1 files changed, 40 insertions, 0 deletions
diff --git a/tests/ui/derives/derive-partial-ord-discriminant-64bit.rs b/tests/ui/derives/derive-partial-ord-discriminant-64bit.rs
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index 00000000000..5b6bf6fbf1f
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+++ b/tests/ui/derives/derive-partial-ord-discriminant-64bit.rs
@@ -0,0 +1,40 @@
+//! Regression test for https://github.com/rust-lang/rust/issues/15523
+
+//@ run-pass
+// Issue 15523: derive(PartialOrd) should use the provided
+// discriminant values for the derived ordering.
+//
+// This test is checking corner cases that arise when you have
+// 64-bit values in the variants.
+
+#[derive(PartialEq, PartialOrd)]
+#[repr(u64)]
+enum Eu64 {
+    Pos2 = 2,
+    PosMax = !0,
+    Pos1 = 1,
+}
+
+#[derive(PartialEq, PartialOrd)]
+#[repr(i64)]
+enum Ei64 {
+    Pos2 = 2,
+    Neg1 = -1,
+    NegMin = 1 << 63,
+    PosMax = !(1 << 63),
+    Pos1 = 1,
+}
+
+fn main() {
+    assert!(Eu64::Pos2 > Eu64::Pos1);
+    assert!(Eu64::Pos2 < Eu64::PosMax);
+    assert!(Eu64::Pos1 < Eu64::PosMax);
+
+    assert!(Ei64::Pos2 > Ei64::Pos1);
+    assert!(Ei64::Pos2 > Ei64::Neg1);
+    assert!(Ei64::Pos1 > Ei64::Neg1);
+    assert!(Ei64::Pos2 > Ei64::NegMin);
+    assert!(Ei64::Pos1 > Ei64::NegMin);
+    assert!(Ei64::Pos2 < Ei64::PosMax);
+    assert!(Ei64::Pos1 < Ei64::PosMax);
+}