[libcxx] fixes up some [concepts]-related code

* moves `std::copy_constructible` so it comes before
  `std::equality_comparable_with`
* replaces a few uses of `auto`

libcxx/include/concepts

@@ -243,6 +243,14 @@ template<class _Tp>
 concept move_constructible =
   constructible_from<_Tp, _Tp> && convertible_to<_Tp, _Tp>;
 
+// [concept.copyconstructible]
+template<class _Tp>
+concept copy_constructible =
+  move_constructible<_Tp> &&
+  constructible_from<_Tp, _Tp&> && convertible_to<_Tp&, _Tp> &&
+  constructible_from<_Tp, const _Tp&> && convertible_to<const _Tp&, _Tp> &&
+  constructible_from<_Tp, const _Tp> && convertible_to<const _Tp, _Tp>;
+
 // [concept.booleantestable]
 template<class _Tp>
 concept __boolean_testable_impl = convertible_to<_Tp, bool>;
@@ -275,14 +283,6 @@ concept equality_comparable_with =
       const remove_reference_t<_Up>&>> &&
   __weakly_equality_comparable_with<_Tp, _Up>;
 
-// [concept.copyconstructible]
-template<class _Tp>
-concept copy_constructible =
-  move_constructible<_Tp> &&
-  constructible_from<_Tp, _Tp&> && convertible_to<_Tp&, _Tp> &&
-  constructible_from<_Tp, const _Tp&> && convertible_to<const _Tp&, _Tp> &&
-  constructible_from<_Tp, const _Tp> && convertible_to<const _Tp, _Tp>;
-
 // [concept.invocable]
 template<class _Fn, class... _Args>
 concept invocable = requires(_Fn&& __fn, _Args&&... __args) {

libcxx/test/std/concepts/callable/invocable.compile.pass.cpp

@@ -49,15 +49,15 @@ int main(int, char**) {
     NotInvocable(&A::F);
 
     {
-      auto X = A{};
+      A X;
       ModelsInvocable(&A::I, X);
       ModelsInvocable(&A::F, X);
       ModelsInvocable(&A::G, X, 0);
       NotInvocable(&A::G, X);
       NotInvocable(&A::G, 0);
       NotInvocable(&A::H);
 
-      auto const& Y = X;
+      A const& Y = X;
       ModelsInvocable(&A::I, Y);
       ModelsInvocable(&A::F, Y);
       NotInvocable(&A::G, Y, 0);

libcxx/test/std/concepts/callable/regularinvocable.compile.pass.cpp

@@ -48,15 +48,15 @@ int main(int, char**) {
     NotRegularInvocable(&A::F);
 
     {
-      auto X = A{};
+      A X;
       ModelsRegularInvocable(&A::I, X);
       ModelsRegularInvocable(&A::F, X);
       ModelsRegularInvocable(&A::G, X, 0);
       NotRegularInvocable(&A::G, X);
       NotRegularInvocable(&A::G, 0);
       NotRegularInvocable(&A::H);
 
-      auto const& Y = X;
+      A const& Y = X;
       ModelsRegularInvocable(&A::I, Y);
       ModelsRegularInvocable(&A::F, Y);
       NotRegularInvocable(&A::G, Y, 0);

libcxx/test/std/concepts/comparison/types.h

@@ -125,22 +125,22 @@ struct cxx20_friend_eq_operator_with_deleted_ne {
 struct member_three_way_comparable_with_deleted_eq {
   auto operator<=>(member_three_way_comparable_with_deleted_eq const&) const =
       default;
-  auto
+  bool
   operator==(member_three_way_comparable_with_deleted_eq const&) const = delete;
 };
 
 struct member_three_way_comparable_with_deleted_ne {
   auto operator<=>(member_three_way_comparable_with_deleted_ne const&) const =
       default;
-  auto
+  bool
   operator!=(member_three_way_comparable_with_deleted_ne const&) const = delete;
 };
 
 struct friend_three_way_comparable_with_deleted_eq {
   friend auto
   operator<=>(friend_three_way_comparable_with_deleted_eq const&,
               friend_three_way_comparable_with_deleted_eq const&) = default;
-  friend auto
+  friend bool
   operator==(friend_three_way_comparable_with_deleted_eq const&,
              friend_three_way_comparable_with_deleted_eq const&) = delete;
 };
@@ -149,7 +149,7 @@ struct friend_three_way_comparable_with_deleted_ne {
   friend auto
   operator<=>(friend_three_way_comparable_with_deleted_ne const&,
               friend_three_way_comparable_with_deleted_ne const&) = default;
-  friend auto
+  friend bool
   operator!=(friend_three_way_comparable_with_deleted_ne const&,
              friend_three_way_comparable_with_deleted_ne const&) = delete;
 };

libcxx/test/std/concepts/lang/assignable.compile.pass.cpp

@@ -125,7 +125,7 @@ template <typename T1, typename T2>
 constexpr bool CheckAssignableFromRvalues() {
   NeverAssignableFrom<T1, T2>();
 
-  constexpr auto Result = std::assignable_from<T1&, T2>;
+  constexpr bool Result = std::assignable_from<T1&, T2>;
   static_assert(std::assignable_from<T1&, T2&&> == Result);
 
   return Result;
@@ -135,7 +135,7 @@ template <typename T1, typename T2>
 constexpr bool CheckAssignableFromLvalues() {
   NeverAssignableFrom<T1, T2>();
 
-  constexpr auto Result = std::assignable_from<T1&, const T2&>;
+  constexpr bool Result = std::assignable_from<T1&, const T2&>;
   static_assert(std::assignable_from<T1&, T2&> == Result);
   static_assert(std::assignable_from<T1&, const T2&> == Result);
 
@@ -543,8 +543,8 @@ static_assert(!CheckAssignableFromLvaluesAndRvalues<
 
 static_assert(CheckAssignableFromLvaluesAndRvalues<std::vector<int>,
                                                    std::vector<int> >());
-static_assert(!CheckAssignableFromLvaluesAndRvalues<std::vector<int>,
-                                                    std::vector<const int> >());
+static_assert(!CheckAssignableFromLvaluesAndRvalues<std::deque<int>,
+                                                    std::deque<const int> >());
 static_assert(!CheckAssignableFromLvaluesAndRvalues<
               std::vector<int>, std::vector<int, A1<int> > >());
 static_assert(!CheckAssignableFromLvaluesAndRvalues<std::vector<int>,

libcxx/test/std/concepts/lang/common.compile.pass.cpp

@@ -16,7 +16,7 @@
 
 template <class T, class U>
 constexpr bool CheckCommonWith() noexcept {
-  constexpr auto result = std::common_with<T, U>;
+  constexpr bool result = std::common_with<T, U>;
   static_assert(std::common_with<T, U&> == result);
   static_assert(std::common_with<T, const U&> == result);
   static_assert(std::common_with<T, volatile U&> == result);