From 6145918c83d10e9679805b8feff0286ce9e58afc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Wed, 3 Jun 2020 11:34:04 -0700 Subject: [PATCH] Change E0758 to E0759 to avoid conflict with #72912 --- src/librustc_error_codes/error_codes.rs | 1 + src/librustc_error_codes/error_codes/E0759.md | 67 +++++++++++++++++++ .../nice_region_error/static_impl_trait.rs | 2 +- .../ui/async-await/issues/issue-62097.stderr | 4 +- .../must_outlive_least_region_or_bound.stderr | 20 +++--- .../static-return-lifetime-infered.stderr | 6 +- src/test/ui/issues/issue-16922.stderr | 4 +- ...ect-lifetime-default-from-box-error.stderr | 4 +- .../region-object-lifetime-in-coercion.stderr | 8 +-- .../regions-close-object-into-object-2.stderr | 4 +- .../regions-close-object-into-object-4.stderr | 4 +- .../regions/regions-proc-bound-capture.stderr | 4 +- ...types_pin_lifetime_impl_trait-async.stderr | 4 +- ..._self_types_pin_lifetime_impl_trait.stderr | 4 +- .../missing-lifetimes-in-signature.stderr | 4 +- .../dyn-trait-underscore.stderr | 4 +- 16 files changed, 106 insertions(+), 38 deletions(-) create mode 100644 src/librustc_error_codes/error_codes/E0759.md diff --git a/src/librustc_error_codes/error_codes.rs b/src/librustc_error_codes/error_codes.rs index 760b4d7ba00a3..2e3ba13f37911 100644 --- a/src/librustc_error_codes/error_codes.rs +++ b/src/librustc_error_codes/error_codes.rs @@ -438,6 +438,7 @@ E0752: include_str!("./error_codes/E0752.md"), E0753: include_str!("./error_codes/E0753.md"), E0754: include_str!("./error_codes/E0754.md"), E0758: include_str!("./error_codes/E0758.md"), +E0759: include_str!("./error_codes/E0759.md"), E0760: include_str!("./error_codes/E0760.md"), ; // E0006, // merged with E0005 diff --git a/src/librustc_error_codes/error_codes/E0759.md b/src/librustc_error_codes/error_codes/E0759.md new file mode 100644 index 0000000000000..a74759bdf634b --- /dev/null +++ b/src/librustc_error_codes/error_codes/E0759.md @@ -0,0 +1,67 @@ +A `'static` requirement in a return type involving a trait is not fulfilled. + +Erroneous code examples: + +```compile_fail,E0759 +use std::fmt::Debug; + +fn foo(x: &i32) -> impl Debug { + x +} +``` + +```compile_fail,E0759 +# use std::fmt::Debug; +fn bar(x: &i32) -> Box { + Box::new(x) +} +``` + +These examples have the same semantics as the following: + +```compile_fail,E0759 +# use std::fmt::Debug; +fn foo(x: &i32) -> impl Debug + 'static { + x +} +``` + +```compile_fail,E0759 +# use std::fmt::Debug; +fn bar(x: &i32) -> Box { + Box::new(x) +} +``` + +Both [`dyn Trait`] and [`impl Trait`] in return types have a an implicit +`'static` requirement, meaning that the value implementing them that is being +returned has to be either a `'static` borrow or an owned value. + +In order to change the requirement from `'static` to be a lifetime derived from +its arguments, you can add an explicit bound, either to an anonymous lifetime +`'_` or some appropriate named lifetime. + +``` +# use std::fmt::Debug; +fn foo(x: &i32) -> impl Debug + '_ { + x +} +fn bar(x: &i32) -> Box { + Box::new(x) +} +``` + +These are equivalent to the following explicit lifetime annotations: + +``` +# use std::fmt::Debug; +fn foo<'a>(x: &'a i32) -> impl Debug + 'a { + x +} +fn bar<'a>(x: &'a i32) -> Box { + Box::new(x) +} +``` + +[`dyn Trait`]: https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types +[`impl Trait`]: https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits diff --git a/src/librustc_infer/infer/error_reporting/nice_region_error/static_impl_trait.rs b/src/librustc_infer/infer/error_reporting/nice_region_error/static_impl_trait.rs index 5ad76e3964038..853a414290704 100644 --- a/src/librustc_infer/infer/error_reporting/nice_region_error/static_impl_trait.rs +++ b/src/librustc_infer/infer/error_reporting/nice_region_error/static_impl_trait.rs @@ -40,7 +40,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> { let mut err = struct_span_err!