error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds --> $DIR/must_outlive_least_region_or_bound.rs:7:35 | LL | fn elided(x: &i32) -> impl Copy { x } | ---- ^ | | | hidden type `&i32` captures the anonymous lifetime defined here | help: to declare that the `impl Trait` captures `'_`, you can add an explicit `'_` lifetime bound | LL | fn elided(x: &i32) -> impl Copy + '_ { x } | ++++ error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds --> $DIR/must_outlive_least_region_or_bound.rs:10:44 | LL | fn explicit<'a>(x: &'a i32) -> impl Copy { x } | -- ^ | | | hidden type `&'a i32` captures the lifetime `'a` as defined here | help: to declare that the `impl Trait` captures `'a`, you can add an explicit `'a` lifetime bound | LL | fn explicit<'a>(x: &'a i32) -> impl Copy + 'a { x } | ++++ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement --> $DIR/must_outlive_least_region_or_bound.rs:13:46 | LL | fn elided2(x: &i32) -> impl Copy + 'static { x } | ---- ^ ...is used here... | | | this data with an anonymous lifetime `'_`... | note: ...and is required to live as long as `'static` here --> $DIR/must_outlive_least_region_or_bound.rs:13:24 | LL | fn elided2(x: &i32) -> impl Copy + 'static { x } | ^^^^^^^^^^^^^^^^^^^ help: consider changing the `impl Trait`'s explicit `'static` bound to the lifetime of argument `x` | LL | fn elided2(x: &i32) -> impl Copy + '_ { x } | ~~ help: alternatively, add an explicit `'static` bound to this reference | LL | fn elided2(x: &'static i32) -> impl Copy + 'static { x } | ~~~~~~~~~~~~ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement --> $DIR/must_outlive_least_region_or_bound.rs:17:55 | LL | fn explicit2<'a>(x: &'a i32) -> impl Copy + 'static { x } | ------- ^ ...is used here... | | | this data with lifetime `'a`... | note: ...and is required to live as long as `'static` here --> $DIR/must_outlive_least_region_or_bound.rs:17:33 | LL | fn explicit2<'a>(x: &'a i32) -> impl Copy + 'static { x } | ^^^^^^^^^^^^^^^^^^^ help: consider changing the `impl Trait`'s explicit `'static` bound to the lifetime of argument `x` | LL | fn explicit2<'a>(x: &'a i32) -> impl Copy + 'a { x } | ~~ help: alternatively, add an explicit `'static` bound to this reference | LL | fn explicit2<'a>(x: &'static i32) -> impl Copy + 'static { x } | ~~~~~~~~~~~~ error[E0621]: explicit lifetime required in the type of `x` --> $DIR/must_outlive_least_region_or_bound.rs:21:24 | LL | fn foo<'a>(x: &i32) -> impl Copy + 'a { x } | ---- ^^^^^^^^^^^^^^ lifetime `'a` required | | | help: add explicit lifetime `'a` to the type of `x`: `&'a i32` error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement --> $DIR/must_outlive_least_region_or_bound.rs:36:65 | LL | fn elided5(x: &i32) -> (Box, impl Debug) { (Box::new(x), x) } | ---- this data with an anonymous lifetime `'_`... ^ ...is used and required to live as long as `'static` here | help: to declare that the trait object captures data from argument `x`, you can add an explicit `'_` lifetime bound | LL | fn elided5(x: &i32) -> (Box, impl Debug) { (Box::new(x), x) } | ++++ help: to declare that the `impl Trait` captures data from argument `x`, you can add an explicit `'_` lifetime bound | LL | fn elided5(x: &i32) -> (Box, impl Debug + '_) { (Box::new(x), x) } | ++++ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement --> $DIR/must_outlive_least_region_or_bound.rs:43:69 | LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'static { x } | ------- this data with lifetime `'a`... ^ ...is used here... | note: ...and is required to live as long as `'static` here --> $DIR/must_outlive_least_region_or_bound.rs:43:34 | LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'static { x } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing the `impl Trait`'s explicit `'static` bound to the lifetime of argument `x` | LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'a { x } | ~~ help: alternatively, add an explicit `'static` bound to this reference | LL | fn with_bound<'a>(x: &'static i32) -> impl LifetimeTrait<'a> + 'static { x } | ~~~~~~~~~~~~ error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds --> $DIR/must_outlive_least_region_or_bound.rs:50:5 | LL | fn move_lifetime_into_fn<'a, 'b>(x: &'a u32, y: &'b u32) -> impl Fn(&'a u32) { | -- hidden type `[closure@$DIR/must_outlive_least_region_or_bound.rs:50:5: 50:31]` captures the lifetime `'b` as defined here LL | move |_| println!