libstdc++: Revert final/non-addressable changes to ranges CPOs

In r12-1489-g8b93548778a487f31f21e0c6afe7e0bde9711fc4 I made the [range.access] CPO types final and non-addressable. Tim Song pointed out this is wrong. Only the [range.iter.ops] functions should be final and non-addressable. Revert the changes to the [range.access] objects. Signed-off-by: Jonathan Wakely <jwakely@redhat.com> libstdc++-v3/ChangeLog: * include/bits/ranges_base.h (ranges::begin, ranges::end) (ranges::cbegin, ranges::cend, ranges::rbeing, ranges::rend) (ranges::crbegin, ranges::crend, ranges::size, ranges::ssize) (ranges::empty, ranges::data, ranges::cdata): Remove final keywords and deleted operator& overloads. * testsuite/24_iterators/customization_points/iter_move.cc: Use new is_customization_point_object function. * testsuite/24_iterators/customization_points/iter_swap.cc: Likewise. * testsuite/std/concepts/concepts.lang/concept.swappable/swap.cc: Likewise. * testsuite/std/ranges/access/begin.cc: Likewise. * testsuite/std/ranges/access/cbegin.cc: Likewise. * testsuite/std/ranges/access/cdata.cc: Likewise. * testsuite/std/ranges/access/cend.cc: Likewise. * testsuite/std/ranges/access/crbegin.cc: Likewise. * testsuite/std/ranges/access/crend.cc: Likewise. * testsuite/std/ranges/access/data.cc: Likewise. * testsuite/std/ranges/access/empty.cc: Likewise. * testsuite/std/ranges/access/end.cc: Likewise. * testsuite/std/ranges/access/rbegin.cc: Likewise. * testsuite/std/ranges/access/rend.cc: Likewise. * testsuite/std/ranges/access/size.cc: Likewise. * testsuite/std/ranges/access/ssize.cc: Likewise. * testsuite/util/testsuite_iterators.h (is_customization_point_object): New function.
2021-06-16 12:34:52 +01:00 · 2021-06-16 12:34:52 +01:00 · b9e35ee6d6
commit b9e35ee6d6
parent dbfc149b63
18 changed files with 68 additions and 38 deletions
--- a/libstdc++-v3/include/bits/ranges_base.h
+++ b/libstdc++-v3/include/bits/ranges_base.h
@ -91,7 +91,7 @@ namespace ranges
    using std::ranges::__detail::__maybe_borrowed_range;
    using std::__detail::__range_iter_t;

-    struct _Begin final
+    struct _Begin
    {
    private:
      template<typename _Tp>
@ -106,8 +106,6 @@ namespace ranges
 	    return noexcept(__decay_copy(begin(std::declval<_Tp&>())));
 	}

-      void operator&() const = delete;
-
    public:
      template<__maybe_borrowed_range _Tp>
 	requires is_array_v<remove_reference_t<_Tp>> || __member_begin<_Tp>
@ -144,7 +142,7 @@ namespace ranges
 	  { __decay_copy(end(__t)) } -> sentinel_for<__range_iter_t<_Tp>>;
 	};

-    struct _End final
+    struct _End
    {
    private:
      template<typename _Tp>
@ -159,8 +157,6 @@ namespace ranges
 	    return noexcept(__decay_copy(end(std::declval<_Tp&>())));
 	}

-      void operator&() const = delete;
-
    public:
      template<__maybe_borrowed_range _Tp>
 	requires is_bounded_array_v<remove_reference_t<_Tp>>
@ -193,7 +189,7 @@ namespace ranges
 	  return static_cast<const _Tp&&>(__t);
      }

-    struct _CBegin final
+    struct _CBegin
    {
      template<typename _Tp>
 	constexpr auto
@ -203,8 +199,6 @@ namespace ranges
 	{
 	  return _Begin{}(__cust_access::__as_const<_Tp>(__e));
 	}
-
-      void operator&() const = delete;
    };

    struct _CEnd final
@ -217,8 +211,6 @@ namespace ranges
 	{
 	  return _End{}(__cust_access::__as_const<_Tp>(__e));
 	}
-
-      void operator&() const = delete;
    };

    template<typename _Tp>
@ -244,7 +236,7 @@ namespace ranges
 	  { _End{}(__t) } -> same_as<decltype(_Begin{}(__t))>;
 	};

