Rollup merge of #70038 - DutchGhost:const-forget-tests, r=RalfJung

Remove the call that makes miri fail

Fixes the concern raised in https://github.com/rust-lang/rust/pull/69645/files#r392884274

cc @RalfJung

diff --git a/src/libcore/tests/mem.rs b/src/libcore/tests/mem.rs
index 8337ab103419f82d6406359fbd0a542760b45818..59588d97787b7adc19a93b15b83868fe8f980614 100644 (file)
--- a/src/libcore/tests/mem.rs
+++ b/src/libcore/tests/mem.rs
@@ -129,21 +129,3 @@ fn is_send_sync<T: Send + Sync>() {}
     is_send_sync::<Discriminant<Regular>>();
     is_send_sync::<Discriminant<NotSendSync>>();
 }
-
-#[test]
-fn test_const_forget() {
-    const _: () = forget(0i32);
-    const _: () = forget(Vec::<Vec<Box<i32>>>::new());
-
-    // Writing this function signature without const-forget
-    // triggers compiler errors:
-    // 1) That we use a non-const fn inside a const fn
-    // 2) without the forget, it complains about the destructor of Box
-    const fn const_forget_box<T>(x: Box<T>) {
-        forget(x);
-    }
-
-    // Call the forget_box at runtime,
-    // as we can't const-construct a box yet.
-    const_forget_box(Box::new(0i32));
-}

diff --git a/src/test/ui/consts/const_forget.rs b/src/test/ui/consts/const_forget.rs
new file mode 100644 (file)
index 0000000..2dcb72a
--- /dev/null
+++ b/src/test/ui/consts/const_forget.rs
@@ -0,0 +1,22 @@
+// check-pass
+
+#![feature(const_forget)]
+
+use std::mem::forget;
+
+const _: () = forget(0i32);
+const _: () = forget(Vec::<Vec<Box<i32>>>::new());
+
+// Writing this function signature without const-forget
+// triggers compiler errors:
+// 1) That we use a non-const fn inside a const fn
+// 2) without the forget, it complains about the destructor of Box
+//
+// FIXME: this method cannot be called in const-eval yet, as Box isn't
+// const constructable
+#[allow(unused)]
+const fn const_forget_box<T: ?Sized>(b: Box<T>) {
+    forget(b);
+}
+
+fn main() {}