("{}", y) | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | help: to declare that the `impl Trait` captures `'b`, you can add an explicit `'b` lifetime bound | LL | fn move_lifetime_into_fn<'a, 'b>(x: &'a u32, y: &'b u32) -> impl Fn(&'a u32) + 'b { | ++++ error[E0310]: the parameter type `T` may not live long enough --> $DIR/must_outlive_least_region_or_bound.rs:54:51 | LL | fn ty_param_wont_outlive_static(x: T) -> impl Debug + 'static { | ^^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds | help: consider adding an explicit lifetime bound... | LL | fn ty_param_wont_outlive_static(x: T) -> impl Debug + 'static { | +++++++++ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement --> $DIR/must_outlive_least_region_or_bound.rs:24:50 | LL | fn elided3(x: &i32) -> Box { Box::new(x) } | ---- ^ ...is used and required to live as long as `'static` here | | | this data with an anonymous lifetime `'_`... | note: `'static` lifetime requirement introduced by the return type --> $DIR/must_outlive_least_region_or_bound.rs:24:28 | LL | fn elided3(x: &i32) -> Box { Box::new(x) } | ^^^^^^^^^ ----------- because of this returned expression | | | `'static` requirement introduced here help: to declare that the trait object captures data from argument `x`, you can add an explicit `'_` lifetime bound | LL | fn elided3(x: &i32) -> Box { Box::new(x) } | ++++ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement --> $DIR/must_outlive_least_region_or_bound.rs:27:59 | LL | fn explicit3<'a>(x: &'a i32) -> Box { Box::new(x) } | ------- ^ ...is used and required to live as long as `'static` here | | | this data with lifetime `'a`... | note: `'static` lifetime requirement introduced by the return type --> $DIR/must_outlive_least_region_or_bound.rs:27:37 | LL | fn explicit3<'a>(x: &'a i32) -> Box { Box::new(x) } | ^^^^^^^^^ ----------- because of this returned expression | | | `'static` requirement introduced here help: to declare that the trait object captures data from argument `x`, you can add an explicit `'a` lifetime bound | LL | fn explicit3<'a>(x: &'a i32) -> Box { Box::new(x) } | ++++ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement --> $DIR/must_outlive_least_region_or_bound.rs:30:60 | LL | fn elided4(x: &i32) -> Box { Box::new(x) } | ---- ^ ...is used and required to live as long as `'static` here | | | this data with an anonymous lifetime `'_`... | note: `'static` lifetime requirement introduced by the return type --> $DIR/must_outlive_least_region_or_bound.rs:30:40 | LL | fn elided4(x: &i32) -> Box { Box::new(x) } | ^^^^^^^ ----------- because of this returned expression | | | `'static` requirement introduced here help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `x` | LL | fn elided4(x: &i32) -> Box { Box::new(x) } | ~~ help: alternatively, add an explicit `'static` bound to this reference | LL | fn elided4(x: &'static i32) -> Box { Box::new(x) } | ~~~~~~~~~~~~ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement --> $DIR/must_outlive_least_region_or_bound.rs:33:69 | LL | fn explicit4<'a>(x: &'a i32) -> Box { Box::new(x) } | ------- this data with lifetime `'a`... ^ ...is used and required to live as long as `'static` here | note: `'static` lifetime requirement introduced by the return type --> $DIR/must_outlive_least_region_or_bound.rs:33:49 | LL | fn explicit4<'a>(x: &'a i32) -> Box { Box::new(x) } | ^^^^^^^ ----------- because of this returned expression | | | `'static` requirement introduced here help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `x` | LL | fn explicit4<'a>(x: &'a i32) -> Box { Box::new(x) } | ~~ help: alternatively, add an explicit `'static` bound to this reference | LL | fn explicit4<'a>(x: &'static i32) -> Box { Box::new(x) } | ~~~~~~~~~~~~ error: aborting due to 13 previous errors Some errors have detailed explanations: E0310, E0621, E0700, E0759. For more information about an error, try `rustc --explain E0310`.