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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/closures/2229_closure_analysis/run_pass/mut_ref.rs | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/src/test/ui/closures/2229_closure_analysis/run_pass/mut_ref.rs b/src/test/ui/closures/2229_closure_analysis/run_pass/mut_ref.rs new file mode 100644 index 000000000..9f0c4d96a --- /dev/null +++ b/src/test/ui/closures/2229_closure_analysis/run_pass/mut_ref.rs @@ -0,0 +1,54 @@ +// edition:2021 +// run-pass + +// Test that we can mutate a place through a mut-borrow +// that is captured by the closure + +// Check that we can mutate when one deref is required +fn mut_ref_1() { + let mut x = String::new(); + let rx = &mut x; + + let mut c = || { + *rx = String::new(); + }; + + c(); +} + +// Similar example as mut_ref_1, we don't deref the imm-borrow here, +// and so we are allowed to mutate. +fn mut_ref_2() { + let x = String::new(); + let y = String::new(); + let mut ref_x = &x; + let m_ref_x = &mut ref_x; + + let mut c = || { + *m_ref_x = &y; + }; + + c(); +} + +// Check that we can mutate when multiple derefs of mut-borrows are required to reach +// the target place. +// It works because all derefs are mutable, if either of them was an immutable +// borrow, then we would not be able to deref. +fn mut_mut_ref() { + let mut x = String::new(); + let mut mref_x = &mut x; + let m_mref_x = &mut mref_x; + + let mut c = || { + **m_mref_x = String::new(); + }; + + c(); +} + +fn main() { + mut_ref_1(); + mut_ref_2(); + mut_mut_ref(); +} |