-    struct _RBegin final
+    struct _RBegin
    {
    private:
      template<typename _Tp>
@ -268,8 +260,6 @@ namespace ranges
 	    }
 	}

-      void operator&() const = delete;
-
    public:
      template<__maybe_borrowed_range _Tp>
 	requires __member_rbegin<_Tp> || __adl_rbegin<_Tp> || __reversable<_Tp>
@ -304,7 +294,7 @@ namespace ranges
 	    -> sentinel_for<decltype(_RBegin{}(std::forward<_Tp>(__t)))>;
 	};

-    struct _REnd final
+    struct _REnd
    {
    private:
      template<typename _Tp>
@ -328,8 +318,6 @@ namespace ranges
 	    }
 	}

-      void operator&() const = delete;
-
    public:
      template<__maybe_borrowed_range _Tp>
 	requires __member_rend<_Tp> || __adl_rend<_Tp> || __reversable<_Tp>
@ -346,7 +334,7 @@ namespace ranges
 	}
    };

-    struct _CRBegin final
+    struct _CRBegin
    {
      template<typename _Tp>
 	constexpr auto
@ -356,11 +344,9 @@ namespace ranges
 	{
 	  return _RBegin{}(__cust_access::__as_const<_Tp>(__e));
 	}
-
-      void operator&() const = delete;
    };

-    struct _CREnd final
+    struct _CREnd
    {
      template<typename _Tp>
 	constexpr auto
@ -370,8 +356,6 @@ namespace ranges
 	{
 	  return _REnd{}(__cust_access::__as_const<_Tp>(__e));
 	}
-
-      void operator&() const = delete;
    };

    template<typename _Tp>
@ -402,7 +386,7 @@ namespace ranges
 	  __detail::__to_unsigned_like(_End{}(__t) - _Begin{}(__t));
 	};

-    struct _Size final
+    struct _Size
    {
    private:
      template<typename _Tp>
@ -420,8 +404,6 @@ namespace ranges
 			    - _Begin{}(std::declval<_Tp&>()));
 	}

-      void operator&() const = delete;
-
    public:
      template<typename _Tp>
 	requires is_bounded_array_v<remove_reference_t<_Tp>>
@ -440,7 +422,7 @@ namespace ranges
 	}
    };

-    struct _SSize final
+    struct _SSize
    {
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 3403. Domain of ranges::ssize(E) doesn't match ranges::size(E)
@ -469,8 +451,6 @@ namespace ranges
 	  else // Must be one of __max_diff_type or __max_size_type.
 	    return __detail::__max_diff_type(__size);
 	}
-
-      void operator&() const = delete;
    };

    template<typename _Tp>
@ -487,7 +467,7 @@ namespace ranges
 	  bool(_Begin{}(__t) == _End{}(__t));
 	};

-    struct _Empty final
+    struct _Empty
    {
    private:
      template<typename _Tp>
@ -503,8 +483,6 @@ namespace ranges
 		== _End{}(std::declval<_Tp&>())));
 	}

-      void operator&() const = delete;
-
    public:
      template<typename _Tp>
 	requires __member_empty<_Tp> || __size0_empty<_Tp>
@ -534,7 +512,7 @@ namespace ranges
    template<typename _Tp>
      concept __begin_data = contiguous_iterator<__range_iter_t<_Tp>>;

-    struct _Data final
+    struct _Data
    {
    private:
      template<typename _Tp>
@ -547,8 +525,6 @@ namespace ranges
 	    return noexcept(_Begin{}(std::declval<_Tp&>()));
 	}

-      void operator&() const = delete;
-
    public:
      template<__maybe_borrowed_range _Tp>
 	requires __member_data<_Tp> || __begin_data<_Tp>
@ -562,7 +538,7 @@ namespace ranges
 	}
    };

-    struct _CData final
+    struct _CData
    {
      template<typename _Tp>
 	constexpr auto
@ -572,8 +548,6 @@ namespace ranges
 	{
 	  return _Data{}(__cust_access::__as_const<_Tp>(__e));
 	}
-
-      void operator&() const = delete;
    };

  } // namespace __cust_access
--- a/libstdc++-v3/testsuite/24_iterators/customization_points/iter_move.cc
+++ b/libstdc++-v3/testsuite/24_iterators/customization_points/iter_move.cc
@ -20,6 +20,9 @@

