File: E0746.stderr

package info (click to toggle)
rustc-web 1.78.0%2Bdfsg1-2~deb11u3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 1,245,360 kB
  • sloc: xml: 147,985; javascript: 18,022; sh: 11,083; python: 10,265; ansic: 6,172; cpp: 5,023; asm: 4,390; makefile: 4,269
file content (37 lines) | stat: -rw-r--r-- 1,219 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
error[E0746]: return type cannot have an unboxed trait object
  --> $DIR/E0746.rs:8:13
   |
LL | fn foo() -> dyn Trait { Struct }
   |             ^^^^^^^^^ doesn't have a size known at compile-time
   |
help: return an `impl Trait` instead of a `dyn Trait`, if all returned values are the same type
   |
LL | fn foo() -> impl Trait { Struct }
   |             ~~~~
help: box the return type, and wrap all of the returned values in `Box::new`
   |
LL | fn foo() -> Box<dyn Trait> { Box::new(Struct) }
   |             ++++         +   +++++++++      +

error[E0746]: return type cannot have an unboxed trait object
  --> $DIR/E0746.rs:11:13
   |
LL | fn bar() -> dyn Trait {
   |             ^^^^^^^^^ doesn't have a size known at compile-time
   |
help: return an `impl Trait` instead of a `dyn Trait`, if all returned values are the same type
   |
LL | fn bar() -> impl Trait {
   |             ~~~~
help: box the return type, and wrap all of the returned values in `Box::new`
   |
LL ~ fn bar() -> Box<dyn Trait> {
LL |     if true {
LL ~         return Box::new(0);
LL |     }
LL ~     Box::new(42)
   |

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0746`.