[libc++] P2602R2 Poison Pills are Too Toxic #74534

JMazurkiewicz · 2023-12-05T23:00:44Z

Implements P2602R2 Poison Pills are Too Toxic as a DR in C++20 mode.

llvmbot · 2023-12-05T23:01:15Z

@llvm/pr-subscribers-libcxx

Author: Jakub Mazurkiewicz (JMazurkiewicz)

Changes

This PR contains P2602R2 implemented as a DR in C++20 mode.

Patch is 43.74 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/74534.diff

30 Files Affected:

(modified) libcxx/docs/FeatureTestMacroTable.rst (+1-1)
(modified) libcxx/docs/Status/Cxx23Papers.csv (+1-1)
(modified) libcxx/include/__compare/partial_order.h (+2)
(modified) libcxx/include/__compare/strong_order.h (+2)
(modified) libcxx/include/__compare/weak_order.h (+2)
(modified) libcxx/include/__iterator/iter_move.h (+1-1)
(modified) libcxx/include/__ranges/access.h (+2-4)
(modified) libcxx/include/__ranges/rbegin.h (+1-2)
(modified) libcxx/include/__ranges/rend.h (+1-2)
(modified) libcxx/include/__ranges/size.h (+1-2)
(modified) libcxx/include/version (+2-2)
(modified) libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.pass.cpp (+11)
(modified) libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.swap/iter_swap.pass.cpp (+6)
(added) libcxx/test/std/language.support/cmp/cmp.alg/ordinary_unqualified_lookup_helpers.h (+33)
(modified) libcxx/test/std/language.support/cmp/cmp.alg/partial_order.pass.cpp (+9)
(modified) libcxx/test/std/language.support/cmp/cmp.alg/strong_order.pass.cpp (+9)
(modified) libcxx/test/std/language.support/cmp/cmp.alg/weak_order.pass.cpp (+9)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/algorithm.version.compile.pass.cpp (+7-7)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/functional.version.compile.pass.cpp (+7-7)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/iterator.version.compile.pass.cpp (+7-7)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/memory.version.compile.pass.cpp (+7-7)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/ranges.version.compile.pass.cpp (+7-7)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp (+7-7)
(modified) libcxx/test/std/ranges/range.access/begin.pass.cpp (+13-5)
(modified) libcxx/test/std/ranges/range.access/end.pass.cpp (+14-6)
(added) libcxx/test/std/ranges/range.access/ordinary_unqualified_lookup_helpers.h (+25)
(modified) libcxx/test/std/ranges/range.access/rbegin.pass.cpp (+13-5)
(modified) libcxx/test/std/ranges/range.access/rend.pass.cpp (+14-6)
(modified) libcxx/test/std/ranges/range.access/size.pass.cpp (+8-1)
(modified) libcxx/utils/generate_feature_test_macro_components.py (+1-1)

