When mentioning lifetimes, put either the trait ref or the self type closer to the...

When mentioning lifetimes, only invert wording between the expected trait and the self type when the self type has the vid.
This way, the lifetimes always stay close to the self type or trait ref that actually contains them.

diff --git a/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs b/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
index a0ce250d7e977fe86f2a6fc329b29b5f9eb097d7..391539b77bc46485321841b7bba279b2b651b8d2 100644 (file)
--- a/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
+++ b/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
@@ -251,10 +251,16 @@ fn try_report_placeholders_trait(
             }
         });
 
-        let self_ty_has_vid = self
+        let actual_self_ty_has_vid = self
             .tcx()
             .any_free_region_meets(&actual_trait_ref.self_ty(), |r| Some(r) == vid);
 
+        let expected_self_ty_has_vid = self
+            .tcx()
+            .any_free_region_meets(&expected_trait_ref.self_ty(), |r| Some(r) == vid);
+
+        let self_ty_has_vid = actual_self_ty_has_vid || expected_self_ty_has_vid;
+
         debug!(
             "try_report_placeholders_trait: actual_has_vid={:?}",
             actual_has_vid
@@ -266,8 +272,12 @@ fn try_report_placeholders_trait(
         debug!("try_report_placeholders_trait: has_sub={:?}", has_sub);
         debug!("try_report_placeholders_trait: has_sup={:?}", has_sup);
         debug!(
-            "try_report_placeholders_trait: self_ty_has_vid={:?}",
-            self_ty_has_vid
+            "try_report_placeholders_trait: actual_self_ty_has_vid={:?}",
+            actual_self_ty_has_vid
+        );
+        debug!(
+            "try_report_placeholders_trait: expected_self_ty_has_vid={:?}",
+            expected_self_ty_has_vid
         );
 
         // The weird thing here with the `maybe_highlighting_region` calls and the
@@ -289,23 +299,43 @@ fn try_report_placeholders_trait(
             RegionHighlightMode::maybe_highlighting_region(sup_placeholder, has_sup, || {
                 match (has_sub, has_sup) {
                     (Some(n1), Some(n2)) => {
-                        err.note(&format!(
-                            "`{}` would have to be implemented for the type `{}`, \
-                             for any two lifetimes `'{}` and `'{}`",
-                            expected_trait_ref,
-                            expected_trait_ref.self_ty(),
-                            std::cmp::min(n1, n2),
-                            std::cmp::max(n1, n2),
-                        ));
+                        if self_ty_has_vid {
+                            err.note(&format!(
+                                "`{}` would have to be implemented for the type `{}`, \
+                                 for any two lifetimes `'{}` and `'{}`",
+                                expected_trait_ref,
+                                expected_trait_ref.self_ty(),
+                                std::cmp::min(n1, n2),
+                                std::cmp::max(n1, n2),
+                            ));
+                        } else {
+                            err.note(&format!(
+                                "`{}` must implement `{}`, \
+                                 for any two lifetimes `'{}` and `'{}`",
+                                expected_trait_ref.self_ty(),
+                                expected_trait_ref,
+                                std::cmp::min(n1, n2),
+                                std::cmp::max(n1, n2),
+                            ));
+                        }
                     }
                     (Some(n), _) | (_, Some(n)) => {
-                        err.note(&format!(
-                            "`{}` would have to be implemented for the type `{}`, \
-                             for any lifetime `'{}`",
-                            expected_trait_ref,
-                            expected_trait_ref.self_ty(),
-                            n,
-                        ));
+                        if self_ty_has_vid {
+                            err.note(&format!(
+                                "`{}` would have to be implemented for the type `{}`, \
+                                 for any lifetime `'{}`",
+                                expected_trait_ref,
+                                expected_trait_ref.self_ty(),
+                                n,
+                            ));
+                        } else {
+                            err.note(&format!(
+                                "`{}` must implement `{}`, for any lifetime `'{}`",
+                                expected_trait_ref.self_ty(),
+                                expected_trait_ref,
+                                n,
+                            ));
+                        }
                     }
                     (None, None) => RegionHighlightMode::maybe_highlighting_region(
                         vid,
@@ -320,11 +350,19 @@ fn try_report_placeholders_trait(
                                     n,
                                 ));
                             } else {
-                                err.note(&format!(
-                                    "`{}` would have to be implemented for the type `{}`",
-                                    expected_trait_ref,
-                                    expected_trait_ref.self_ty(),
-                                ));
+                                if self_ty_has_vid {
+                                    err.note(&format!(
+                                        "`{}` would have to be implemented for the type `{}`",
+                                        expected_trait_ref,
+                                        expected_trait_ref.self_ty(),
+                                    ));
+                                } else {
+                                    err.note(&format!(
+                                        "`{}` must implement `{}`",
+                                        expected_trait_ref.self_ty(),
+                                        expected_trait_ref,
+                                    ));
+                                }
                             }
                         },
                     ),
@@ -347,10 +385,9 @@ fn try_report_placeholders_trait(
                         ));
                     } else {
                         err.note(&format!(
-                            "but `{}` is actually implemented for the type `{}`, \
-                             for some lifetime `'{}`",
-                            actual_trait_ref,
+                            "but `{}` actually implements `{}`, for some lifetime `'{}`",
                             actual_trait_ref.self_ty(),
+                            actual_trait_ref,
                             n
                         ));
                     }

