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|
//@ edition: 2024
use std::fmt::Display;
fn display_len<T>(x: &Vec<T>) -> impl Display {
//~^ NOTE in this expansion of desugaring of `impl Trait`
//~| NOTE in this expansion of desugaring of `impl Trait`
//~| NOTE in this expansion of desugaring of `impl Trait`
//~| NOTE in this expansion of desugaring of `impl Trait`
//~| NOTE in this expansion of desugaring of `impl Trait`
x.len()
}
fn conflicting_borrow() {
let mut x = vec![];
let a = display_len(&x);
//~^ NOTE this call may capture more lifetimes than intended
//~| NOTE immutable borrow occurs here
x.push(1);
//~^ ERROR cannot borrow `x` as mutable because it is also borrowed as immutable
//~| NOTE mutable borrow occurs here
println!("{a}");
//~^ NOTE immutable borrow later used here
}
fn needs_static() {
let x = vec![1];
//~^ NOTE binding `x` declared here
let a = display_len(&x);
//~^ ERROR `x` does not live long enough
//~| NOTE this call may capture more lifetimes than intended
//~| NOTE argument requires that `x` is borrowed for `'static`
//~| NOTE borrowed value does not live long enoug
fn needs_static(_: impl Sized + 'static) {}
needs_static(a);
}
//~^ NOTE `x` dropped here while still borrowed
fn is_moved() {
let x = vec![1];
//~^ NOTE binding `x` declared here
let a = display_len(&x);
//~^ NOTE this call may capture more lifetimes than intended
//~| NOTE borrow of `x` occurs here
fn mv(_: impl Sized) {}
mv(x);
//~^ ERROR cannot move out of `x` because it is borrowed
//~| NOTE move out of `x` occurs here
}
//~^ NOTE borrow might be used here, when `a` is dropped
fn display_len_mut<T>(x: &mut Vec<T>) -> impl Display {
//~^ NOTE in this expansion of desugaring of `impl Trait`
//~| NOTE in this expansion of desugaring of `impl Trait`
//~| NOTE in this expansion of desugaring of `impl Trait`
x.len()
}
fn conflicting_borrow_mut() {
let mut x = vec![];
let a = display_len_mut(&mut x);
//~^ NOTE this call may capture more lifetimes than intended
//~| NOTE first mutable borrow occurs here
x.push(1);
//~^ ERROR cannot borrow `x` as mutable more than once
//~| NOTE second mutable borrow occurs here
println!("{a}");
//~^ NOTE first borrow later used here
}
fn needs_static_mut() {
let mut x = vec![1];
//~^ NOTE binding `x` declared here
let a = display_len_mut(&mut x);
//~^ ERROR `x` does not live long enough
//~| NOTE this call may capture more lifetimes than intended
//~| NOTE argument requires that `x` is borrowed for `'static`
//~| NOTE borrowed value does not live long enough
fn needs_static(_: impl Sized + 'static) {}
needs_static(a);
}
//~^ NOTE `x` dropped here while still borrowed
fn is_move_mut() {
let mut x = vec![1];
//~^ NOTE binding `x` declared here
let a = display_len_mut(&mut x);
//~^ NOTE this call may capture more lifetimes than intended
//~| NOTE borrow of `x` occurs here
fn mv(_: impl Sized) {}
mv(x);
//~^ ERROR cannot move out of `x` because it is borrowed
//~| NOTE move out of `x` occurs here
}
//~^ NOTE borrow might be used here, when `a` is dropped
struct S { f: i32 }
fn display_field<T: Copy + Display>(t: &T) -> impl Display {
//~^ NOTE in this expansion of desugaring of `impl Trait`
//~| NOTE in this expansion of desugaring of `impl Trait`
//~| NOTE in this expansion of desugaring of `impl Trait`
*t
}
fn conflicting_borrow_field() {
let mut s = S { f: 0 };
let a = display_field(&s.f);
//~^ NOTE this call may capture more lifetimes than intended
//~| NOTE `s.f` is borrowed here
s.f = 1;
//~^ ERROR cannot assign to `s.f` because it is borrowed
//~| NOTE `s.f` is assigned to here but it was already borrowed
println!("{a}");
//~^ NOTE borrow later used here
}
fn display_field_mut<T: Copy + Display>(t: &mut T) -> impl Display {
*t
}
fn conflicting_borrow_field_mut() {
let mut s = S { f: 0 };
let a = display_field(&mut s.f);
//~^ NOTE this call may capture more lifetimes than intended
//~| NOTE `s.f` is borrowed here
s.f = 1;
//~^ ERROR cannot assign to `s.f` because it is borrowed
//~| NOTE `s.f` is assigned to here but it was already borrowed
println!("{a}");
//~^ NOTE borrow later used here
}
fn field_move() {
let mut s = S { f: 0 };
let a = display_field(&mut s.f);
//~^ NOTE this call may capture more lifetimes than intended
//~| NOTE `s.f` is borrowed here
s.f;
//~^ ERROR cannot use `s.f` because it was mutably borrowed
//~| NOTE use of borrowed `s.f`
println!("{a}");
//~^ NOTE borrow later used here
}
struct Z {
f: Vec<i32>,
}
fn live_long() {
let x;
{
let z = Z { f: vec![1] };
//~^ NOTE binding `z` declared here
x = display_len(&z.f);
//~^ ERROR `z.f` does not live long enough
//~| NOTE this call may capture more lifetimes than intended
//~| NOTE values in a scope are dropped in the opposite order they are defined
//~| NOTE borrowed value does not live long enough
}
//~^ NOTE `z.f` dropped here while still borrowed
}
//~^ NOTE borrow might be used here, when `x` is dropped
fn temp() {
let x = { let x = display_len(&mut vec![0]); x };
//~^ ERROR temporary value dropped while borrowed
//~| NOTE this call may capture more lifetimes than intended
//~| NOTE consider using a `let` binding to create a longer lived value
//~| NOTE borrow later used here
//~| NOTE temporary value is freed at the end of this statement
}
// FIXME: This doesn't display a useful Rust 2024 suggestion :(
fn returned() -> impl Sized {
let x = vec![0];
//~^ NOTE binding `x` declared here
display_len(&x)
//~^ ERROR `x` does not live long enough
//~| NOTE borrowed value does not live long enough
//~| NOTE argument requires that `x` is borrowed for `'static`
}
//~^ NOTE `x` dropped here while still borrowed
fn capture_apit(x: &impl Sized) -> impl Sized {}
//~^ NOTE you could use a `use<...>` bound to explicitly specify captures, but
fn test_apit() {
let x = String::new();
//~^ NOTE binding `x` declared here
let y = capture_apit(&x);
//~^ NOTE borrow of `x` occurs here
//~| NOTE this call may capture more lifetimes than intended
drop(x);
//~^ ERROR cannot move out of `x` because it is borrowed
//~| NOTE move out of `x` occurs here
}
//~^ NOTE borrow might be used here, when `y` is dropped
fn main() {}
|
