1 files changed, 19 insertions, 0 deletions
diff --git a/tests/ui/consts/issue-79137-toogeneric.rs b/tests/ui/consts/issue-79137-toogeneric.rs
new file mode 100644
index 000000000..456035458
--- /dev/null
+++ b/tests/ui/consts/issue-79137-toogeneric.rs
@@ -0,0 +1,19 @@
+// Test that `variant_count` only gets evaluated once the type is concrete enough.
+
+#![feature(variant_count)]
+
+pub struct GetVariantCount<T>(T);
+
+impl<T> GetVariantCount<T> {
+    pub const VALUE: usize = std::mem::variant_count::<T>();
+}
+
+const fn check_variant_count<T>() -> bool {
+    matches!(GetVariantCount::<T>::VALUE, GetVariantCount::<T>::VALUE)
+    //~^ ERROR constant pattern depends on a generic parameter
+    //~| ERROR constant pattern depends on a generic parameter
+}
+
+fn main() {
+    assert!(check_variant_count::<Option<()>>());
+}