diff --git a/libcxx/docs/FeatureTestMacroTable.rst b/libcxx/docs/FeatureTestMacroTable.rst
index d09f65b7cadc0..f4788aa574788 100644
--- a/libcxx/docs/FeatureTestMacroTable.rst
+++ b/libcxx/docs/FeatureTestMacroTable.rst
@@ -266,7 +266,7 @@ Status
     --------------------------------------------------- -----------------
     ``__cpp_lib_polymorphic_allocator``                 ``201902L``
     --------------------------------------------------- -----------------
-    ``__cpp_lib_ranges``                                ``202207L``
+    ``__cpp_lib_ranges``                                ``202211L``
     --------------------------------------------------- -----------------
     ``__cpp_lib_remove_cvref``                          ``201711L``
     --------------------------------------------------- -----------------
diff --git a/libcxx/docs/Status/Cxx23Papers.csv b/libcxx/docs/Status/Cxx23Papers.csv
index e03cbff2a08bb..7dc6f36ba1e63 100644
--- a/libcxx/docs/Status/Cxx23Papers.csv
+++ b/libcxx/docs/Status/Cxx23Papers.csv
@@ -100,7 +100,7 @@
 "`P2396R1 <https://wg21.link/P2396R1>`__","LWG", "Concurrency TS 2 fixes ", "November 2022","","","|concurrency TS|"
 "`P2505R5 <https://wg21.link/P2505R5>`__","LWG", "Monadic Functions for ``std::expected``", "November 2022","|Complete|","17.0",""
 "`P2539R4 <https://wg21.link/P2539R4>`__","LWG", "Should the output of ``std::print`` to a terminal be synchronized with the underlying stream?", "November 2022","|In Progress|","","|format|"
-"`P2602R2 <https://wg21.link/P2602R2>`__","LWG", "Poison Pills are Too Toxic", "November 2022","","","|ranges|"
+"`P2602R2 <https://wg21.link/P2602R2>`__","LWG", "Poison Pills are Too Toxic", "November 2022","|Complete|","18.0","|ranges|"
 "`P2708R1 <https://wg21.link/P2708R1>`__","LWG", "No Further Fundamentals TSes", "November 2022","|Nothing to do|","",""
 "","","","","","",""
 "`P0290R4 <https://wg21.link/P0290R4>`__","LWG", "``apply()`` for ``synchronized_value<T>``","February 2023","","","|concurrency TS|"
diff --git a/libcxx/include/__compare/partial_order.h b/libcxx/include/__compare/partial_order.h
index 36a11dfaa2881..b422bdd4ef841 100644
--- a/libcxx/include/__compare/partial_order.h
+++ b/libcxx/include/__compare/partial_order.h
@@ -28,6 +28,8 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 // [cmp.alg]
 namespace __partial_order {
+    void partial_order() = delete;
+
     struct __fn {
     // NOLINTBEGIN(libcpp-robust-against-adl) partial_order should use ADL, but only here
         template<class _Tp, class _Up>
diff --git a/libcxx/include/__compare/strong_order.h b/libcxx/include/__compare/strong_order.h
index cbfcf7316de9e..ba59cb51b86d9 100644
--- a/libcxx/include/__compare/strong_order.h
+++ b/libcxx/include/__compare/strong_order.h
@@ -34,6 +34,8 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 // [cmp.alg]
 namespace __strong_order {
+    void strong_order() = delete;
+
     struct __fn {
     // NOLINTBEGIN(libcpp-robust-against-adl) strong_order should use ADL, but only here
         template<class _Tp, class _Up>
diff --git a/libcxx/include/__compare/weak_order.h b/libcxx/include/__compare/weak_order.h
index e6a42ac4c9235..8d7f939092303 100644
--- a/libcxx/include/__compare/weak_order.h
+++ b/libcxx/include/__compare/weak_order.h
@@ -28,6 +28,8 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 // [cmp.alg]
 namespace __weak_order {
+    void weak_order() = delete;
+
     struct __fn {
     // NOLINTBEGIN(libcpp-robust-against-adl) weak_order should use ADL, but only here
         template<class _Tp, class _Up>
diff --git a/libcxx/include/__iterator/iter_move.h b/libcxx/include/__iterator/iter_move.h
index d9ff90bf65456..79dcac8f50b9f 100644
--- a/libcxx/include/__iterator/iter_move.h
+++ b/libcxx/include/__iterator/iter_move.h
@@ -35,7 +35,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 namespace ranges {
 namespace __iter_move {
 
-void iter_move();
+void iter_move() = delete;
 
 template <class _Tp>
 concept __unqualified_iter_move =
diff --git a/libcxx/include/__ranges/access.h b/libcxx/include/__ranges/access.h
index 502bd5e951c4a..01bf8cc2f544f 100644
--- a/libcxx/include/__ranges/access.h
+++ b/libcxx/include/__ranges/access.h
@@ -49,8 +49,7 @@ namespace __begin {
       { _LIBCPP_AUTO_CAST(__t.begin()) } -> input_or_output_iterator;
     };
 
-  void begin(auto&) = delete;
-  void begin(const auto&) = delete;
+  void begin() = delete;
 
   template <class _Tp>
   concept __unqualified_begin =
@@ -121,8 +120,7 @@ namespace __end {
       { _LIBCPP_AUTO_CAST(__t.end()) } -> sentinel_for<iterator_t<_Tp>>;
     };
 
