libstdc++: Implement P2997R1 changes to the indirect invocability concepts

This implements the changes of this C++26 paper as a DR against C++20.

In passing this patch removes the std/ranges/version_c++23.cc test which
is now mostly obsolete after the version.def FTM refactoring, and instead
expands the __cpp_lib_ranges checks in another test so that it verifies
the exact value of the FTM on a per language version basis.

libstdc++-v3/ChangeLog:

	* include/bits/iterator_concepts.h (indirectly_unary_invocable):
	Relax as per P2997R1.
	(indirectly_regular_unary_invocable): Likewise.
	(indirect_unary_predicate): Likewise.
	(indirect_binary_predicate): Likewise.
	(indirect_equivalence_relation): Likewise.
	(indirect_strict_weak_order): Likewise.
	* include/bits/version.def (ranges): Update value for C++26.
	* include/bits/version.h: Regenerate.
	* testsuite/24_iterators/indirect_callable/p2997r1.cc: New test.
	* testsuite/std/ranges/version_c++23.cc: Remove.
	* testsuite/std/ranges/headers/ranges/synopsis.cc: Refine the
	__cpp_lib_ranges checks.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

diff --git a/libstdc++-v3/include/bits/iterator_concepts.h b/libstdc++-v3/include/bits/iterator_concepts.h
index 9306b7bd194cf14e4f04ea6bbc43d5a68c440652..d849ddc32fc261a9627050623d0713004e8c025a 100644 (file)
--- a/libstdc++-v3/include/bits/iterator_concepts.h
+++ b/libstdc++-v3/include/bits/iterator_concepts.h
@@ -724,7 +724,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     concept indirectly_unary_invocable = indirectly_readable<_Iter>
       && copy_constructible<_Fn> && invocable<_Fn&, __indirect_value_t<_Iter>>
       && invocable<_Fn&, iter_reference_t<_Iter>>
-      && invocable<_Fn&, iter_common_reference_t<_Iter>>
       && common_reference_with<invoke_result_t<_Fn&, __indirect_value_t<_Iter>>,
                               invoke_result_t<_Fn&, iter_reference_t<_Iter>>>;
 
@@ -733,15 +732,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       && copy_constructible<_Fn>
       && regular_invocable<_Fn&, __indirect_value_t<_Iter>>
       && regular_invocable<_Fn&, iter_reference_t<_Iter>>
-      && regular_invocable<_Fn&, iter_common_reference_t<_Iter>>
       && common_reference_with<invoke_result_t<_Fn&, __indirect_value_t<_Iter>>,
                               invoke_result_t<_Fn&, iter_reference_t<_Iter>>>;
 
   template<typename _Fn, typename _Iter>
     concept indirect_unary_predicate = indirectly_readable<_Iter>
       && copy_constructible<_Fn> && predicate<_Fn&, __indirect_value_t<_Iter>>
-      && predicate<_Fn&, iter_reference_t<_Iter>>
-      && predicate<_Fn&, iter_common_reference_t<_Iter>>;
+      && predicate<_Fn&, iter_reference_t<_Iter>>;
 
   template<typename _Fn, typename _I1, typename _I2>
     concept indirect_binary_predicate
@@ -750,9 +747,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       && predicate<_Fn&, __indirect_value_t<_I1>, __indirect_value_t<_I2>>
       && predicate<_Fn&, __indirect_value_t<_I1>, iter_reference_t<_I2>>
       && predicate<_Fn&, iter_reference_t<_I1>, __indirect_value_t<_I2>>
-      && predicate<_Fn&, iter_reference_t<_I1>, iter_reference_t<_I2>>
-      && predicate<_Fn&, iter_common_reference_t<_I1>,
-                  iter_common_reference_t<_I2>>;
+      && predicate<_Fn&, iter_reference_t<_I1>, iter_reference_t<_I2>>;
 
