Rollup merge of #99835 - TaKO8Ki:suggest-adding-or-removing-ref-for-binding-pattern, r=estebank

Suggest adding/removing `ref` for binding patterns

This fixes what a fixme comment says.

r? `@estebank`

7 files changed, 111 insertions, 2 deletions

diff --git a/src/test/ui/mismatched_types/E0409.stderr b/src/test/ui/mismatched_types/E0409.stderr
index ef03b67b1b0..7fec6ecd725 100644
--- a/src/test/ui/mismatched_types/E0409.stderr
+++ b/src/test/ui/mismatched_types/E0409.stderr
@@ -17,6 +17,10 @@ LL |         (0, ref y) | (y, 0) => {}
    |             first introduced with type `&{integer}` here
    |
    = note: in the same arm, a binding must have the same type in all alternatives
+help: consider adding `ref`
+   |
+LL |         (0, ref y) | (ref y, 0) => {}
+   |                       +++
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.fixed b/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.fixed
new file mode 100644
index 00000000000..56f93cfbfdc
--- /dev/null
+++ b/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.fixed
@@ -0,0 +1,21 @@
+// run-rustfix
+#![allow(dead_code, unused_variables)]
+
+fn main() {
+    enum Blah {
+        A(isize, isize, usize),
+        B(isize, usize),
+    }
+
+    match Blah::A(1, 1, 2) {
+        Blah::A(_, x, ref y) | Blah::B(x, ref y) => {}
+        //~^ ERROR mismatched types
+        //~| ERROR variable `y` is bound inconsistently across alternatives separated by `|`
+    }
+
+    match Blah::A(1, 1, 2) {
+        Blah::A(_, x, y) | Blah::B(x, y) => {}
+        //~^ ERROR mismatched types
+        //~| variable `y` is bound inconsistently across alternatives separated by `|`
+    }
+}
diff --git a/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.rs b/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.rs
new file mode 100644
index 00000000000..0c33f99a42e
--- /dev/null
+++ b/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.rs
@@ -0,0 +1,21 @@
+// run-rustfix
+#![allow(dead_code, unused_variables)]
+
+fn main() {
+    enum Blah {
+        A(isize, isize, usize),
+        B(isize, usize),
+    }
+
+    match Blah::A(1, 1, 2) {
+        Blah::A(_, x, ref y) | Blah::B(x, y) => {}
+        //~^ ERROR mismatched types
+        //~| ERROR variable `y` is bound inconsistently across alternatives separated by `|`
+    }
+
+    match Blah::A(1, 1, 2) {
+        Blah::A(_, x, y) | Blah::B(x, ref y) => {}
+        //~^ ERROR mismatched types
+        //~| variable `y` is bound inconsistently across alternatives separated by `|`
+    }
+}
diff --git a/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.stderr b/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.stderr
new file mode 100644
index 00000000000..e8357f9a37f
--- /dev/null
+++ b/src/test/ui/mismatched_types/suggest-adding-or-removing-ref-for-binding-pattern.stderr
@@ -0,0 +1,49 @@
+error[E0409]: variable `y` is bound inconsistently across alternatives separated by `|`
+  --> $DIR/suggest-adding-or-removing-ref-for-binding-pattern.rs:11:43
+   |
+LL |         Blah::A(_, x, ref y) | Blah::B(x, y) => {}
+   |                           - first binding ^ bound in different ways
+
+error[E0409]: variable `y` is bound inconsistently across alternatives separated by `|`
+  --> $DIR/suggest-adding-or-removing-ref-for-binding-pattern.rs:17:43
+   |
+LL |         Blah::A(_, x, y) | Blah::B(x, ref y) => {}
+   |                       - first binding     ^ bound in different ways
+
+error[E0308]: mismatched types
+  --> $DIR/suggest-adding-or-removing-ref-for-binding-pattern.rs:11:43
+   |
+LL |     match Blah::A(1, 1, 2) {
+   |           ---------------- this expression has type `Blah`
+LL |         Blah::A(_, x, ref y) | Blah::B(x, y) => {}
+   |                       -----               ^ expected `&usize`, found `usize`
+   |                       |
+   |                       first introduced with type `&usize` here
+   |
+   = note: in the same arm, a binding must have the same type in all alternatives
+help: consider adding `ref`
+   |
+LL |         Blah::A(_, x, ref y) | Blah::B(x, ref y) => {}
+   |                                           +++
+
+error[E0308]: mismatched types
+  --> $DIR/suggest-adding-or-removing-ref-for-binding-pattern.rs:17:39
+   |
+LL |     match Blah::A(1, 1, 2) {
+   |           ---------------- this expression has type `Blah`
+LL |         Blah::A(_, x, y) | Blah::B(x, ref y) => {}
+   |                       -               ^^^^^ expected `usize`, found `&usize`
+   |                       |
+   |                       first introduced with type `usize` here
+   |
+   = note: in the same arm, a binding must have the same type in all alternatives
+help: consider removing `ref`
+   |
+LL -         Blah::A(_, x, y) | Blah::B(x, ref y) => {}
+LL +         Blah::A(_, x, y) | Blah::B(x, y) => {}
+   |
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0308, E0409.
+For more information about an error, try `rustc --explain E0308`.
diff --git a/src/test/ui/resolve/resolve-inconsistent-binding-mode.stderr b/src/test/ui/resolve/resolve-inconsistent-binding-mode.stderr
index 96c1869b4e7..c805c9eb125 100644
--- a/src/test/ui/resolve/resolve-inconsistent-binding-mode.stderr
+++ b/src/test/ui/resolve/resolve-inconsistent-binding-mode.stderr
@@ -31,6 +31,10 @@ LL |         Opts::A(ref i) | Opts::B(i) => {}
    |                 first introduced with type `&isize` here
    |
    = note: in the same arm, a binding must have the same type in all alternatives
+help: consider adding `ref`
+   |
+LL |         Opts::A(ref i) | Opts::B(ref i) => {}
+   |                                  +++
 
