Adding upstream version 1.65.0+dfsg1.upstream/1.65.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/src/tools/clippy/src/docs/derive_ord_xor_partial_ord.txt b/src/tools/clippy/src/docs/derive_ord_xor_partial_ord.txt
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+++ b/src/tools/clippy/src/docs/derive_ord_xor_partial_ord.txt
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+### What it does
+Checks for deriving `Ord` but implementing `PartialOrd`
+explicitly or vice versa.
+
+### Why is this bad?
+The implementation of these traits must agree (for
+example for use with `sort`) so it’s probably a bad idea to use a
+default-generated `Ord` implementation with an explicitly defined
+`PartialOrd`. In particular, the following must hold for any type
+implementing `Ord`:
+
+```
+k1.cmp(&k2) == k1.partial_cmp(&k2).unwrap()
+```
+
+### Example
+```
+#[derive(Ord, PartialEq, Eq)]
+struct Foo;
+
+impl PartialOrd for Foo {
+    ...
+}
+```
+Use instead:
+```
+#[derive(PartialEq, Eq)]
+struct Foo;
+
+impl PartialOrd for Foo {
+    fn partial_cmp(&self, other: &Foo) -> Option<Ordering> {
+       Some(self.cmp(other))
+    }
+}
+
+impl Ord for Foo {
+    ...
+}
+```
+or, if you don't need a custom ordering:
+```
+#[derive(Ord, PartialOrd, PartialEq, Eq)]
+struct Foo;
+```
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