src/test/ui/suggestions/expected-boxed-future-isnt-pinned.stderr

   1 error[E0308]: mismatched types
   2   --> $DIR/expected-boxed-future-isnt-pinned.rs:11:5
   3    |
   4 LL | fn foo<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
   5    |        - this type parameter                            ----------------------- expected `Pin<Box<(dyn Future<Output = i32> + Send + 'static)>>` because of return type
   6 LL |     // We could instead use an `async` block, but this way we have no std spans.
   7 LL |     x
   8    |     ^
   9    |     |
  10    |     expected struct `Pin`, found type parameter `F`
  11    |     help: you need to pin and box this expression: `Box::pin(x)`
  12    |
  13    = note:      expected struct `Pin<Box<(dyn Future<Output = i32> + Send + 'static)>>`
  14            found type parameter `F`
  15
  16 error[E0308]: mismatched types
  17   --> $DIR/expected-boxed-future-isnt-pinned.rs:18:5
  18    |
  19 LL | fn bar<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
  20    |                                                         ----------------------- expected `Pin<Box<(dyn Future<Output = i32> + Send + 'static)>>` because of return type
  21 LL |     Box::new(x)
  22    |     ^^^^^^^^^^^ expected struct `Pin`, found struct `Box`
  23    |
  24    = note: expected struct `Pin<Box<(dyn Future<Output = i32> + Send + 'static)>>`
  25               found struct `Box<F>`
  26    = help: use `Box::pin`
  27
  28 error[E0308]: mismatched types
  29   --> $DIR/expected-boxed-future-isnt-pinned.rs:22:14
  30    |
  31 LL | fn baz<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
  32    |        - this type parameter
  33 LL |     Pin::new(x)
  34    |              ^
  35    |              |
  36    |              expected struct `Box`, found type parameter `F`
  37    |              help: store this in the heap by calling `Box::new`: `Box::new(x)`
  38    |
  39    = note:      expected struct `Box<dyn Future<Output = i32> + Send>`
  40            found type parameter `F`
  41    = note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
  42
  43 error[E0277]: `dyn Future<Output = i32> + Send` cannot be unpinned
  44   --> $DIR/expected-boxed-future-isnt-pinned.rs:22:5
  45    |
  46 LL |     Pin::new(x)
  47    |     ^^^^^^^^ the trait `Unpin` is not implemented for `dyn Future<Output = i32> + Send`
  48    |
  49    = note: consider using `Box::pin`
  50    = note: required by `Pin::<P>::new`
  51
  52 error[E0277]: `dyn Future<Output = i32> + Send` cannot be unpinned
  53   --> $DIR/expected-boxed-future-isnt-pinned.rs:27:5
  54    |
  55 LL |     Pin::new(Box::new(x))
  56    |     ^^^^^^^^ the trait `Unpin` is not implemented for `dyn Future<Output = i32> + Send`
  57    |
  58    = note: consider using `Box::pin`
  59    = note: required by `Pin::<P>::new`
  60
  61 error[E0308]: mismatched types
  62   --> $DIR/expected-boxed-future-isnt-pinned.rs:31:5
  63    |
  64 LL |   fn zap() -> BoxFuture<'static, i32> {
  65    |               ----------------------- expected `Pin<Box<(dyn Future<Output = i32> + Send + 'static)>>` because of return type
  66 LL | /     async {
  67 LL | |         42
  68 LL | |     }
  69    | |_____^ expected struct `Pin`, found opaque type
  70    |
  71   ::: $SRC_DIR/core/src/future/mod.rs:LL:COL
  72    |
  73 LL |   pub const fn from_generator<T>(gen: T) -> impl Future<Output = T::Return>
  74    |                                             ------------------------------- the found opaque type
  75    |
  76    = note:   expected struct `Pin<Box<(dyn Future<Output = i32> + Send + 'static)>>`
  77            found opaque type `impl Future`
  78 help: you need to pin and box this expression
  79    |
  80 LL |     Box::pin(async {
  81 LL |         42
  82 LL |     })
  83    |
  84
  85 error: aborting due to 6 previous errors
  86
  87 Some errors have detailed explanations: E0277, E0308.
  88 For more information about an error, try `rustc --explain E0277`.