-  void end(auto&) = delete;
-  void end(const auto&) = delete;
+  void end() = delete;
 
   template <class _Tp>
   concept __unqualified_end =
diff --git a/libcxx/include/__ranges/rbegin.h b/libcxx/include/__ranges/rbegin.h
index 1ceb1116d695f..8fd17a3c016a2 100644
--- a/libcxx/include/__ranges/rbegin.h
+++ b/libcxx/include/__ranges/rbegin.h
@@ -43,8 +43,7 @@ concept __member_rbegin =
     { _LIBCPP_AUTO_CAST(__t.rbegin()) } -> input_or_output_iterator;
   };
 
-void rbegin(auto&) = delete;
-void rbegin(const auto&) = delete;
+void rbegin() = delete;
 
 template <class _Tp>
 concept __unqualified_rbegin =
diff --git a/libcxx/include/__ranges/rend.h b/libcxx/include/__ranges/rend.h
index 7ee574ccfa674..1f482963ac749 100644
--- a/libcxx/include/__ranges/rend.h
+++ b/libcxx/include/__ranges/rend.h
@@ -45,8 +45,7 @@ concept __member_rend =
     { _LIBCPP_AUTO_CAST(__t.rend()) } -> sentinel_for<decltype(ranges::rbegin(__t))>;
   };
 
-void rend(auto&) = delete;
-void rend(const auto&) = delete;
+void rend() = delete;
 
 template <class _Tp>
 concept __unqualified_rend =
diff --git a/libcxx/include/__ranges/size.h b/libcxx/include/__ranges/size.h
index f22dd1ff7b79f..0ed939e0bd4f9 100644
--- a/libcxx/include/__ranges/size.h
+++ b/libcxx/include/__ranges/size.h
@@ -41,8 +41,7 @@ namespace ranges {
 
 namespace ranges {
 namespace __size {
-void size(auto&) = delete;
-void size(const auto&) = delete;
+void size() = delete;
 
 template <class _Tp>
 concept __size_enabled = !disable_sized_range<remove_cvref_t<_Tp>>;
diff --git a/libcxx/include/version b/libcxx/include/version
index e84790b888d33..71937c3a3d1c2 100644
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -164,7 +164,7 @@ __cpp_lib_parallel_algorithm                            201603L <algorithm> <num
 __cpp_lib_polymorphic_allocator                         201902L <memory_resource>
 __cpp_lib_print                                         202207L <ostream> <print>
 __cpp_lib_quoted_string_io                              201304L <iomanip>
-__cpp_lib_ranges                                        202207L <algorithm> <functional> <iterator>
+__cpp_lib_ranges                                        202211L <algorithm> <functional> <iterator>
                                                                 <memory> <ranges>
 __cpp_lib_ranges_as_const                               202207L <ranges>
 __cpp_lib_ranges_as_rvalue                              202207L <ranges>
@@ -405,7 +405,7 @@ __cpp_lib_within_lifetime                               202306L <type_traits>
 # if _LIBCPP_AVAILABILITY_HAS_PMR
 #   define __cpp_lib_polymorphic_allocator              201902L
 # endif
-# define __cpp_lib_ranges                               202207L
+# define __cpp_lib_ranges                               202211L
 # define __cpp_lib_remove_cvref                         201711L
 # if !defined(_LIBCPP_HAS_NO_THREADS) && _LIBCPP_AVAILABILITY_HAS_SYNC
 #   define __cpp_lib_semaphore                          201907L
diff --git a/libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.pass.cpp b/libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.pass.cpp
index 566638263e887..8cd515d8e7fb4 100644
--- a/libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.pass.cpp
+++ b/libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.pass.cpp
@@ -11,6 +11,14 @@
 // template<class I>
 // unspecified iter_move;
 
+// Note: this struct is intentionally defined before any other header is included.
+// Custom `iter_move` must be visible to `std::ranges::iter_move` CPO from `<iterator>` header.
+namespace nest {
+struct StructWithGlobalIterMove {};
+} // namespace nest
+
+int&& iter_move(nest::StructWithGlobalIterMove);
+
 #include <algorithm>
 #include <array>
 #include <cassert>
@@ -186,6 +194,9 @@ template<class T> struct Holder { T t; };
 static_assert(std::is_invocable_v<IterMoveT, Holder<Incomplete>**>);
 static_assert(std::is_invocable_v<IterMoveT, Holder<Incomplete>**&>);
 
