error[E0106]: missing lifetime specifier --> $DIR/impl-trait-missing-lifetime-gated.rs:9:54 | LL | fn g(mut x: impl Iterator) -> Option<&()> { x.next() } | ^ expected named lifetime parameter | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static` | LL | fn g(mut x: impl Iterator) -> Option<&'static ()> { x.next() } | +++++++ help: consider introducing a named lifetime parameter | LL | fn g<'a>(mut x: impl Iterator) -> Option<&'a ()> { x.next() } | ++++ ~~~ ~~~ help: alternatively, you might want to return an owned value | LL - fn g(mut x: impl Iterator) -> Option<&()> { x.next() } LL + fn g(mut x: impl Iterator) -> Option<()> { x.next() } | error[E0106]: missing lifetime specifier --> $DIR/impl-trait-missing-lifetime-gated.rs:19:60 | LL | async fn i(mut x: impl Iterator) -> Option<&()> { x.next() } | ^ expected named lifetime parameter | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static` | LL | async fn i(mut x: impl Iterator) -> Option<&'static ()> { x.next() } | +++++++ help: consider introducing a named lifetime parameter | LL | async fn i<'a>(mut x: impl Iterator) -> Option<&'a ()> { x.next() } | ++++ ~~~ ~~~ help: alternatively, you might want to return an owned value | LL - async fn i(mut x: impl Iterator) -> Option<&()> { x.next() } LL + async fn i(mut x: impl Iterator) -> Option<()> { x.next() } | error[E0106]: missing lifetime specifier --> $DIR/impl-trait-missing-lifetime-gated.rs:28:58 | LL | fn g(mut x: impl Iterator) -> Option<&'_ ()> { x.next() } | ^^ expected named lifetime parameter | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values | LL | fn g(mut x: impl Iterator) -> Option<&'static ()> { x.next() } | ~~~~~~~ help: consider introducing a named lifetime parameter | LL | fn g<'a>(mut x: impl Iterator) -> Option<&'a ()> { x.next() } | ++++ ~~~ ~~~ help: alternatively, you might want to return an owned value | LL - fn g(mut x: impl Iterator) -> Option<&'_ ()> { x.next() } LL + fn g(mut x: impl Iterator) -> Option<()> { x.next() } | error[E0106]: missing lifetime specifier --> $DIR/impl-trait-missing-lifetime-gated.rs:38:64 | LL | async fn i(mut x: impl Iterator) -> Option<&'_ ()> { x.next() } | ^^ expected named lifetime parameter | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values | LL | async fn i(mut x: impl Iterator) -> Option<&'static ()> { x.next() } | ~~~~~~~ help: consider introducing a named lifetime parameter | LL | async fn i<'a>(mut x: impl Iterator) -> Option<&'a ()> { x.next() } | ++++ ~~~ ~~~ help: alternatively, you might want to return an owned value | LL - async fn i(mut x: impl Iterator) -> Option<&'_ ()> { x.next() } LL + async fn i(mut x: impl Iterator) -> Option<()> { x.next() } | error[E0106]: missing lifetime specifier --> $DIR/impl-trait-missing-lifetime-gated.rs:49:37 | LL | fn g(mut x: impl Foo) -> Option<&()> { x.next() } | ^ expected named lifetime parameter | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static` | LL | fn g(mut x: impl Foo) -> Option<&'static ()> { x.next() } | +++++++ help: consider introducing a named lifetime parameter | LL | fn g<'a>(mut x: impl Foo) -> Option<&'a ()> { x.next() } | ++++ ~~~ help: alternatively, you might want to return an owned value | LL - fn g(mut x: impl Foo) -> Option<&()> { x.next() } LL + fn g(mut x: impl Foo) -> Option<()> { x.next() } | error[E0106]: missing lifetime specifier --> $DIR/impl-trait-missing-lifetime-gated.rs:60:41 | LL | fn g(mut x: impl Foo<()>) -> Option<&()> { x.next() } | ^ expected named lifetime parameter | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static` | LL | fn g(mut x: impl Foo<()>) -> Option<&'static ()> { x.next() } | +++++++ help: consider introducing a named lifetime parameter | LL | fn g<'a>(mut x: impl Foo<()>) -> Option<&'a ()> { x.next() } | ++++ ~~~ help: alternatively, you might want to return an owned value | LL - fn g(mut x: impl Foo<()>) -> Option<&()> { x.next() } LL + fn g(mut x: impl Foo<()>) -> Option<()> { x.next() } | error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:6:35 | LL | fn f(_: impl Iterator) {} | ^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date help: consider introducing a named lifetime parameter | LL | fn f<'a>(_: impl Iterator) {} | ++++ ++ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:9:39 | LL | fn g(mut x: impl Iterator) -> Option<&()> { x.next() } | ^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date help: consider introducing a named lifetime parameter | LL | fn g<'a>(mut x: impl Iterator) -> Option<&()> { x.next() } | ++++ ++ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:25:35 | LL | fn f(_: impl Iterator) {} | ^^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date help: consider introducing a named lifetime parameter | LL | fn f<'a>(_: impl Iterator) {} | ++++ ~~ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:28:39 | LL | fn g(mut x: impl Iterator) -> Option<&'_ ()> { x.next() } | ^^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date help: consider introducing a named lifetime parameter | LL | fn g<'a>(mut x: impl Iterator) -> Option<&'_ ()> { x.next() } | ++++ ~~ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:46:18 | LL | fn f(_: impl Foo) {} | ^^^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date help: consider introducing a named lifetime parameter | LL | fn f<'a>(_: impl Foo<'a>) {} | ++++ ++++ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:49:22 | LL | fn g(mut x: impl Foo) -> Option<&()> { x.next() } | ^^^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date help: consider introducing a named lifetime parameter | LL | fn g<'a>(mut x: impl Foo<'a>) -> Option<&()> { x.next() } | ++++ ++++ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:57:22 | LL | fn f(_: impl Foo<()>) {} | ^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date help: consider introducing a named lifetime parameter | LL | fn f<'a>(_: impl Foo<'a, ()>) {} | ++++ +++ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:60:26 | LL | fn g(mut x: impl Foo<()>) -> Option<&()> { x.next() } | ^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date help: consider introducing a named lifetime parameter | LL | fn g<'a>(mut x: impl Foo<'a, ()>) -> Option<&()> { x.next() } | ++++ +++ error: lifetime may not live long enough --> $DIR/impl-trait-missing-lifetime-gated.rs:19:67 | LL | async fn i(mut x: impl Iterator) -> Option<&()> { x.next() } | ----------------------------------------------------------- ^^^^^^^^ returning this value requires that `'1` must outlive `'static` | | | return type `impl Future>` contains a lifetime `'1` error: lifetime may not live long enough --> $DIR/impl-trait-missing-lifetime-gated.rs:38:73 | LL | async fn i(mut x: impl Iterator) -> Option<&'_ ()> { x.next() } | ----------------------------------------------------------------- ^^^^^^^^ returning this value requires that `'1` must outlive `'static` | | | return type `impl Future>` contains a lifetime `'1` error: aborting due to 16 previous errors Some errors have detailed explanations: E0106, E0658. For more information about an error, try `rustc --explain E0106`.