CI fixes.

Author: mordante

libcxx/include/__iterator/bounded_iter.h

@@ -202,7 +202,7 @@ struct __bounded_iter {
   operator==(__bounded_iter const& __x, __bounded_iter const& __y) _NOEXCEPT {
     return __x.__current_ == __y.__current_;
   }
-#if _LIBCPP_STD_VER <= 17
+
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR friend bool
   operator!=(__bounded_iter const& __x, __bounded_iter const& __y) _NOEXCEPT {
     return __x.__current_ != __y.__current_;
@@ -224,14 +224,19 @@ struct __bounded_iter {
     return __x.__current_ >= __y.__current_;
   }
 
-#else // _LIBCPP_STD_VER <= 17
-
+#if _LIBCPP_STD_VER >= 20
+  // It is not required that the underlying iterator supports operator<=>.
+  // Therefore this operator is only conditionally provided, which requires a
+  // templated function.
+  template <class _Tp = void>
+    requires requires(_Iterator const& __i) {
+      { __i <=> __i } -> same_as<strong_ordering>;
+    }
   _LIBCPP_HIDE_FROM_ABI constexpr friend strong_ordering
   operator<=>(__bounded_iter const& __x, __bounded_iter const& __y) noexcept {
     return __x.__current_ <=> __y.__current_;
   }
-
-#endif // _LIBCPP_STD_VER <= 17
+#endif // _LIBCPP_STD_VER >= 20
 
 private:
   template <class>

libcxx/test/libcxx/iterators/bounded_iter/comparison.pass.cpp

@@ -11,6 +11,7 @@
 //
 // Comparison operators
 
+#include <concepts>
 #include <__iterator/bounded_iter.h>
 
 #include "test_iterators.h"
@@ -59,6 +60,16 @@ TEST_CONSTEXPR_CXX14 bool tests() {
     assert(iter1 >= iter1);
   }
 
+#if TEST_STD_VER >= 20
+  if constexpr (requires(std::__bounded_iter<Iter> const iter) {
+                  { iter <=> iter } -> std::same_as<std::strong_ordering>;
+                }) {
+    // P1614
+    std::same_as<std::strong_ordering> decltype(auto) r1 = iter1 <=> iter2;
+    assert(r1 == std::strong_ordering::less);
+  }
+#endif
+
   return true;
 }
 
@@ -69,8 +80,11 @@ int main(int, char**) {
 #endif
 
 #if TEST_STD_VER > 17
-  tests<contiguous_iterator<int*> >();
-  static_assert(tests<contiguous_iterator<int*> >(), "");
+  tests<contiguous_iterator<int*>>();
+  static_assert(tests<contiguous_iterator<int*>>());
+
+  tests<three_way_contiguous_iterator<int*>>();
+  static_assert(tests<three_way_contiguous_iterator<int*>>());
 #endif
 
   return 0;

libcxx/test/std/containers/views/views.span/span.iterators/iterator.pass.cpp

@@ -12,8 +12,9 @@
 
 // class iterator
 
-#include <span>
 #include <cassert>
+#include <concepts>
+#include <span>
 #include <string>
 #include <version> // __cpp_lib_ranges_as_const is not defined in span.
 

libcxx/test/std/strings/string.view/string.view.iterators/iterators.pass.cpp

@@ -12,9 +12,10 @@
 
 // class iterator
 
-#include <string_view>
 #include <cassert>
+#include <concepts>
 #include <iterator>
+#include <string_view>
 
 #include "test_macros.h"
 #include "make_string.h"

libcxx/test/support/test_iterators.h

@@ -389,6 +389,8 @@ class contiguous_iterator
     friend TEST_CONSTEXPR bool operator> (const contiguous_iterator& x, const contiguous_iterator& y) {return x.it_ >  y.it_;}
     friend TEST_CONSTEXPR bool operator>=(const contiguous_iterator& x, const contiguous_iterator& y) {return x.it_ >= y.it_;}
 
+    // Note no operator<=>, use three_way_contiguous_iterator for testing operator<=>
+
     friend TEST_CONSTEXPR It base(const contiguous_iterator& i) { return i.it_; }
 
     template <class T>