+// Ordinary unqualified lookup should not be performed.
+static_assert(!std::is_invocable_v<IterMoveT, nest::StructWithGlobalIterMove&>);
+
 int main(int, char**)
 {
   test();
diff --git a/libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.swap/iter_swap.pass.cpp b/libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.swap/iter_swap.pass.cpp
index dd78707f25409..692ddef195d2c 100644
--- a/libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.swap/iter_swap.pass.cpp
+++ b/libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.swap/iter_swap.pass.cpp
@@ -47,6 +47,12 @@ static_assert( std::is_invocable_v<IterSwapT&&, HasIterSwap&, HasIterSwap&>);
 static_assert( std::is_invocable_v<IterSwapT&&, HasIterSwap&, int&>);
 static_assert(!std::is_invocable_v<IterSwapT&&, int&, HasIterSwap&>);
 
+struct NotMoreSpecializedIterSwap {
+  friend void iter_swap(auto&, auto&);
+};
+
+static_assert(!std::is_invocable_v<IterSwapT, NotMoreSpecializedIterSwap&, NotMoreSpecializedIterSwap&>);
+
 struct NodiscardIterSwap {
   [[nodiscard]] friend int iter_swap(NodiscardIterSwap&, NodiscardIterSwap&) { return 0; }
 };
diff --git a/libcxx/test/std/language.support/cmp/cmp.alg/ordinary_unqualified_lookup_helpers.h b/libcxx/test/std/language.support/cmp/cmp.alg/ordinary_unqualified_lookup_helpers.h
new file mode 100644
index 0000000000000..4cbe163c312f4
--- /dev/null
+++ b/libcxx/test/std/language.support/cmp/cmp.alg/ordinary_unqualified_lookup_helpers.h
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef TEST_STD_LANGUAGE_SUPPORT_CMP_CMP_ALG_ORDINARY_UNQUALIFIED_LOOKUP_HELPERS_H
+#define TEST_STD_LANGUAGE_SUPPORT_CMP_CMP_ALG_ORDINARY_UNQUALIFIED_LOOKUP_HELPERS_H
+
+// Note: this header should be included before any other header.
+// Comparison functions defined here must be visible to CPOs from `<compare>` header.
+
+namespace nest {
+struct StructWithGlobalCmpFunctions {};
+} // namespace nest
+
+struct ConvertibleToComparisonType;
+
+ConvertibleToComparisonType strong_order(nest::StructWithGlobalCmpFunctions, nest::StructWithGlobalCmpFunctions);
+ConvertibleToComparisonType weak_order(nest::StructWithGlobalCmpFunctions, nest::StructWithGlobalCmpFunctions);
+ConvertibleToComparisonType partial_order(nest::StructWithGlobalCmpFunctions, nest::StructWithGlobalCmpFunctions);
+
+#include <compare> // Intentionally included here, so we can define `ConvertibleToComparisonType` later.
+
+struct ConvertibleToComparisonType {
+  operator std::strong_ordering() const;
+  operator std::weak_ordering() const;
+  operator std::partial_ordering() const;
+};
+
+#endif // TEST_STD_LANGUAGE_SUPPORT_CMP_CMP_ALG_ORDINARY_UNQUALIFIED_LOOKUP_HELPERS_H
diff --git a/libcxx/test/std/language.support/cmp/cmp.alg/partial_order.pass.cpp b/libcxx/test/std/language.support/cmp/cmp.alg/partial_order.pass.cpp
index bd313889b1a4e..d6376f0a5cb2a 100644
--- a/libcxx/test/std/language.support/cmp/cmp.alg/partial_order.pass.cpp
+++ b/libcxx/test/std/language.support/cmp/cmp.alg/partial_order.pass.cpp
@@ -12,6 +12,10 @@
 
 // template<class T> constexpr partial_ordering partial_order(const T& a, const T& b);
 
+// Note: this header is intentionally included before any other header.
+// Comparison functions defined there must be visible to CPOs from `<compare>` header.
+#include "ordinary_unqualified_lookup_helpers.h"
+
 #include <compare>
 
 #include <cassert>
@@ -240,6 +244,11 @@ constexpr bool test_1_4()
     return true;
 }
 