 #include <iterator>
 #include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+static_assert(__gnu_test::is_customization_point_object(std::ranges::iter_move));

 struct X
 {
--- a/libstdc++-v3/testsuite/24_iterators/customization_points/iter_swap.cc
+++ b/libstdc++-v3/testsuite/24_iterators/customization_points/iter_swap.cc
@ -20,6 +20,9 @@

 #include <iterator>
 #include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+static_assert(__gnu_test::is_customization_point_object(std::ranges::iter_swap));

 struct X
 {
--- a/libstdc++-v3/testsuite/std/concepts/concepts.lang/concept.swappable/swap.cc
+++ b/libstdc++-v3/testsuite/std/concepts/concepts.lang/concept.swappable/swap.cc
@ -19,6 +19,10 @@
 // { dg-do compile { target c++2a } }

 #include <concepts>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+static_assert(__gnu_test::is_customization_point_object(std::ranges::swap));

 namespace nu
 {
--- a/libstdc++-v3/testsuite/std/ranges/access/begin.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/begin.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::begin));
+
 using std::same_as;

 void
--- a/libstdc++-v3/testsuite/std/ranges/access/cbegin.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/cbegin.cc
@ -20,6 +20,10 @@

 #include <ranges>
 #include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+static_assert(__gnu_test::is_customization_point_object(std::ranges::cbegin));
+
 using std::same_as;

 void
--- a/libstdc++-v3/testsuite/std/ranges/access/cdata.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/cdata.cc
@ -20,6 +20,9 @@

 #include <ranges>
 #include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+static_assert(__gnu_test::is_customization_point_object(std::ranges::cdata));

 template<typename T>
  concept has_cdata
--- a/libstdc++-v3/testsuite/std/ranges/access/cend.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/cend.cc
@ -20,6 +20,9 @@

 #include <ranges>
 #include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+static_assert(__gnu_test::is_customization_point_object(std::ranges::cend));

 using std::same_as;

--- a/libstdc++-v3/testsuite/std/ranges/access/crbegin.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/crbegin.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::crbegin));
+
 struct R1
 {
  int i = 0;
--- a/libstdc++-v3/testsuite/std/ranges/access/crend.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/crend.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::crend));
+
 struct R1
 {
  int i = 0;
--- a/libstdc++-v3/testsuite/std/ranges/access/data.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/data.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::data));
+
 template<typename T>
  concept has_data
    = requires (T&& t) { std::ranges::data(std::forward<T>(t)); };
--- a/libstdc++-v3/testsuite/std/ranges/access/empty.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/empty.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::empty));
+
 using std::same_as;

 void
--- a/libstdc++-v3/testsuite/std/ranges/access/end.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/end.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::end));
+
 using std::same_as;

 void
--- a/libstdc++-v3/testsuite/std/ranges/access/rbegin.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/rbegin.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::rbegin));
+
 struct R1
 {
  int i = 0;
--- a/libstdc++-v3/testsuite/std/ranges/access/rend.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/rend.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::rend));
+
 struct R1
 {
  int i = 0;
--- a/libstdc++-v3/testsuite/std/ranges/access/size.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/size.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::size));
+
 void
 test01()
 {
--- a/libstdc++-v3/testsuite/std/ranges/access/ssize.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/ssize.cc
@ -22,6 +22,8 @@
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>

+static_assert(__gnu_test::is_customization_point_object(std::ranges::ssize));
+
 using std::ptrdiff_t;

 void
--- a/libstdc++-v3/testsuite/util/testsuite_iterators.h
+++ b/libstdc++-v3/testsuite/util/testsuite_iterators.h
@ -894,6 +894,22 @@ namespace __gnu_test
 // This is also true for test_container, although only when it has forward
 // iterators (because output_iterator_wrapper and input_iterator_wrapper are
 // not default constructible so do not model std::input_or_output_iterator).
+
+
+  // Test for basic properties of C++20 16.3.3.6 [customization.point.object].
+  template<typename T>
+    constexpr bool
+    is_customization_point_object(T& obj) noexcept
+    {
+      // A [CPO] is a function object with a literal class type.
+      static_assert( std::is_class_v<T> || std::is_union_v<T> );
+      static_assert( __is_literal_type(T) );
+      // The type of a [CPO], ignoring cv-qualifiers, shall model semiregular.
+      static_assert( std::semiregular<std::remove_cv_t<T>> );
+
+      return true;
+    }
+
 #endif // C++20
 } // namespace __gnu_test
 #endif // _TESTSUITE_ITERATORS