( self.tcx().sess, sp, - E0758, + E0759, "cannot infer an appropriate lifetime" ); err.span_label( diff --git a/src/test/ui/async-await/issues/issue-62097.stderr b/src/test/ui/async-await/issues/issue-62097.stderr index aa443b9d2fc16..0f58b158904db 100644 --- a/src/test/ui/async-await/issues/issue-62097.stderr +++ b/src/test/ui/async-await/issues/issue-62097.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/issue-62097.rs:12:31 | LL | pub async fn run_dummy_fn(&self) { @@ -11,4 +11,4 @@ LL | foo(|| self.bar()).await; error: aborting due to previous error -For more information about this error, try `rustc --explain E0758`. +For more information about this error, try `rustc --explain E0759`. diff --git a/src/test/ui/impl-trait/must_outlive_least_region_or_bound.stderr b/src/test/ui/impl-trait/must_outlive_least_region_or_bound.stderr index baed43783a13c..e1fa4f02b6fcf 100644 --- a/src/test/ui/impl-trait/must_outlive_least_region_or_bound.stderr +++ b/src/test/ui/impl-trait/must_outlive_least_region_or_bound.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:3:35 | LL | fn elided(x: &i32) -> impl Copy { x } @@ -16,7 +16,7 @@ help: to declare that the `impl Trait` captures data from argument `x`, you can LL | fn elided(x: &i32) -> impl Copy + '_ { x } | ^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:6:44 | LL | fn explicit<'a>(x: &'a i32) -> impl Copy { x } @@ -34,7 +34,7 @@ help: to declare that the `impl Trait` captures data from argument `x`, you can LL | fn explicit<'a>(x: &'a i32) -> impl Copy + 'a { x } | ^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:9:46 | LL | fn elided2(x: &i32) -> impl Copy + 'static { x } @@ -56,7 +56,7 @@ help: alternatively, add an explicit `'static` bound to this reference LL | fn elided2(x: &'static i32) -> impl Copy + 'static { x } | ^^^^^^^^^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:12:55 | LL | fn explicit2<'a>(x: &'a i32) -> impl Copy + 'static { x } @@ -86,7 +86,7 @@ LL | fn foo<'a>(x: &i32) -> impl Copy + 'a { x } | | | help: add explicit lifetime `'a` to the type of `x`: `&'a i32` -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:33:69 | LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'static { x } @@ -123,7 +123,7 @@ LL | fn ty_param_wont_outlive_static(x: T) -> impl Debug + 'static { | | | help: consider adding an explicit lifetime bound...: `T: 'static +` -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:18:50 | LL | fn elided3(x: &i32) -> Box { Box::new(x) } @@ -136,7 +136,7 @@ help: to declare that the trait object captures data from argument `x`, you can LL | fn elided3(x: &i32) -> Box { Box::new(x) } | ^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:21:59 | LL | fn explicit3<'a>(x: &'a i32) -> Box { Box::new(x) } @@ -149,7 +149,7 @@ help: to declare that the trait object captures data from argument `x`, you can LL | fn explicit3<'a>(x: &'a i32) -> Box { Box::new(x) } | ^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:24:60 | LL | fn elided4(x: &i32) -> Box { Box::new(x) } @@ -166,7 +166,7 @@ help: alternatively, add an explicit `'static` bound to this reference LL | fn elided4(x: &'static i32) -> Box { Box::new(x) } | ^^^^^^^^^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/must_outlive_least_region_or_bound.rs:27:69 | LL | fn explicit4<'a>(x: &'a i32) -> Box { Box::new(x) } @@ -183,5 +183,5 @@ LL | fn explicit4<'a>(x: &'static i32) -> Box { Box::new(x) error: aborting due to 12 previous errors -Some errors have detailed explanations: E0310, E0621, E0623, E0758. +Some errors have detailed explanations: E0310, E0621, E0623, E0759. For more information about an error, try `rustc --explain E0310`. diff --git a/src/test/ui/impl-trait/static-return-lifetime-infered.stderr b/src/test/ui/impl-trait/static-return-lifetime-infered.stderr index 90aada01d9917..df0db6e4fc6df 100644 --- a/src/test/ui/impl-trait/static-return-lifetime-infered.stderr +++ b/src/test/ui/impl-trait/static-return-lifetime-infered.