+// Ordinary unqualified lookup should not be performed.
+static_assert(!std::is_invocable_v<decltype(std::partial_order),
+                                   nest::StructWithGlobalCmpFunctions,
+                                   nest::StructWithGlobalCmpFunctions>);
+
 int main(int, char**)
 {
     test_1_1();
diff --git a/libcxx/test/std/language.support/cmp/cmp.alg/strong_order.pass.cpp b/libcxx/test/std/language.support/cmp/cmp.alg/strong_order.pass.cpp
index ac6b6879f7730..5c26a0be23f0a 100644
--- a/libcxx/test/std/language.support/cmp/cmp.alg/strong_order.pass.cpp
+++ b/libcxx/test/std/language.support/cmp/cmp.alg/strong_order.pass.cpp
@@ -12,6 +12,10 @@
 
 // template<class T> constexpr strong_ordering strong_order(const T& a, const T& b);
 
+// Note: this header is intentionally included before any other header.
+// Comparison functions defined there must be visible to CPOs from `<compare>` header.
+#include "ordinary_unqualified_lookup_helpers.h"
+
 #include <compare>
 
 #include <cassert>
@@ -448,6 +452,11 @@ constexpr bool test_1_4()
     return true;
 }
 
+// Ordinary unqualified lookup should not be performed.
+static_assert(!std::is_invocable_v<decltype(std::strong_order),
+                                   nest::StructWithGlobalCmpFunctions,
+                                   nest::StructWithGlobalCmpFunctions>);
+
 int main(int, char**)
 {
     test_1_1();
diff --git a/libcxx/test/std/language.support/cmp/cmp.alg/weak_order.pass.cpp b/libcxx/test/std/language.support/cmp/cmp.alg/weak_order.pass.cpp
index 09d720196e0b2..0dc79acc99ed9 100644
--- a/libcxx/test/std/language.support/cmp/cmp.alg/weak_order.pass.cpp
+++ b/libcxx/test/std/language.support/cmp/cmp.alg/weak_order.pass.cpp
@@ -12,6 +12,10 @@
 
 // template<class T> constexpr weak_ordering weak_order(const T& a, const T& b);
 
+// Note: this header is intentionally included before any other header.
+// Comparison functions defined there must be visible to CPOs from `<compare>` header.
+#include "ordinary_unqualified_lookup_helpers.h"
+
 #include <compare>
 
 #include <cassert>
@@ -493,6 +497,11 @@ constexpr bool test_1_5()
     return true;
 }
 
+// Ordinary unqualified lookup should not be performed.
+static_assert(!std::is_invocable_v<decltype(std::weak_order),
+                                   nest::StructWithGlobalCmpFunctions,
+                                   nest::StructWithGlobalCmpFunctions>);
+
 int main(int, char**)
 {
     test_1_1();
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/algorithm.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/algorithm.version.compile.pass.cpp
index ec6503ec23755..918c6d35f730d 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/algorithm.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/algorithm.version.compile.pass.cpp
@@ -20,7 +20,7 @@
     __cpp_lib_constexpr_algorithms           201806L [C++20]
     __cpp_lib_freestanding_algorithm         202311L [C++26]
     __cpp_lib_parallel_algorithm             201603L [C++17]
-    __cpp_lib_ranges                         202207L [C++20]
+    __cpp_lib_ranges                         202211L [C++20]
     __cpp_lib_ranges_starts_ends_with        202106L [C++23]
     __cpp_lib_robust_nonmodifying_seq_ops    201304L [C++14]
     __cpp_lib_sample                         201603L [C++17]
@@ -201,8 +201,8 @@
 # ifndef __cpp_lib_ranges
 #   error "__cpp_lib_ranges should be defined in c++20"
 # endif
-# if __cpp_lib_ranges != 202207L
-#   error "__cpp_lib_ranges should have the value 202207L in c++20"
+# if __cpp_lib_ranges != 202211L
+#   error "__cpp_lib_ranges should have the value 202211L in c++20"
 # endif
 
 # ifdef __cpp_lib_ranges_starts_ends_with
@@ -266,8 +266,8 @@
 # ifndef __cpp_lib_ranges
 #   error "__cpp_lib_ranges should be defined in c++23"
 # endif
-# if __cpp_lib_ranges != 202207L
-#   error "__cpp_lib_ranges should have the value 202207L in c++23"
+# if __cpp_lib_ranges != 202211L
+#   error "__cpp_lib_ranges should have the value 202211L in c++23"
 # endif
 
