error[E0261]: use of undeclared lifetime name `'b` --> $DIR/nested-rpit-hrtb.rs:56:77 | LL | fn two_htrb_outlives() -> impl for<'a> Foo<'a, Assoc = impl for<'b> Sized + 'b> {} | ^^ undeclared lifetime | = note: for more information on higher-ranked polymorphism, visit https://doc.rust-lang.org/nomicon/hrtb.html help: consider making the bound lifetime-generic with a new `'b` lifetime | LL | fn two_htrb_outlives() -> impl for<'b, 'a> Foo<'a, Assoc = impl for<'b> Sized + 'b> {} | +++ help: consider introducing lifetime `'b` here | LL | fn two_htrb_outlives<'b>() -> impl for<'a> Foo<'a, Assoc = impl for<'b> Sized + 'b> {} | ++++ error[E0261]: use of undeclared lifetime name `'b` --> $DIR/nested-rpit-hrtb.rs:64:82 | LL | fn two_htrb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl for<'b> Sized + 'b> {} | ^^ undeclared lifetime | help: consider making the bound lifetime-generic with a new `'b` lifetime | LL | fn two_htrb_outlives_uses() -> impl for<'b, 'a> Bar<'a, Assoc = impl for<'b> Sized + 'b> {} | +++ help: consider introducing lifetime `'b` here | LL | fn two_htrb_outlives_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl for<'b> Sized + 'b> {} | ++++ error[E0657]: `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait` --> $DIR/nested-rpit-hrtb.rs:25:69 | LL | fn one_hrtb_outlives() -> impl for<'a> Foo<'a, Assoc = impl Sized + 'a> {} | ^^ | note: lifetime declared here --> $DIR/nested-rpit-hrtb.rs:25:36 | LL | fn one_hrtb_outlives() -> impl for<'a> Foo<'a, Assoc = impl Sized + 'a> {} | ^^ error[E0657]: `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait` --> $DIR/nested-rpit-hrtb.rs:29:68 | LL | fn one_hrtb_trait_param() -> impl for<'a> Foo<'a, Assoc = impl Qux<'a>> {} | ^^ | note: lifetime declared here --> $DIR/nested-rpit-hrtb.rs:29:39 | LL | fn one_hrtb_trait_param() -> impl for<'a> Foo<'a, Assoc = impl Qux<'a>> {} | ^^ error[E0657]: `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait` --> $DIR/nested-rpit-hrtb.rs:32:74 | LL | fn one_hrtb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'a> {} | ^^ | note: lifetime declared here --> $DIR/nested-rpit-hrtb.rs:32:41 | LL | fn one_hrtb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'a> {} | ^^ error[E0657]: `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait` --> $DIR/nested-rpit-hrtb.rs:35:73 | LL | fn one_hrtb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl Qux<'a>> {} | ^^ | note: lifetime declared here --> $DIR/nested-rpit-hrtb.rs:35:44 | LL | fn one_hrtb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl Qux<'a>> {} | ^^ error[E0277]: the trait bound `for<'a> &'a (): Qux<'b>` is not satisfied --> $DIR/nested-rpit-hrtb.rs:45:79 | LL | fn one_hrtb_mention_fn_trait_param_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl Qux<'b>> {} | ^^^^^^^^^^^^ the trait `for<'a> Qux<'b>` is not implemented for `&'a ()` | = help: the trait `Qux<'_>` is implemented for `()` = help: for that trait implementation, expected `()`, found `&'a ()` error: implementation of `Bar` is not general enough --> $DIR/nested-rpit-hrtb.rs:49:93 | LL | fn one_hrtb_mention_fn_outlives_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'b> {} | ^^ implementation of `Bar` is not general enough | = note: `()` must implement `Bar<'a>` = note: ...but it actually implements `Bar<'0>`, for some specific lifetime `'0` error[E0277]: the trait bound `for<'a, 'b> &'a (): Qux<'b>` is not satisfied --> $DIR/nested-rpit-hrtb.rs:60:64 | LL | fn two_htrb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl for<'b> Qux<'b>> {} | ^^^^^^^^^^^^^^^^^^^^ the trait `for<'a, 'b> Qux<'b>` is not implemented for `&'a ()` | = help: the trait `Qux<'_>` is implemented for `()` = help: for that trait implementation, expected `()`, found `&'a ()` error: aborting due to 9 previous errors Some errors have detailed explanations: E0261, E0277, E0657. For more information about an error, try `rustc --explain E0261`.