From 8075e05c16f8593973298c2c92beb50b6b430e03 Mon Sep 17 00:00:00 2001
From: Takayuki Maeda <takoyaki0316@gmail.com>
Date: Tue, 28 Jun 2022 20:01:38 +0900
Subject: [PATCH] add regression test for #79495

---
 src/test/rustdoc-ui/issue-79495.rs     | 16 ++++++++++++++++
 src/test/rustdoc-ui/issue-79495.stderr | 13 +++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 src/test/rustdoc-ui/issue-79495.rs
 create mode 100644 src/test/rustdoc-ui/issue-79495.stderr

diff --git a/src/test/rustdoc-ui/issue-79495.rs b/src/test/rustdoc-ui/issue-79495.rs
new file mode 100644
index 0000000000000..f927dd189038a
--- /dev/null
+++ b/src/test/rustdoc-ui/issue-79495.rs
@@ -0,0 +1,16 @@
+#![feature(arbitrary_enum_discriminant, core_intrinsics)]
+
+extern crate core;
+use core::intrinsics::discriminant_value;
+
+#[repr(usize)]
+enum MyWeirdOption<T> {
+    None = 0,
+    Some(T) = std::mem::size_of::<T>(),
+    //~^ ERROR generic parameters may not be used in const operations
+}
+
+fn main() {
+    assert_eq!(discriminant_value(&MyWeirdOption::<u8>::None), 0);
+    assert_eq!(discriminant_value(&MyWeirdOption::Some(0u8)), 1);
+}
diff --git a/src/test/rustdoc-ui/issue-79495.stderr b/src/test/rustdoc-ui/issue-79495.stderr
new file mode 100644
index 0000000000000..4fe75950796dd
--- /dev/null
+++ b/src/test/rustdoc-ui/issue-79495.stderr
@@ -0,0 +1,13 @@
+error: generic parameters may not be used in const operations
+  --> $DIR/issue-79495.rs:9:35
+   |
+LL |     Some(T) = std::mem::size_of::<T>(),
+   |                                   ^ cannot perform const operation using `T`
+   |
+   = note: type parameters may not be used in const expressions
+   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+
+error: Compilation failed, aborting rustdoc
+
+error: aborting due to 2 previous errors
+