Rollup merge of #114779 - MU001999:fix/114701, r=petrochenkov

Add check before suggest removing parens

Fixes #114701

2 files changed, 30 insertions, 0 deletions

diff --git a/tests/ui/suggestions/issue-114701.rs b/tests/ui/suggestions/issue-114701.rs
new file mode 100644
index 00000000000..81d7803ec8c
--- /dev/null
+++ b/tests/ui/suggestions/issue-114701.rs
@@ -0,0 +1,15 @@
+enum Enum<T> { SVariant { v: T }, UVariant }
+
+macro_rules! is_variant {
+    (TSVariant, ) => (!);
+    (SVariant, ) => (!);
+    (UVariant, $expr:expr) => (is_variant!(@check UVariant, {}, $expr));
+    (@check $variant:ident, $matcher:tt, $expr:expr) => (
+        assert!(if let Enum::$variant::<()> $matcher = $expr () { true } else { false },
+                );
+    );
+}
+
+fn main() {
+    is_variant!(UVariant, Enum::<()>::UVariant); //~ ERROR expected function
+}
diff --git a/tests/ui/suggestions/issue-114701.stderr b/tests/ui/suggestions/issue-114701.stderr
new file mode 100644
index 00000000000..67462a09c78
--- /dev/null
+++ b/tests/ui/suggestions/issue-114701.stderr
@@ -0,0 +1,15 @@
+error[E0618]: expected function, found `Enum<()>`
+  --> $DIR/issue-114701.rs:14:27
+   |
+LL | enum Enum<T> { SVariant { v: T }, UVariant }
+   |                                   -------- `Enum::UVariant` defined here
+...
+LL |         assert!(if let Enum::$variant::<()> $matcher = $expr () { true } else { false },
+   |                                                        -------- call expression requires function
+...
+LL |     is_variant!(UVariant, Enum::<()>::UVariant);
+   |                           ^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0618`.