Auto merge of #50072 - oli-obk:discriminants, r=eddyb

Allow variant discriminant initializers to refer to other initializer…

…s of the same enum

r? @eddyb

fixes the 2.4 failure of https://github.com/rust-lang/rust/issues/49765

cc @durka @retep998

1 files changed, 36 insertions, 0 deletions

diff --git a/src/test/ui/const-eval/enum_discr.rs b/src/test/ui/const-eval/enum_discr.rs
new file mode 100644
index 00000000000..ba38a42092e
--- /dev/null
+++ b/src/test/ui/const-eval/enum_discr.rs
@@ -0,0 +1,36 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-pass
+// run-pass
+
+enum Foo {
+    X = 42,
+    Y = Foo::X as isize - 3,
+}
+
+enum Bar {
+    X,
+    Y = Bar::X as isize + 2,
+}
+
+enum Boo {
+    X = Boo::Y as isize * 2,
+    Y = 9,
+}
+
+fn main() {
+    assert_eq!(Foo::X as isize, 42);
+    assert_eq!(Foo::Y as isize, 39);
+    assert_eq!(Bar::X as isize, 0);
+    assert_eq!(Bar::Y as isize, 2);
+    assert_eq!(Boo::X as isize, 18);
+    assert_eq!(Boo::Y as isize, 9);
+}