 # if !defined(_LIBCPP_VERSION)
@@ -349,8 +349,8 @@
 # ifndef __cpp_lib_ranges
 #   error "__cpp_lib_ranges should be defined in c++26"
 # endif
-# if __cpp_lib_ranges != 202207L
-#   error "__cpp_lib_ranges should have the value 202207L in c++26"
+# if __cpp_lib_ranges != 202211L
+#   error "__cpp_lib_ranges should have the value 202211L in c++26"
 # endif
 
 # if !defined(_LIBCPP_VERSION)
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/functional.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/functional.version.compile.pass.cpp
index 72c96c62b64c4..55674d104fab9 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/functional.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/functional.version.compile.pass.cpp
@@ -28,7 +28,7 @@
     __cpp_lib_invoke_r                 202106L [C++23]
     __cpp_lib_move_only_function       202110L [C++23]
     __cpp_lib_not_fn                   201603L [C++17]
-    __cpp_lib_ranges                   202207L [C++20]
+    __cpp_lib_ranges                   202211L [C++20]
     __cpp_lib_result_of_sfinae         201210L [C++14]
     __cpp_lib_transparent_operators    201210L [C++14]
                                        201510L [C++17]
@@ -293,8 +293,8 @@
 # ifndef __cpp_lib_ranges
 #   error "__cpp_lib_ranges should be defined in c++20"
 # endif
-# if __cpp_lib_ranges != 202207L
-#   error "__cpp_lib_ranges should have the value 202207L in c++20"
+# if __cpp_lib_ranges != 202211L
+#   error "__cpp_lib_ranges should have the value 202211L in c++20"
 # endif
 
 # ifndef __cpp_lib_result_of_sfinae
@@ -399,8 +399,8 @@
 # ifndef __cpp_lib_ranges
 #   error "__cpp_lib_ranges should be defined in c++23"
 # endif
-# if __cpp_lib_ranges != 202207L
-#   error "__cpp_lib_ranges should have the value 202207L in c++23"
+# if __cpp_lib_ranges != 202211L
+#   error "__cpp_lib_ranges should have the value 202211L in c++23"
 # endif
 
 # ifndef __cpp_lib_result_of_sfinae
@@ -523,8 +523,8 @@
 # ifndef __cpp_lib_ranges
 #   error "__cpp_lib_ranges should be defined in c++26"
 # endif
-# if __cpp_lib_ranges != 202207L
-#   error "__cpp_lib_ranges should have the value 202207L in c++26"
+# if __cpp_lib_ranges != 202211L
+#   error "__cpp_lib_ranges should have the value 202211L in c++26"
 # endif
 
 # ifndef __cpp_lib_result_of_sfinae
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/iterator.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/iterator.version.compile.pass.cpp
index 700907ce9bb07..6c652e694f6dd 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/iterator.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/iterator.version.compile.pass.cpp
@@ -23,7 +23,7 @@
     __cpp_lib_move_iterator_concept         202207L [C++20]
     __cpp_lib_nonmember_container_access    201411L [C++17]
     __cpp_lib_null_iterators                201304L [C++14]
-    __cpp_lib_ranges                        202207L [C++20]
+    __cpp_lib_ranges                        202211L [C++20]
     __cpp_lib_ssize                         201902L [C++20]
 */
 
@@ -197,8 +197,8 @@
 # ifndef __cpp_lib_ranges
 #   error "__cpp_lib_ranges should be defined in c++20"
 # endif
-# if __cpp_lib_ranges != 202207L
-#   error "__cpp_lib_ranges should have the value 202207L in c++20"
+# if __cpp_lib_ranges != 202211L
+#   error "__cpp_lib_ranges should have the value 202211L in c++20"
 # endif
 
 # ifndef __cpp_lib_ssize
@@ -255,8 +255,8 @@
 # ifndef __cpp_lib_ranges
 #   error "__cpp_lib_rang...
[truncated]

github-actions · 2023-12-05T23:02:53Z

✅ With the latest revision this PR passed the Python code formatter.

github-actions · 2023-12-05T23:02:57Z

✅ With the latest revision this PR passed the C/C++ code formatter.

philnik777 · 2023-12-06T15:35:02Z

Could you add some reasoning why this should be DRed?

