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//! This module contains functions with nested borrows in their signatures.
pub fn id_mut_mut<'a, 'b, T>(x: &'a mut &'b mut T) -> &'a mut &'b mut T {
x
}
pub fn id_mut_pair<'a, T>(x: &'a mut (&'a mut T, u32)) -> &'a mut (&'a mut T, u32) {
x
}
pub fn id_mut_pair_test1() {
let mut x: u32 = 0;
let px = &mut x;
let mut p = (px, 1);
let pp0 = &mut p;
let pp1 = id_mut_pair(pp0);
let mut y = 2;
*pp1 = (&mut y, 3);
}
pub fn id_mut_mut_pair<'a, T>(
x: &'a mut &'a mut (&'a mut T, u32),
) -> &'a mut &'a mut (&'a mut T, u32) {
x
}
pub fn id_mut_mut_mut_same<'a, T>(x: &'a mut &'a mut &'a mut u32) -> &'a mut &'a mut &'a mut u32 {
x
}
pub fn id_borrow1<'a, 'b, 'c>(_x: &'a mut &'b u32, _y: &'a &'a mut u32) {
()
}
/// For symbolic execution: testing what happens with several abstractions.
pub fn id_mut_mut_test1() {
let mut x = 0;
let mut px = &mut x;
let ppx = &mut px;
let ppy = id_mut_mut(ppx);
**ppy = 1;
// Ending one abstraction
assert!(*px == 1);
// Ending the other abstraction
assert!(x == 1);
}
/*
/// For symbolic execution: testing what happens with several abstractions.
/// This case is a bit trickier, because we modify the borrow graph through
/// a value returned by a function call.
/// TODO: not supported! We overwrite a borrow in a returned value.
pub fn id_mut_mut_test2() {
let mut x = 0;
let mut px = &mut x;
let ppx = &mut px;
let ppy = id_mut_mut(ppx);
**ppy = 1;
// This time, we replace one of the borrows
let mut y = 2;
let py = &mut y;
*ppy = py;
// Ending one abstraction
assert!(*px == 2);
*px = 3;
// Ending the other abstraction
assert!(x == 1);
assert!(y == 3);
}
*/
/*
/// For symbolic execution: testing what happens with several abstractions.
/// See what happens when chaining function calls.
/// TODO: not supported! We overwrite a borrow in a returned value.
pub fn id_mut_mut_test3() {
let mut x = 0;
let mut px = &mut x;
let ppx = &mut px;
let ppy = id_mut_mut(ppx); // &'a mut &'b mut i32
**ppy = 1;
let ppz = id_mut_mut(ppy); // &'c mut &'b mut i32
**ppz = 2;
// End 'a and 'c
assert!(*px == 2);
// End 'b (2 abstractions at once)
assert!(x == 2);
}*/
/*
/// For symbolic execution: testing what happens with several abstractions.
/// See what happens when chaining function calls.
/// This one is slightly more complex than the previous one.
pub fn id_mut_mut_test4() {
let mut x = 0;
let mut px = &mut x;
let ppx = &mut px;
let ppy = id_mut_mut(ppx); // &'a mut &'b mut i32
**ppy = 1;
let ppz = id_mut_mut(ppy); // &'c mut &'b mut i32
**ppz = 2;
// End 'c
assert!(**ppy == 2);
// End 'a
assert!(*px == 2);
// End 'b (2 abstractions at once)
assert!(x == 2);
}
*/
fn id<'a, T>(x: &'a mut T) -> &'a mut T {
x
}
/// Checking projectors over symbolic values
pub fn test_borrows1() {
let mut x = 3;
let y = id(&mut x);
let z = id(y);
// We do not write a statement which would expand `z` on purpose:
// we want to test that the handling of non-expanded symbolic values
// is correct
assert!(x == 3);
}
fn id_pair<'a, 'b, T>(x: &'a mut T, y: &'b mut T) -> (&'a mut T, &'b mut T) {
(x, y)
}
/// Similar to the previous one
pub fn test_borrows2() {
let mut x = 3;
let mut y = 4;
let z = id_pair(&mut x, &mut y);
// We do not write a statement which would expand `z` on purpose:
// we want to test that the handling of non-expanded symbolic values
// is correct
assert!(x == 3);
assert!(y == 4);
}
/// input type: 'b must last longer than 'a
/// output type: 'a must last longer than 'b
/// So: 'a = 'b, and the function is legal.
pub fn nested_mut_borrows1<'a, 'b>(x: &'a mut &'b mut u32) -> &'b mut &'a mut u32 {
x
}
pub fn nested_shared_borrows1<'a, 'b>(x: &'a &'b u32) -> &'a &'b u32 {
x
}
pub fn nested_borrows1<'a, 'b>(x: &'a mut &'b u32) -> &'a mut &'b u32 {
x
}
pub fn nested_borrows2<'a, 'b>(x: &'a &'b mut u32) -> &'a &'b mut u32 {
x
}
fn nested_borrows1_test1() {
let x = 0;
let mut px = &x;
let ppx = &mut px;
let ppy = nested_borrows1(ppx);
assert!(**ppy == 0);
assert!(x == 0);
}
fn nested_borrows1_test2<'a, 'b>(x: &'a mut &'b u32) -> &'a mut &'b u32 {
nested_borrows1(x)
}
fn nested_borrows2_test1() {
let mut x = 0;
let px = &mut x;
let ppx = &px;
let ppy = nested_borrows2(ppx);
assert!(**ppy == 0);
assert!(x == 0);
}
|
