From c8bc4b7a55606ae6d7b7af7c116c8188762b0871 Mon Sep 17 00:00:00 2001
From: Stein Somers <git@steinsomers.be>
Date: Fri, 10 Dec 2021 15:18:54 +0100
Subject: [PATCH 1/2] BTree: rename compile-time assertions to match
 library/alloc/tests

---
 library/alloc/src/collections/btree/map/tests.rs | 6 +++---
 library/alloc/src/collections/btree/set/tests.rs | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/library/alloc/src/collections/btree/map/tests.rs b/library/alloc/src/collections/btree/map/tests.rs
index 17389657afb92..c95aeeaa60558 100644
--- a/library/alloc/src/collections/btree/map/tests.rs
+++ b/library/alloc/src/collections/btree/map/tests.rs
@@ -1556,7 +1556,7 @@ fn test_clone_from() {
 }
 
 #[allow(dead_code)]
-fn test_variance() {
+fn assert_covariance() {
     fn map_key<'new>(v: BTreeMap<&'static str, ()>) -> BTreeMap<&'new str, ()> {
         v
     }
@@ -1615,7 +1615,7 @@ fn test_variance() {
 }
 
 #[allow(dead_code)]
-fn test_sync() {
+fn assert_sync() {
     fn map<T: Sync>(v: &BTreeMap<T, T>) -> impl Sync + '_ {
         v
     }
@@ -1684,7 +1684,7 @@ fn test_sync() {
 }
 
 #[allow(dead_code)]
-fn test_send() {
+fn assert_send() {
     fn map<T: Send>(v: BTreeMap<T, T>) -> impl Send {
         v
     }
diff --git a/library/alloc/src/collections/btree/set/tests.rs b/library/alloc/src/collections/btree/set/tests.rs
index 2fc17a7c8603f..9a5bfb3d95813 100644
--- a/library/alloc/src/collections/btree/set/tests.rs
+++ b/library/alloc/src/collections/btree/set/tests.rs
@@ -513,7 +513,7 @@ fn test_recovery() {
 }
 
 #[allow(dead_code)]
-fn test_variance() {
+fn assert_covariance() {
     fn set<'new>(v: BTreeSet<&'static str>) -> BTreeSet<&'new str> {
         v
     }
@@ -530,7 +530,7 @@ fn test_variance() {
 }
 
 #[allow(dead_code)]
-fn test_sync() {
+fn assert_sync() {
     fn set<T: Sync>(v: &BTreeSet<T>) -> impl Sync + '_ {
         v
     }
@@ -569,7 +569,7 @@ fn test_sync() {
 }
 
 #[allow(dead_code)]
-fn test_send() {
+fn assert_send() {
     fn set<T: Send>(v: BTreeSet<T>) -> impl Send {
         v
     }

From cc35a11a393c3fca47a3b80db48c39c416f20bf6 Mon Sep 17 00:00:00 2001
From: Stein Somers <git@steinsomers.be>
Date: Fri, 10 Dec 2021 15:18:54 +0100
Subject: [PATCH 2/2] BTree: assert presence of derived functions

---
 .../alloc/src/collections/btree/set/tests.rs  | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/library/alloc/src/collections/btree/set/tests.rs b/library/alloc/src/collections/btree/set/tests.rs
index 9a5bfb3d95813..7390ff5a59c8c 100644
--- a/library/alloc/src/collections/btree/set/tests.rs
+++ b/library/alloc/src/collections/btree/set/tests.rs
@@ -3,6 +3,7 @@ use super::super::testing::rng::DeterministicRng;
 use super::*;
 use crate::vec::Vec;
 use std::cmp::Ordering;
+use std::hash::{Hash, Hasher};
 use std::iter::FromIterator;
 use std::panic::{catch_unwind, AssertUnwindSafe};
 
@@ -607,6 +608,37 @@ fn assert_send() {
     }
 }
 
+#[allow(dead_code)]
+// Check that the member-like functions conditionally provided by #[derive()]
+// are not overriden by genuine member functions with a different signature.
+fn assert_derives() {
+    fn hash<T: Hash, H: Hasher>(v: BTreeSet<T>, state: &mut H) {
+        v.hash(state);
+        // Tested much more thoroughly outside the crate in btree_set_hash.rs
+    }
+    fn eq<T: PartialEq>(v: BTreeSet<T>) {
+        let _ = v.eq(&v);
+    }
+    fn ne<T: PartialEq>(v: BTreeSet<T>) {
+        let _ = v.ne(&v);
+    }
+    fn cmp<T: Ord>(v: BTreeSet<T>) {
+        let _ = v.cmp(&v);
+    }
+    fn min<T: Ord>(v: BTreeSet<T>, w: BTreeSet<T>) {
+        let _ = v.min(w);
+    }
+    fn max<T: Ord>(v: BTreeSet<T>, w: BTreeSet<T>) {
+        let _ = v.max(w);
+    }
+    fn clamp<T: Ord>(v: BTreeSet<T>, w: BTreeSet<T>, x: BTreeSet<T>) {
+        let _ = v.clamp(w, x);
+    }
+    fn partial_cmp<T: PartialOrd>(v: &BTreeSet<T>) {
+        let _ = v.partial_cmp(&v);
+    }
+}
+
 #[test]
 fn test_ord_absence() {
     fn set<K>(mut set: BTreeSet<K>) {