 error[E0308]: mismatched types
   --> $DIR/resolve-inconsistent-binding-mode.rs:18:34
@@ -43,6 +47,10 @@ LL |         Opts::A(ref i) | Opts::B(i) => {}
    |                 first introduced with type `&isize` here
    |
    = note: in the same arm, a binding must have the same type in all alternatives
+help: consider adding `ref`
+   |
+LL |         Opts::A(ref i) | Opts::B(ref i) => {}
+   |                                  +++
 
 error[E0308]: mismatched types
   --> $DIR/resolve-inconsistent-binding-mode.rs:27:38
diff --git a/src/test/ui/resolve/resolve-inconsistent-names.rs b/src/test/ui/resolve/resolve-inconsistent-names.rs
index 989d2d45230..9a40b20346c 100644
--- a/src/test/ui/resolve/resolve-inconsistent-names.rs
+++ b/src/test/ui/resolve/resolve-inconsistent-names.rs
@@ -23,6 +23,7 @@ fn main() {
         //~| ERROR mismatched types
         //~| ERROR variable `c` is not bound in all patterns
         //~| HELP if you meant to match on unit variant `E::A`, use the full path in the pattern
+        //~| HELP consider removing `ref`
     }
 
     let z = (10, 20);
diff --git a/src/test/ui/resolve/resolve-inconsistent-names.stderr b/src/test/ui/resolve/resolve-inconsistent-names.stderr
index 9de191f7d32..773c9f6cd11 100644
--- a/src/test/ui/resolve/resolve-inconsistent-names.stderr
+++ b/src/test/ui/resolve/resolve-inconsistent-names.stderr
@@ -55,7 +55,7 @@ LL |         (A, B) | (ref B, c) | (c, A) => ()
    |             first binding
 
 error[E0408]: variable `CONST1` is not bound in all patterns
-  --> $DIR/resolve-inconsistent-names.rs:30:23
+  --> $DIR/resolve-inconsistent-names.rs:31:23
    |
 LL |         (CONST1, _) | (_, Const2) => ()
    |          ------       ^^^^^^^^^^^ pattern doesn't bind `CONST1`
@@ -69,7 +69,7 @@ LL |     const CONST1: usize = 10;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ not accessible
 
 error[E0408]: variable `Const2` is not bound in all patterns
-  --> $DIR/resolve-inconsistent-names.rs:30:9
+  --> $DIR/resolve-inconsistent-names.rs:31:9
    |
 LL |         (CONST1, _) | (_, Const2) => ()
    |         ^^^^^^^^^^^       ------ variable not in all patterns
@@ -92,6 +92,11 @@ LL |         (A, B) | (ref B, c) | (c, A) => ()
    |             first introduced with type `E` here
    |
    = note: in the same arm, a binding must have the same type in all alternatives
+help: consider removing `ref`
+   |
+LL -         (A, B) | (ref B, c) | (c, A) => ()
+LL +         (A, B) | (B, c) | (c, A) => ()
+   |
 
 error: aborting due to 9 previous errors