rust/src/test/compile-fail/region-borrow-params-issue-29793-big.rs
2017-12-15 13:52:05 -08:00

91 lines
2.4 KiB
Rust

// Copyright 2015 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.
// Issue #29793, big regression test: do not let borrows of
// parameters to ever be returned (expanded with exploration of
// variations).
//
// This is the version of the test that actually exposed unsound
// behavior (because the improperly accepted closure was actually
// able to be invoked).
// ignore-tidy-linelength
// revisions: ast mir
//[mir]compile-flags: -Z borrowck=mir
struct WrapA<F>(Option<F>);
impl<F> WrapA<F> {
fn new() -> WrapA<F> {
WrapA(None)
}
fn set(mut self, f: F) -> Self {
self.0 = Some(f);
self
}
}
struct WrapB<F>(Option<F>);
impl<F> WrapB<F> {
fn new() -> WrapB<F> {
WrapB(None)
}
fn set(mut self, f: F) -> Self {
self.0 = Some(f);
self
}
}
trait DoStuff : Sized {
fn handle(self);
}
impl<F, T> DoStuff for WrapA<F>
where F: FnMut(usize, usize) -> T, T: DoStuff {
fn handle(mut self) {
if let Some(ref mut f) = self.0 {
let x = f(1, 2);
let _foo = [0usize; 16];
x.handle();
}
}
}
impl<F> DoStuff for WrapB<F> where F: FnMut(bool) -> usize {
fn handle(mut self) {
if let Some(ref mut f) = self.0 {
println!("{}", f(true));
}
}
}
impl<F, T> WrapA<F>
where F: FnMut(usize, usize) -> T, T: DoStuff {
fn handle_ref(&mut self) {
if let Some(ref mut f) = self.0 {
let x = f(1, 2);
}
}
}
fn main() {
let mut w = WrapA::new().set(|x: usize, y: usize| {
WrapB::new().set(|t: bool| if t { x } else { y }) // (separate errors for `x` vs `y`)
//[ast]~^ ERROR `x` does not live long enough
//[ast]~| ERROR `y` does not live long enough
//[mir]~^^^ ERROR `x` does not live long enough
//[mir]~| ERROR `y` does not live long enough
});
w.handle(); // This works
// w.handle_ref(); // This doesn't
}