diff --git a/src/test/ui/associated-types/associated-types-eq-hr.stderr b/src/test/ui/associated-types/associated-types-eq-hr.stderr
index 0e471a78d9ed8490069cf3407c42b5af314350d9..5a074fe345734692c2d85a7d7dfb90e548cea8fc 100644 (file)
--- a/src/test/ui/associated-types/associated-types-eq-hr.stderr
+++ b/src/test/ui/associated-types/associated-types-eq-hr.stderr
@@ -41,8 +41,8 @@ LL |     tuple_one::<Tuple>();
    |     ^^^^^^^^^^^^^^^^^^
    |
    = note: Due to a where-clause on `tuple_one`,
-   = note: `TheTrait<(&'0 isize, &'1 isize)>` would have to be implemented for the type `Tuple`, for any two lifetimes `'0` and `'1`
-   = note: but `TheTrait<(&'2 isize, &'2 isize)>` is actually implemented for the type `Tuple`, for some lifetime `'2`
+   = note: `Tuple` must implement `TheTrait<(&'0 isize, &'1 isize)>`, for any two lifetimes `'0` and `'1`
+   = note: but `Tuple` actually implements `TheTrait<(&'2 isize, &'2 isize)>`, for some lifetime `'2`
 
 error: implementation of `TheTrait` is not general enough
   --> $DIR/associated-types-eq-hr.rs:96:5
@@ -51,8 +51,8 @@ LL |     tuple_two::<Tuple>();
    |     ^^^^^^^^^^^^^^^^^^
    |
    = note: Due to a where-clause on `tuple_two`,
-   = note: `TheTrait<(&'0 isize, &'1 isize)>` would have to be implemented for the type `Tuple`, for any two lifetimes `'0` and `'1`
-   = note: but `TheTrait<(&'2 isize, &'2 isize)>` is actually implemented for the type `Tuple`, for some lifetime `'2`
+   = note: `Tuple` must implement `TheTrait<(&'0 isize, &'1 isize)>`, for any two lifetimes `'0` and `'1`
+   = note: but `Tuple` actually implements `TheTrait<(&'2 isize, &'2 isize)>`, for some lifetime `'2`
 
