// 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 or the MIT license // , 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 { value: *mut T } impl Deref for Own { fn deref<'a>(&'a self) -> &'a T { unsafe { &*self.value } } } impl DerefMut for Own { fn deref_mut<'a>(&'a mut self) -> &'a mut T { unsafe { &mut *self.value } } } struct Point { x: int, y: int } impl Point { fn get(&self) -> (int, int) { (self.x, self.y) } fn set(&mut self, x: int, y: int) { self.x = x; self.y = y; } fn x_ref<'a>(&'a self) -> &'a int { &self.x } fn y_mut<'a>(&'a mut self) -> &'a mut int { &mut self.y } } fn deref_imm_field(x: Own) { let _i = &x.y; } fn deref_mut_field1(x: Own) { let _i = &mut x.y; //~ ERROR cannot borrow } fn deref_mut_field2(mut x: Own) { let _i = &mut x.y; } fn deref_extend_field<'a>(x: &'a Own) -> &'a int { &x.y } fn deref_extend_mut_field1<'a>(x: &'a Own) -> &'a mut int { &mut x.y //~ ERROR cannot borrow } fn deref_extend_mut_field2<'a>(x: &'a mut Own) -> &'a mut int { &mut x.y } fn deref_extend_mut_field3<'a>(x: &'a mut Own) { // Hmm, this is unfortunate, because with ~ 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) { let p = &mut **x; let _x = &mut p.x; let _y = &mut p.y; } fn assign_field1<'a>(x: Own) { x.y = 3; //~ ERROR cannot borrow } fn assign_field2<'a>(x: &'a Own) { x.y = 3; //~ ERROR cannot assign } fn assign_field3<'a>(x: &'a mut Own) { x.y = 3; } fn assign_field4<'a>(x: &'a mut Own) { let _p: &mut Point = &mut **x; x.y = 3; //~ ERROR cannot borrow } // FIXME(eddyb) #12825 This shouldn't attempt to call deref_mut. /* fn deref_imm_method(x: Own) { let _i = x.get(); } */ fn deref_mut_method1(x: Own) { x.set(0, 0); //~ ERROR cannot borrow } fn deref_mut_method2(mut x: Own) { x.set(0, 0); } fn deref_extend_method<'a>(x: &'a Own) -> &'a int { x.x_ref() } fn deref_extend_mut_method1<'a>(x: &'a Own) -> &'a mut int { x.y_mut() //~ ERROR cannot borrow } fn deref_extend_mut_method2<'a>(x: &'a mut Own) -> &'a mut int { x.y_mut() } fn assign_method1<'a>(x: Own) { *x.y_mut() = 3; //~ ERROR cannot borrow } fn assign_method2<'a>(x: &'a Own) { *x.y_mut() = 3; //~ ERROR cannot borrow } fn assign_method3<'a>(x: &'a mut Own) { *x.y_mut() = 3; } pub fn main() {}