JMazurkiewicz · 2023-12-06T19:42:02Z

Could you add some reasoning why this should be DRed?

MSVC and libstdc++ already implemented this paper as a DR. It mainly fixes this (rather) unexpected behaviour:

// https://godbolt.org/z/9h954faET
#include <ranges>

struct Ints {
    friend int* begin(const Ints&);
    friend int* end(const Ints&);
};

// Good
static_assert(std::ranges::range<const Ints>);

// FAIL! It looks like defect in C++20 ranges design.
static_assert(std::ranges::range<Ints>);

And quote from the paper (end of §4):

[...] the poison pills prevent reasonable code from working and it’s entirely unclear whether they prevent unreasonable code from working.

cjdb · 2023-12-06T23:27:24Z

I support applying this to C++20.

libcxx/utils/generate_feature_test_macro_components.py

libcxx/docs/FeatureTestMacroTable.rst

...test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.pass.cpp

...rator.requirements/iterator.cust/robust_against_ordinary_unqualified_lookup.compile.pass.cpp

…ests into file Add extra checks too.

huixie90

LGTM.

* Some docs should've been updated in llvm#74534, this PR does this. * llvm#89148 should've bumped `__cpp_lib_ranges` macro to 202211 (value mentioned by "P2602R2 Poison Pills are Too Toxic") * Drive-by: fix order of notes in `Cxx23.rst`

[libc++] P2602R2 Poison Pills are Too Toxic

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JMazurkiewicz requested a review from a team as a code owner December 5, 2023 23:00

llvmbot added the libc++ libc++ C++ Standard Library. Not GNU libstdc++. Not libc++abi. label Dec 5, 2023

Make 🐍 formatter happy

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llvm-project Mega-Update microsoft/STL#4263

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JMazurkiewicz added 13 commits January 10, 2024 23:35

Merge branch 'main' into libcxx/ranges/poison-pills

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ccfae95

Merge branch 'main' into libcxx/ranges/poison-pills

5f0ad59

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Merge branch 'main' into libcxx/ranges/poison-pills

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Fix value of __cpp_lib_ranges FTM

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Merge branch 'main' into libcxx/ranges/poison-pills

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Merge branch 'main' into libcxx/ranges/poison-pills

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huixie90 reviewed Feb 26, 2024

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JMazurkiewicz added 3 commits February 26, 2024 16:37

Separate ordinary unqualified lookup tests.

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Revert changes to __cpp_lib_ranges

a1dbe7d

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Merge branch 'main' into libcxx/ranges/poison-pills

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JMazurkiewicz requested a review from huixie90 February 26, 2024 19:59

Merge branch 'main' into libcxx/ranges/poison-pills

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huixie90 reviewed Mar 7, 2024

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JMazurkiewicz added 2 commits March 7, 2024 18:05

Merge robust_against_ordinary_unqualified_lookup.compile.pass.cpp t…

191568d

…ests into file Add extra checks too.

Merge branch 'main' into libcxx/ranges/poison-pills

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var-const added the ranges Issues related to `<ranges>` label Mar 8, 2024

Merge branch 'main' into libcxx/ranges/poison-pills

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huixie90 approved these changes Mar 13, 2024

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huixie90 merged commit 12978b3 into llvm:main Mar 16, 2024
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JMazurkiewicz deleted the libcxx/ranges/poison-pills branch March 18, 2024 08:29

JMazurkiewicz mentioned this pull request Apr 11, 2024

[libc++] Follow-up to "Poison Pills are Too Toxic" #88383

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StephanTLavavej mentioned this pull request May 31, 2024

llvm-project Meso-Update microsoft/STL#4702

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[libc++] P2602R2 Poison Pills are Too Toxic #74534

[libc++] P2602R2 Poison Pills are Too Toxic #74534

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[libc++] P2602R2 Poison Pills are Too Toxic #74534

[libc++] P2602R2 Poison Pills are Too Toxic #74534

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JMazurkiewicz commented Dec 5, 2023 • edited

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