[libcore/cmp] Expand Ord/PartialOrd Derivable doc for enum types

Expand Derivable docblock section for `Ord` and `PartialOrd` to cover
`enum` types, in addition to the existing language explaining it for
`struct` types.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 6f35d0417f1..2e691ea4af2 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -380,8 +380,9 @@ impl<T: Ord> Ord for Reverse<T> {
 ///
 /// ## Derivable
 ///
-/// This trait can be used with `#[derive]`. When `derive`d, it will produce a lexicographic
-/// ordering based on the top-to-bottom declaration order of the struct's members.
+/// This trait can be used with `#[derive]`. When `derive`d on structs, it will produce a
+/// lexicographic ordering based on the top-to-bottom declaration order of the struct's members.
+/// When `derive`d on enums, variants are ordered by their top-to-bottom declaration order.
 ///
 /// ## How can I implement `Ord`?
 ///
@@ -513,8 +514,9 @@ impl PartialOrd for Ordering {
 ///
 /// ## Derivable
 ///
-/// This trait can be used with `#[derive]`. When `derive`d, it will produce a lexicographic
-/// ordering based on the top-to-bottom declaration order of the struct's members.
+/// This trait can be used with `#[derive]`. When `derive`d on structs, it will produce a
+/// lexicographic ordering based on the top-to-bottom declaration order of the struct's members.
+/// When `derive`d on enums, variants are ordered by their top-to-bottom declaration order.
 ///
 /// ## How can I implement `PartialOrd`?
 ///