rust/tests/ui/binding/issue-53114-safety-checks.rs
2023-01-11 09:32:08 +00:00

52 lines
1.6 KiB
Rust

// Issue #53114: NLL's borrow check had some deviations from the old borrow
// checker, and both had some deviations from our ideal state. This test
// captures the behavior of how `_` bindings are handled with respect to how we
// flag expressions that are meant to request unsafe blocks.
#[derive(Copy, Clone)]
struct I(i64);
#[derive(Copy, Clone)]
struct F(f64);
union U { a: I, b: F }
#[repr(packed)]
struct P {
a: &'static i8,
b: &'static u32,
}
fn let_wild_gets_unsafe_field() {
let u1 = U { a: I(0) };
let u2 = U { a: I(1) };
let p = P { a: &2, b: &3 };
let _ = &p.b; //~ ERROR reference to packed field
//~^ WARN will become a hard error
let _ = u1.a; // #53114: should eventually signal error as well
let _ = &u2.a; //~ ERROR [E0133]
// variation on above with `_` in substructure
let (_,) = (&p.b,); //~ ERROR reference to packed field
//~^ WARN will become a hard error
let (_,) = (u1.a,); //~ ERROR [E0133]
let (_,) = (&u2.a,); //~ ERROR [E0133]
}
fn match_unsafe_field_to_wild() {
let u1 = U { a: I(0) };
let u2 = U { a: I(1) };
let p = P { a: &2, b: &3 };
match &p.b { _ => { } } //~ ERROR reference to packed field
//~^ WARN will become a hard error
match u1.a { _ => { } } //~ ERROR [E0133]
match &u2.a { _ => { } } //~ ERROR [E0133]
// variation on above with `_` in substructure
match (&p.b,) { (_,) => { } } //~ ERROR reference to packed field
//~^ WARN will become a hard error
match (u1.a,) { (_,) => { } } //~ ERROR [E0133]
match (&u2.a,) { (_,) => { } } //~ ERROR [E0133]
}
fn main() { }