 error: implementation of `TheTrait` is not general enough
   --> $DIR/associated-types-eq-hr.rs:105:5
@@ -61,8 +61,8 @@ LL |     tuple_four::<Tuple>();
    |     ^^^^^^^^^^^^^^^^^^^
    |
    = note: Due to a where-clause on `tuple_four`,
-   = note: `TheTrait<(&'0 isize, &'1 isize)>` would have to be implemented for the type `Tuple`, for any two lifetimes `'0` and `'1`
-   = note: but `TheTrait<(&'2 isize, &'2 isize)>` is actually implemented for the type `Tuple`, for some lifetime `'2`
+   = note: `Tuple` must implement `TheTrait<(&'0 isize, &'1 isize)>`, for any two lifetimes `'0` and `'1`
+   = note: but `Tuple` actually implements `TheTrait<(&'2 isize, &'2 isize)>`, for some lifetime `'2`
 
 error: aborting due to 5 previous errors
 

diff --git a/src/test/ui/hrtb/hrtb-cache-issue-54302.stderr b/src/test/ui/hrtb/hrtb-cache-issue-54302.stderr
index 1aa0a7ca32bd1f23e8013ecaadc3c0def109d976..d0bcebeac4f70e5eb9fbf035d45c786a1f3662ed 100644 (file)
--- a/src/test/ui/hrtb/hrtb-cache-issue-54302.stderr
+++ b/src/test/ui/hrtb/hrtb-cache-issue-54302.stderr
@@ -4,8 +4,8 @@ error: implementation of `Deserialize` is not general enough
 LL |     assert_deserialize_owned::<&'static str>(); //~ ERROR
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: `Deserialize<'0>` would have to be implemented for the type `&'static str`, for any lifetime `'0`
-   = note: but `Deserialize<'1>` is actually implemented for the type `&str`, for some lifetime `'1`
+   = note: `&'static str` must implement `Deserialize<'0>`, for any lifetime `'0`
+   = note: but `&str` actually implements `Deserialize<'1>`, for some lifetime `'1`
 
 error: aborting due to previous error
 

diff --git a/src/test/ui/hrtb/hrtb-conflate-regions.stderr b/src/test/ui/hrtb/hrtb-conflate-regions.stderr
index 4c4f797988049082424cb824010067427ba29789..aa91314b350a1475ae970d0a5011976f56576b25 100644 (file)
--- a/src/test/ui/hrtb/hrtb-conflate-regions.stderr
+++ b/src/test/ui/hrtb/hrtb-conflate-regions.stderr
@@ -5,8 +5,8 @@ LL | fn b() { want_foo2::<SomeStruct>(); } //~ ERROR
    |          ^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: Due to a where-clause on `want_foo2`,
-   = note: `Foo<(&'0 isize, &'1 isize)>` would have to be implemented for the type `SomeStruct`, for any two lifetimes `'0` and `'1`
-   = note: but `Foo<(&'2 isize, &'2 isize)>` is actually implemented for the type `SomeStruct`, for some lifetime `'2`
+   = note: `SomeStruct` must implement `Foo<(&'0 isize, &'1 isize)>`, for any two lifetimes `'0` and `'1`
+   = note: but `SomeStruct` actually implements `Foo<(&'2 isize, &'2 isize)>`, for some lifetime `'2`
 
 error: aborting due to previous error
 

diff --git a/src/test/ui/hrtb/hrtb-exists-forall-trait-invariant.stderr b/src/test/ui/hrtb/hrtb-exists-forall-trait-invariant.stderr
index 916a524939b6b51201b0ea9832f184fc5f973ef5..91b5db6cd664fe76ff4f9f5e95af38b330071145 100644 (file)
--- a/src/test/ui/hrtb/hrtb-exists-forall-trait-invariant.stderr
+++ b/src/test/ui/hrtb/hrtb-exists-forall-trait-invariant.stderr
@@ -5,8 +5,8 @@ LL |     foo::<()>(); //~ ERROR not general enough
    |     ^^^^^^^^^
    |
    = note: Due to a where-clause on `foo`,
-   = note: `Trait<for<'b> fn(std::cell::Cell<&'b u32>)>` would have to be implemented for the type `()`
-   = note: but `Trait<fn(std::cell::Cell<&'0 u32>)>` is actually implemented for the type `()`, for some lifetime `'0`
+   = note: `()` must implement `Trait<for<'b> fn(std::cell::Cell<&'b u32>)>`
+   = note: but `()` actually implements `Trait<fn(std::cell::Cell<&'0 u32>)>`, for some lifetime `'0`
 