   template<typename _Fn, typename _I1, typename _I2 = _I1>
     concept indirect_equivalence_relation
@@ -762,9 +757,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       && equivalence_relation<_Fn&, __indirect_value_t<_I1>, iter_reference_t<_I2>>
       && equivalence_relation<_Fn&, iter_reference_t<_I1>, __indirect_value_t<_I2>>
       && equivalence_relation<_Fn&, iter_reference_t<_I1>,
-                             iter_reference_t<_I2>>
-      && equivalence_relation<_Fn&, iter_common_reference_t<_I1>,
-                             iter_common_reference_t<_I2>>;
+                             iter_reference_t<_I2>>;
 
   template<typename _Fn, typename _I1, typename _I2 = _I1>
     concept indirect_strict_weak_order
@@ -773,9 +766,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       && strict_weak_order<_Fn&, __indirect_value_t<_I1>, __indirect_value_t<_I2>>
       && strict_weak_order<_Fn&, __indirect_value_t<_I1>, iter_reference_t<_I2>>
       && strict_weak_order<_Fn&, iter_reference_t<_I1>, __indirect_value_t<_I2>>
-      && strict_weak_order<_Fn&, iter_reference_t<_I1>, iter_reference_t<_I2>>
-      && strict_weak_order<_Fn&, iter_common_reference_t<_I1>,
-                          iter_common_reference_t<_I2>>;
+      && strict_weak_order<_Fn&, iter_reference_t<_I1>, iter_reference_t<_I2>>;
 
   template<typename _Fn, typename... _Is>
     requires (indirectly_readable<_Is> && ...)

diff --git a/libstdc++-v3/include/bits/version.def b/libstdc++-v3/include/bits/version.def
index ea82c6fa2ca87b46ceca0cafe35ac138b24d8955..bd3af9cba994ae84b705345c50b2628fe79b78bf 100644 (file)
--- a/libstdc++-v3/include/bits/version.def
+++ b/libstdc++-v3/include/bits/version.def
@@ -1071,6 +1071,11 @@ ftms = {
 
 ftms = {
   name = ranges;
+  values = {
+    v = 202406;
+    cxxmin = 26;
+    extra_cond = "__glibcxx_concepts";
+  };
   values = {
     v = 202302;
     cxxmin = 23;

diff --git a/libstdc++-v3/include/bits/version.h b/libstdc++-v3/include/bits/version.h
index 981f0b7caea505f819ca5b4a2efd719e14b2a70f..364e3a05f0e98621870e620e9df20d72e6993259 100644 (file)
--- a/libstdc++-v3/include/bits/version.h
+++ b/libstdc++-v3/include/bits/version.h
@@ -1204,7 +1204,12 @@
 #undef __glibcxx_want_shift
 
 #if !defined(__cpp_lib_ranges)
-# if (__cplusplus >= 202100L) && (__glibcxx_concepts)
+# if (__cplusplus >  202302L) && (__glibcxx_concepts)
+#  define __glibcxx_ranges 202406L
+#  if defined(__glibcxx_want_all) || defined(__glibcxx_want_ranges)
+#   define __cpp_lib_ranges 202406L
+#  endif
+# elif (__cplusplus >= 202100L) && (__glibcxx_concepts)
 #  define __glibcxx_ranges 202302L
 #  if defined(__glibcxx_want_all) || defined(__glibcxx_want_ranges)
 #   define __cpp_lib_ranges 202302L

diff --git a/libstdc++-v3/testsuite/24_iterators/indirect_callable/p2997r1.cc b/libstdc++-v3/testsuite/24_iterators/indirect_callable/p2997r1.cc
new file mode 100644 (file)
index 0000000..6a66b0f
--- /dev/null
+++ b/libstdc++-v3/testsuite/24_iterators/indirect_callable/p2997r1.cc
@@ -0,0 +1,37 @@
+// Test the example from P2997R1 "Removing the common reference requirement
+// from the indirectly invocable concepts".
+// { dg-do compile { target c++20 } }
+
+#include <algorithm>
+#include <ranges>
+
+struct C {
+    auto f() -> void;
+};
+
+struct Iterator {
+    using value_type = C;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category = std::input_iterator_tag;
+
+    auto operator*() const -> C&&;
+    auto operator++() -> Iterator&;
+    auto operator++(int) -> void;
+    auto operator==(Iterator const&) const -> bool;
+};
+
+static_assert(std::input_iterator<Iterator>);
+static_assert(std::same_as<std::iter_value_t<Iterator>, C>);
+static_assert(std::same_as<std::iter_reference_t<Iterator>, C&&>);
+
+struct R {
+    auto begin() -> Iterator;
+    auto end() -> Iterator;
+};
+
+static_assert(std::ranges::range<R>);
+static_assert(std::same_as<std::ranges::range_reference_t<R>, C&&>);
+
+auto f(R r) -> void {
+    std::ranges::for_each(r, [](auto&& c){ c.f(); });
+}

