

fn build_from_vec<A:copy,IA:builder<A>>(v: &[A]) -> IA {
    let mut new_v = new_container();
    for v.each() |x| {
        push(new_v, x);
    }
    ret new_v;
}


fn main() {
    let x: ~[int] = build_from_vec([1,2,3]/_);
    log(error, x);
}