 error: aborting due to previous error
 

diff --git a/src/test/ui/hrtb/hrtb-just-for-static.stderr b/src/test/ui/hrtb/hrtb-just-for-static.stderr
index bd6e3dbebd2f5c1cf09305080b0da12a909560a9..24edcd910764ef08ca5748eb5046ae935074fc5b 100644 (file)
--- a/src/test/ui/hrtb/hrtb-just-for-static.stderr
+++ b/src/test/ui/hrtb/hrtb-just-for-static.stderr
@@ -5,8 +5,8 @@ LL |     want_hrtb::<StaticInt>() //~ ERROR
    |     ^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: Due to a where-clause on `want_hrtb`,
-   = note: `Foo<&'0 isize>` would have to be implemented for the type `StaticInt`, for any lifetime `'0`
-   = note: but `Foo<&'1 isize>` is actually implemented for the type `StaticInt`, for some lifetime `'1`
+   = note: `StaticInt` must implement `Foo<&'0 isize>`, for any lifetime `'0`
+   = note: but `StaticInt` actually implements `Foo<&'1 isize>`, for some lifetime `'1`
 
 error: implementation of `Foo` is not general enough
   --> $DIR/hrtb-just-for-static.rs:30:5

diff --git a/src/test/ui/hrtb/hrtb-perfect-forwarding.stderr b/src/test/ui/hrtb/hrtb-perfect-forwarding.stderr
index 8b71a8a800e50d67f8cdeec32318fdc1fb119011..a87fa6d3012da8a999319fa5b4e66eaf79f452fd 100644 (file)
--- a/src/test/ui/hrtb/hrtb-perfect-forwarding.stderr
+++ b/src/test/ui/hrtb/hrtb-perfect-forwarding.stderr
@@ -5,8 +5,8 @@ LL |     foo_hrtb_bar_not(&mut t); //~ ERROR not general enough
    |     ^^^^^^^^^^^^^^^^
    |
    = note: Due to a where-clause on `foo_hrtb_bar_not`,
-   = note: `Foo<&'0 isize>` would have to be implemented for the type `&mut T`, for any lifetime `'0`
-   = note: but `Foo<&'1 isize>` is actually implemented for the type `&mut T`, for some lifetime `'1`
+   = note: `&mut T` must implement `Foo<&'0 isize>`, for any lifetime `'0`
+   = note: but `&mut T` actually implements `Foo<&'1 isize>`, for some lifetime `'1`
 
 error: aborting due to previous error
 

diff --git a/src/test/ui/issues/issue-54302.stderr b/src/test/ui/issues/issue-54302.stderr
index ddf0414faf63f727826b7b4f9a8af292bdd2b3eb..442d32eb9f1e9e9d2d919d2c9b11972d98cc08a0 100644 (file)
--- a/src/test/ui/issues/issue-54302.stderr
+++ b/src/test/ui/issues/issue-54302.stderr
@@ -4,8 +4,8 @@ error: implementation of `Deserialize` is not general enough
 LL |     assert_deserialize_owned::<&'static str>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: `Deserialize<'0>` would have to be implemented for the type `&'static str`, for any lifetime `'0`
-   = note: but `Deserialize<'1>` is actually implemented for the type `&str`, for some lifetime `'1`
+   = note: `&'static str` must implement `Deserialize<'0>`, for any lifetime `'0`
+   = note: but `&str` actually implements `Deserialize<'1>`, for some lifetime `'1`
 
 error: aborting due to previous error