История изменений

struct A;

struct B<'a> {
    a: &'a A
}

impl A {
    fn make_b(&self) -> B<'_> {
        B { a: self }
    }
}

struct C<'a> {
    a: A,
    b: B<'a>
}

impl<'a> C<'a> {
    fn new() -> Self {
        let a = A {};
        let b = a.make_b();
        Self {
            a,
            b
        }
    }
}

pub fn main() {
    let _c = C::new();
}

  Compiling playground v0.0.1 (/playground)
error[E0515]: cannot return value referencing local variable `a`
  --> src/main.rs:22:9
   |
21 |           let b = a.make_b();
   |                   ---------- `a` is borrowed here
22 | /         Self {
23 | |             a,
24 | |             b
25 | |         }
   | |_________^ returns a value referencing data owned by the current function

error[E0505]: cannot move out of `a` because it is borrowed
  --> src/main.rs:23:13
   |
18 |   impl<'a> C<'a> {
   |        -- lifetime `'a` defined here
19 |       fn new() -> Self {
20 |           let a = A {};
   |               - binding `a` declared here
21 |           let b = a.make_b();
   |                   ---------- borrow of `a` occurs here
22 | /         Self {
23 | |             a,
   | |             ^ move out of `a` occurs here
24 | |             b
25 | |         }
   | |_________- returning this value requires that `a` is borrowed for `'a`

Some errors have detailed explanations: E0505, E0515.
For more information about an error, try `rustc --explain E0505`.
error: could not compile `playground` (bin "playground") due to 2 previous errors

struct A;

struct B<'a> {
    a: &'a A
}

impl A {
    fn make_b(&self) -> B<'_> {
        B { a: self }
    }
}

struct C<'a> {
    a: A,
    b: B<'a>
}

impl<'a> C<'a> {
    fn new() -> Self {
        let a = A {};
        let b = a.make_b();
        Self {
            a,
            b
        }
    }
}

pub fn main() {
    let _c = C::new();
}

  Compiling playground v0.0.1 (/playground)
error[E0515]: cannot return value referencing local variable `a`
  --> src/main.rs:22:9
   |
21 |           let b = a.make_b();
   |                   ---------- `a` is borrowed here
22 | /         Self {
23 | |             a,
24 | |             b
25 | |         }
   | |_________^ returns a value referencing data owned by the current function

error[E0505]: cannot move out of `a` because it is borrowed
  --> src/main.rs:23:13
   |
18 |   impl<'a> C<'a> {
   |        -- lifetime `'a` defined here
19 |       fn new() -> Self {
20 |           let a = A {};
   |               - binding `a` declared here
21 |           let b = a.make_b();
   |                   ---------- borrow of `a` occurs here
22 | /         Self {
23 | |             a,
   | |             ^ move out of `a` occurs here
24 | |             b
25 | |         }
   | |_________- returning this value requires that `a` is borrowed for `'a`

Some errors have detailed explanations: E0505, E0515.
For more information about an error, try `rustc --explain E0505`.
error: could not compile `playground` (bin "playground") due to 2 previous errors