import a::*; import b::baz; mod a { impl foo for uint { fn plus() -> int { self as int + 20 } } } mod b { impl baz for str { fn plus() -> int { 200 } } } impl util for uint { fn str() -> str { uint::str(self) } fn times(f: fn(uint)) { let mut c = 0u; while c < self { f(c); c += 1u; } } } impl util for ~[T] { fn length_() -> uint { vec::len(self) } fn iter_(f: fn(T)) { for self.each |x| { f(x); } } fn map_(f: fn(T) -> U) -> ~[U] { let mut r = ~[]; for self.each |elt| { r += ~[f(elt)]; } r } } fn main() { impl foo for int { fn plus() -> int { self + 10 } } assert 10.plus() == 20; assert 10u.plus() == 30; assert "hi".plus() == 200; assert (~[1]).length_().str() == "1"; assert (~[3, 4]).map_(|a| a + 4 )[0] == 7; assert (~[3, 4]).map_::(|a| a as uint + 4u )[0] == 7u; let mut x = 0u; 10u.times(|_n| x += 2u ); assert x == 20u; }