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/static-return-lifetime-infered.rs:7:16 | LL | fn iter_values_anon(&self) -> impl Iterator { @@ -18,7 +18,7 @@ help: to declare that the `impl Trait` captures data from argument `self`, you c LL | fn iter_values_anon(&self) -> impl Iterator + '_ { | ^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/static-return-lifetime-infered.rs:11:16 | LL | fn iter_values<'a>(&'a self) -> impl Iterator { @@ -40,4 +40,4 @@ LL | fn iter_values<'a>(&'a self) -> impl Iterator + 'a { error: aborting due to 2 previous errors -For more information about this error, try `rustc --explain E0758`. +For more information about this error, try `rustc --explain E0759`. diff --git a/src/test/ui/issues/issue-16922.stderr b/src/test/ui/issues/issue-16922.stderr index ec80f6569f5ac..919594fc9af4b 100644 --- a/src/test/ui/issues/issue-16922.stderr +++ b/src/test/ui/issues/issue-16922.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/issue-16922.rs:4:14 | LL | fn foo(value: &T) -> Box { @@ -13,4 +13,4 @@ LL | fn foo(value: &T) -> Box { error: aborting due to previous error -For more information about this error, try `rustc --explain E0758`. +For more information about this error, try `rustc --explain E0759`. diff --git a/src/test/ui/object-lifetime/object-lifetime-default-from-box-error.stderr b/src/test/ui/object-lifetime/object-lifetime-default-from-box-error.stderr index d461001adead9..1b1e0d9610724 100644 --- a/src/test/ui/object-lifetime/object-lifetime-default-from-box-error.stderr +++ b/src/test/ui/object-lifetime/object-lifetime-default-from-box-error.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/object-lifetime-default-from-box-error.rs:18:5 | LL | fn load(ss: &mut SomeStruct) -> Box { @@ -23,5 +23,5 @@ LL | ss.r = b; error: aborting due to 2 previous errors -Some errors have detailed explanations: E0621, E0758. +Some errors have detailed explanations: E0621, E0759. For more information about an error, try `rustc --explain E0621`. diff --git a/src/test/ui/regions/region-object-lifetime-in-coercion.stderr b/src/test/ui/regions/region-object-lifetime-in-coercion.stderr index c684373c67e9d..7f5a3a47976c7 100644 --- a/src/test/ui/regions/region-object-lifetime-in-coercion.stderr +++ b/src/test/ui/regions/region-object-lifetime-in-coercion.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/region-object-lifetime-in-coercion.rs:8:46 | LL | fn a(v: &[u8]) -> Box { @@ -15,7 +15,7 @@ help: alternatively, add an explicit `'static` bound to this reference LL | fn a(v: &'static [u8]) -> Box { | ^^^^^^^^^^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/region-object-lifetime-in-coercion.rs:13:14 | LL | fn b(v: &[u8]) -> Box { @@ -32,7 +32,7 @@ help: alternatively, add an explicit `'static` bound to this reference LL | fn b(v: &'static [u8]) -> Box { | ^^^^^^^^^^^^^ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/region-object-lifetime-in-coercion.rs:19:14 | LL | fn c(v: &[u8]) -> Box { @@ -79,5 +79,5 @@ LL | Box::new(v) error: aborting due to 4 previous errors -Some errors have detailed explanations: E0495, E0758. +Some errors have detailed explanations: E0495, E0759. For more information about an error, try `rustc --explain E0495`. diff --git a/src/test/ui/regions/regions-close-object-into-object-2.stderr b/src/test/ui/regions/regions-close-object-into-object-2.stderr index c4ba395179831..114e4052aae09 100644 --- a/src/test/ui/regions/regions-close-object-into-object-2.stderr +++ b/src/test/ui/regions/regions-close-object-into-object-2.