error: lifetime may not live long enough --> $DIR/issue-79187-2.rs:9:24 | LL | take_foo(|a: &i32| a); | - - ^ returning this value requires that `'1` must outlive `'2` | | | | | return type of closure is &'2 i32 | let's call the lifetime of this reference `'1` error: lifetime may not live long enough --> $DIR/issue-79187-2.rs:10:34 | LL | take_foo(|a: &i32| -> &i32 { a }); | - - ^ returning this value requires that `'1` must outlive `'2` | | | | | let's call the lifetime of this reference `'2` | let's call the lifetime of this reference `'1` error: implementation of `FnOnce` is not general enough --> $DIR/issue-79187-2.rs:8:5 | LL | take_foo(|a| a); | ^^^^^^^^^^^^^^^ implementation of `FnOnce` is not general enough | = note: closure with signature `fn(&'2 i32) -> &i32` must implement `FnOnce<(&'1 i32,)>`, for any lifetime `'1`... = note: ...but it actually implements `FnOnce<(&'2 i32,)>`, for some specific lifetime `'2` error[E0308]: mismatched types --> $DIR/issue-79187-2.rs:8:5 | LL | take_foo(|a| a); | ^^^^^^^^^^^^^^^ one type is more general than the other | = note: expected type `for<'r> Fn<(&'r i32,)>` found type `Fn<(&i32,)>` note: this closure does not fulfill the lifetime requirements --> $DIR/issue-79187-2.rs:8:14 | LL | take_foo(|a| a); | ^^^^^ note: the lifetime requirement is introduced here --> $DIR/issue-79187-2.rs:5:21 | LL | fn take_foo(_: impl Foo) {} | ^^^ error[E0308]: mismatched types --> $DIR/issue-79187-2.rs:9:5 | LL | take_foo(|a: &i32| a); | ^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other | = note: expected reference `&i32` found reference `&i32` note: the lifetime requirement is introduced here --> $DIR/issue-79187-2.rs:5:21 | LL | fn take_foo(_: impl Foo) {} | ^^^ error[E0308]: mismatched types --> $DIR/issue-79187-2.rs:10:5 | LL | take_foo(|a: &i32| -> &i32 { a }); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other | = note: expected reference `&i32` found reference `&i32` note: the lifetime requirement is introduced here --> $DIR/issue-79187-2.rs:5:21 | LL | fn take_foo(_: impl Foo) {} | ^^^ error: aborting due to 6 previous errors For more information about this error, try `rustc --explain E0308`.