| // Copyright 2014 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. |
| |
| // Test how overloaded deref interacts with borrows when DerefMut |
| // is implemented. |
| |
| use std::ops::{Deref, DerefMut}; |
| |
| struct Own<T> { |
| value: *mut T |
| } |
| |
| impl<T> Deref for Own<T> { |
| type Target = T; |
| |
| fn deref(&self) -> &T { |
| unsafe { &*self.value } |
| } |
| } |
| |
| impl<T> DerefMut for Own<T> { |
| fn deref_mut(&mut self) -> &mut T { |
| unsafe { &mut *self.value } |
| } |
| } |
| |
| struct Point { |
| x: isize, |
| y: isize |
| } |
| |
| impl Point { |
| fn get(&self) -> (isize, isize) { |
| (self.x, self.y) |
| } |
| |
| fn set(&mut self, x: isize, y: isize) { |
| self.x = x; |
| self.y = y; |
| } |
| |
| fn x_ref(&self) -> &isize { |
| &self.x |
| } |
| |
| fn y_mut(&mut self) -> &mut isize { |
| &mut self.y |
| } |
| } |
| |
| fn deref_imm_field(x: Own<Point>) { |
| let __isize = &x.y; |
| } |
| |
| fn deref_mut_field1(x: Own<Point>) { |
| let __isize = &mut x.y; //~ ERROR cannot borrow |
| } |
| |
| fn deref_mut_field2(mut x: Own<Point>) { |
| let __isize = &mut x.y; |
| } |
| |
| fn deref_extend_field(x: &Own<Point>) -> &isize { |
| &x.y |
| } |
| |
| fn deref_extend_mut_field1(x: &Own<Point>) -> &mut isize { |
| &mut x.y //~ ERROR cannot borrow |
| } |
| |
| fn deref_extend_mut_field2(x: &mut Own<Point>) -> &mut isize { |
| &mut x.y |
| } |
| |
| fn deref_extend_mut_field3(x: &mut Own<Point>) { |
| // Hmm, this is unfortunate, because with box it would work, |
| // but it's presently the expected outcome. See `deref_extend_mut_field4` |
| // for the workaround. |
| |
| let _x = &mut x.x; |
| let _y = &mut x.y; //~ ERROR cannot borrow |
| } |
| |
| fn deref_extend_mut_field4<'a>(x: &'a mut Own<Point>) { |
| let p = &mut **x; |
| let _x = &mut p.x; |
| let _y = &mut p.y; |
| } |
| |
| fn assign_field1<'a>(x: Own<Point>) { |
| x.y = 3; //~ ERROR cannot borrow |
| } |
| |
| fn assign_field2<'a>(x: &'a Own<Point>) { |
| x.y = 3; //~ ERROR cannot borrow |
| } |
| |
| fn assign_field3<'a>(x: &'a mut Own<Point>) { |
| x.y = 3; |
| } |
| |
| fn assign_field4<'a>(x: &'a mut Own<Point>) { |
| let _p: &mut Point = &mut **x; |
| x.y = 3; //~ ERROR cannot borrow |
| } |
| |
| fn deref_imm_method(x: Own<Point>) { |
| let __isize = x.get(); |
| } |
| |
| fn deref_mut_method1(x: Own<Point>) { |
| x.set(0, 0); //~ ERROR cannot borrow |
| } |
| |
| fn deref_mut_method2(mut x: Own<Point>) { |
| x.set(0, 0); |
| } |
| |
| fn deref_extend_method(x: &Own<Point>) -> &isize { |
| x.x_ref() |
| } |
| |
| fn deref_extend_mut_method1(x: &Own<Point>) -> &mut isize { |
| x.y_mut() //~ ERROR cannot borrow |
| } |
| |
| fn deref_extend_mut_method2(x: &mut Own<Point>) -> &mut isize { |
| x.y_mut() |
| } |
| |
| fn assign_method1<'a>(x: Own<Point>) { |
| *x.y_mut() = 3; //~ ERROR cannot borrow |
| } |
| |
| fn assign_method2<'a>(x: &'a Own<Point>) { |
| *x.y_mut() = 3; //~ ERROR cannot borrow |
| } |
| |
| fn assign_method3<'a>(x: &'a mut Own<Point>) { |
| *x.y_mut() = 3; |
| } |
| |
| pub fn main() {} |