diff --git a/libstdc++-v3/testsuite/std/ranges/headers/ranges/synopsis.cc b/libstdc++-v3/testsuite/std/ranges/headers/ranges/synopsis.cc
index 48f53b63f4030a554c0e207ad74a996f36bc85c0..d359039da3f4cb065cf3f2367b3ac25d99d12c65 100644 (file)
--- a/libstdc++-v3/testsuite/std/ranges/headers/ranges/synopsis.cc
+++ b/libstdc++-v3/testsuite/std/ranges/headers/ranges/synopsis.cc
@@ -22,7 +22,11 @@
 
 #ifndef __cpp_lib_ranges
 # error "Feature test macro for ranges is missing in <ranges>"
-#elif __cpp_lib_ranges < 201911L
+#elif __cplusplus > 202302L && __cpp_lib_ranges != 202406L
+# error "Feature test macro for ranges has wrong value in <ranges>"
+#elif __cplusplus == 202302L && __cpp_lib_ranges != 202302L
+# error "Feature test macro for ranges has wrong value in <ranges>"
+#elif __cplusplus == 202002L && __cpp_lib_ranges != 202110L
 # error "Feature test macro for ranges has wrong value in <ranges>"
 #endif
 

diff --git a/libstdc++-v3/testsuite/std/ranges/version_c++23.cc b/libstdc++-v3/testsuite/std/ranges/version_c++23.cc
deleted file mode 100644 (file)
index 0187115..0000000
--- a/libstdc++-v3/testsuite/std/ranges/version_c++23.cc
+++ /dev/null
@@ -1,70 +0,0 @@
-// { dg-do preprocess { target c++23 } }
-// { dg-add-options no_pch }
-
-#include <version>
-
-#if __STDC_HOSTED__
-# if __cpp_lib_ranges != 202302L
-#  error "Feature-test macro __cpp_lib_ranges has wrong value in <version>"
-# endif
-#endif
-
-#if __cpp_lib_ranges_zip != 202110L
-# error "Feature-test macro __cpp_lib_ranges_zip has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_chunk != 202202L
-# error "Feature-test macro __cpp_lib_ranges_chunk has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_slide != 202202L
-# error "Feature-test macro __cpp_lib_ranges_slide has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_chunk_by != 202202L
-# error "Feature-test macro __cpp_lib_ranges_chunk_by has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_join_with != 202202L
-# error "Feature-test macro __cpp_lib_ranges_join_with has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_repeat != 202207L
-# error "Feature-test macro __cpp_lib_ranges_repeat has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_stride != 202207L
-# error "Feature-test macro __cpp_lib_ranges_stride has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_cartesian_product != 202207L
-# error "Feature-test macro __cpp_lib_ranges_cartesian_product has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_as_rvalue != 202207L
-# error "Feature-test macro __cpp_lib_ranges_as_rvalue has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_as_const != 202311L
-# error "Feature-test macro __cpp_lib_ranges_as_const has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_enumerate != 202302L
-# error "Feature-test macro __cpp_lib_ranges_enumerate has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_contains != 202207L
-# error "Feature-test macro __cpp_lib_ranges_contains has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_iota != 202202L
-# error "Feature-test macro __cpp_lib_ranges_iota has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_find_last != 202207L
-# error "Feature-test macro __cpp_lib_ranges_find_last has wrong value in <version>"
-#endif
-
-#if __cpp_lib_ranges_fold != 202207L
-# error "Feature-test macro __cpp_lib_ranges_fold has wrong value in <version>"
-#endif