rust/src/test/run-pass/nullable-pointer-iotareduction.rs
2013-05-03 20:01:42 -04:00

88 lines
2.7 KiB
Rust

// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use core::{option, cast};
// Iota-reduction is a rule in the Calculus of (Co-)Inductive Constructions,
// which "says that a destructor applied to an object built from a constructor
// behaves as expected". -- http://coq.inria.fr/doc/Reference-Manual006.html
//
// It's a little more complicated here, because of pointers and regions and
// trying to get assert failure messages that at least identify which case
// failed.
enum E<T> { Thing(int, T), Nothing((), ((), ()), [i8, ..0]) }
impl<T> E<T> {
fn is_none(&self) -> bool {
match *self {
Thing(*) => false,
Nothing(*) => true
}
}
fn get_ref<'r>(&'r self) -> (int, &'r T) {
match *self {
Nothing(*) => fail!(fmt!("E::get_ref(Nothing::<%s>)", stringify!($T))),
Thing(x, ref y) => (x, y)
}
}
}
macro_rules! check_option {
($e:expr: $T:ty) => {{
// FIXME #6000: remove the copy
check_option!(copy $e: $T, |ptr| assert!(*ptr == $e));
}};
($e:expr: $T:ty, |$v:ident| $chk:expr) => {{
assert!(option::None::<$T>.is_none());
let s_ = option::Some::<$T>($e);
let $v = s_.get_ref();
$chk
}}
}
macro_rules! check_fancy {
($e:expr: $T:ty) => {{
// FIXME #6000: remove the copy
check_fancy!(copy $e: $T, |ptr| assert!(*ptr == $e));
}};
($e:expr: $T:ty, |$v:ident| $chk:expr) => {{
assert!(Nothing::<$T>((), ((), ()), [23i8, ..0]).is_none());
let t_ = Thing::<$T>(23, $e);
match t_.get_ref() {
(23, $v) => { $chk }
_ => fail!(fmt!("Thing::<%s>(23, %s).get_ref() != (23, _)",
stringify!($T), stringify!($e)))
}
}}
}
macro_rules! check_type {
($($a:tt)*) => {{
check_option!($($a)*);
check_fancy!($($a)*);
}}
}
pub fn main() {
check_type!(&17: &int);
check_type!(~18: ~int);
check_type!(@19: @int);
check_type!(~"foo": ~str);
check_type!(@"bar": @str);
check_type!(~[]: ~[int]);
check_type!(~[20, 22]: ~[int]);
check_type!(@[]: @[int]);
check_type!(@[24, 26]: @[int]);
let mint: uint = unsafe { cast::transmute(main) };
check_type!(main: extern fn(), |pthing| {
assert!(mint == unsafe { cast::transmute(*pthing) })
});
}