+// allow(const_err) to work around a bug in warnings
+#[allow(const_err)]
+static FOO: fn() = || { assert_ne!(42, 43) };
+#[allow(const_err)]
+static BAR: fn(i32, i32) = |a, b| { assert_ne!(a, b) };
+
+// use to first make the closure FnOnce() before making it fn()
+fn magic0<R, F: FnOnce() -> R>(f: F) -> F { f }
+fn magic1<T, R, F: FnOnce(T) -> R>(f: F) -> F { f }
+
+fn main() {
+ FOO();
+ BAR(44, 45);
+ let bar: unsafe fn(i32, i32) = BAR;
+ unsafe { bar(46, 47) };
+ let boo: &dyn Fn(i32, i32) = &BAR;
+ boo(48, 49);
+
+ let f: fn() = ||{};
+ f();
+ let f = magic0(||{}) as fn();
+ f();
+
+ let g: fn(i32) = |i| assert_eq!(i, 2);
+ g(2);
+ let g = magic1(|i| assert_eq!(i, 2)) as fn(i32);
+ g(2);
+
+ // FIXME: This fails with "invalid use of NULL pointer"
+ //let h: fn() -> ! = || std::process::exit(0);
+ //h();
+ // FIXME: This does not even compile?!? <https://github.com/rust-lang/rust/issues/66738>
+ //let h = magic0(|| std::process::exit(0)) as fn() -> !;
+ //h();
+ // Once these tests pass, they should be in separate files as they terminate the process.
+}