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/regions-close-object-into-object-2.rs:10:11 | LL | fn g<'a, T: 'static>(v: Box + 'a>) -> Box { @@ -17,4 +17,4 @@ LL | fn g<'a, T: 'static>(v: std::boxed::Box<(dyn A + 'static)>) -> Box $DIR/regions-close-object-into-object-4.rs:10:11 | LL | fn i<'a, T, U>(v: Box+'a>) -> Box { @@ -17,4 +17,4 @@ LL | fn i<'a, T, U>(v: std::boxed::Box<(dyn A + 'static)>) -> Box $DIR/regions-proc-bound-capture.rs:9:14 | LL | fn static_proc(x: &isize) -> Box (isize) + 'static> { @@ -18,4 +18,4 @@ LL | fn static_proc(x: &'static isize) -> Box (isize) + 'static> error: aborting due to previous error -For more information about this error, try `rustc --explain E0758`. +For more information about this error, try `rustc --explain E0759`. diff --git a/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait-async.stderr b/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait-async.stderr index 9b04069136be2..88bd990b1e81b 100644 --- a/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait-async.stderr +++ b/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait-async.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/arbitrary_self_types_pin_lifetime_impl_trait-async.rs:8:16 | LL | async fn f(self: Pin<&Self>) -> impl Clone { self } @@ -9,4 +9,4 @@ LL | async fn f(self: Pin<&Self>) -> impl Clone { self } error: aborting due to previous error -For more information about this error, try `rustc --explain E0758`. +For more information about this error, try `rustc --explain E0759`. diff --git a/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait.stderr b/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait.stderr index c37eb2d136ef1..2e10ab3d3f9b8 100644 --- a/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait.stderr +++ b/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/arbitrary_self_types_pin_lifetime_impl_trait.rs:6:44 | LL | fn f(self: Pin<&Self>) -> impl Clone { self } @@ -18,4 +18,4 @@ LL | fn f(self: Pin<&Self>) -> impl Clone + '_ { self } error: aborting due to previous error -For more information about this error, try `rustc --explain E0758`. +For more information about this error, try `rustc --explain E0759`. diff --git a/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.stderr b/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.stderr index 7e8ab1bfe1633..9ab060328537b 100644 --- a/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.stderr +++ b/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.stderr @@ -6,7 +6,7 @@ LL | fn baz(g: G, dest: &mut T) -> impl FnOnce() + '_ | | | help: consider introducing lifetime `'a` here: `'a,` -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/missing-lifetimes-in-signature.rs:19:5 | LL | fn foo(g: G, dest: &mut T) -> impl FnOnce() @@ -125,5 +125,5 @@ LL | fn bak<'a, G, T>(g: G, dest: &'a mut T) -> impl FnOnce() + 'a error: aborting due to 7 previous errors -Some errors have detailed explanations: E0261, E0309, E0621, E0758. +Some errors have detailed explanations: E0261, E0309, E0621, E0759. For more information about an error, try `rustc --explain E0261`. diff --git a/src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr b/src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr index fc4c801949512..dda5de431d309 100644 --- a/src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr +++ b/src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr @@ -1,4 +1,4 @@ -error[E0758]: cannot infer an appropriate lifetime +error[E0759]: cannot infer an appropriate lifetime --> $DIR/dyn-trait-underscore.rs:8:20 | LL | fn a(items: &[T]) -> Box> { @@ -14,4 +14,4 @@ LL | fn a(items: &[T]) -> Box + '_> { error: aborting due to previous error -For more information about this error, try `rustc --explain E0758`. +For more information about this error, try `rustc --explain E0759`.