diff options
Diffstat (limited to '')
-rw-r--r-- | src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.rs | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.rs b/src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.rs new file mode 100644 index 000000000..76a1d12ea --- /dev/null +++ b/src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.rs @@ -0,0 +1,142 @@ +// 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 + use_mut(_x); +} +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 + use_mut(_p); +} +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() {} + +fn use_mut<T>(_: &mut T) {} |