Implement P2441R2 views::join_with

stl/inc/algorithm

@@ -833,11 +833,6 @@ _NODISCARD _CONSTEXPR20 bool is_permutation(_FwdIt1 _First1, _FwdIt1 _Last1, _Fw
 
 #ifdef __cpp_lib_concepts
 namespace ranges {
-    template <class _It, class _Se>
-    concept _Bidi_common = is_same_v<_It, _Se> && bidirectional_iterator<_It>;
-    template <class _Rng>
-    concept _Bidi_common_range = common_range<_Rng> && bidirectional_iterator<iterator_t<_Rng>>;
-
     class _Is_permutation_fn : private _Not_quite_object {
     public:
         using _Not_quite_object::_Not_quite_object;

stl/inc/exception

@@ -389,6 +389,27 @@ template <class _Ty>
 void rethrow_if_nested(const _Ty&) = delete; // requires /GR option
 #endif // _CPPRTTI
 
+class bad_variant_access
+    : public exception { // exception for visit of a valueless variant or get<I> on a variant with index() != I
+public:
+    bad_variant_access() noexcept = default;
+
+    _NODISCARD const char* __CLR_OR_THIS_CALL what() const noexcept override {
+        return "bad variant access";
+    }
+
+#if !_HAS_EXCEPTIONS
+protected:
+    void _Doraise() const override { // perform class-specific exception handling
+        _RAISE(*this);
+    }
+#endif // !_HAS_EXCEPTIONS
+};
+
+[[noreturn]] inline void _Throw_bad_variant_access() {
+    _THROW(bad_variant_access{});
+}
+
 _STD_END
 
 #pragma pop_macro("new")

stl/inc/variant

@@ -392,27 +392,6 @@ struct variant_alternative<_Idx, variant<_Types...>> {
 
 inline constexpr size_t variant_npos = _Meta_npos;
 
-class bad_variant_access
-    : public exception { // exception for visit of a valueless variant or get<I> on a variant with index() != I
-public:
-    bad_variant_access() noexcept = default;
-
-    _NODISCARD const char* __CLR_OR_THIS_CALL what() const noexcept override {
-        return "bad variant access";
-    }
-
-#if !_HAS_EXCEPTIONS
-protected:
-    void _Doraise() const override { // perform class-specific exception handling
-        _RAISE(*this);
-    }
-#endif // !_HAS_EXCEPTIONS
-};
-
-[[noreturn]] inline void _Throw_bad_variant_access() {
-    _THROW(bad_variant_access{});
-}
-
 template <bool _TrivialDestruction, class... _Types>
 class _Variant_storage_ {}; // empty storage (empty "_Types" case)
 

stl/inc/xutility

@@ -2683,6 +2683,11 @@ namespace ranges {
     template <class _Rng>
     concept common_range = range<_Rng> && same_as<iterator_t<_Rng>, sentinel_t<_Rng>>;
 
+    template <class _It, class _Se>
+    concept _Bidi_common = is_same_v<_It, _Se> && bidirectional_iterator<_It>;
+    template <class _Rng>
+    concept _Bidi_common_range = common_range<_Rng> && bidirectional_iterator<iterator_t<_Rng>>;
+
     template <class _Ty>
     concept _Can_empty = requires(_Ty __t) {
         _RANGES empty(__t);

stl/inc/yvals_core.h

@@ -310,6 +310,7 @@
 // P2321R2 zip
 //     (changes to pair, tuple, and vector<bool>::reference only)
 // P2440R1 ranges::iota, ranges::shift_left, ranges::shift_right
+// P2441R2 views::join_with
 // P2442R1 Windowing Range Adaptors: views::chunk, views::slide
 // P2443R1 views::chunk_by
 // P2549R0 unexpected<E>::error()
@@ -1470,6 +1471,7 @@
 #define __cpp_lib_ranges_chunk            202202L
 #define __cpp_lib_ranges_chunk_by         202202L
 #define __cpp_lib_ranges_iota             202202L
+#define __cpp_lib_ranges_join_with        202202L
 #define __cpp_lib_ranges_slide            202202L
 #define __cpp_lib_ranges_starts_ends_with 202106L
 #endif // __cpp_lib_concepts

tests/std/test.lst

@@ -490,6 +490,7 @@ tests\P2415R2_owning_view
 tests\P2440R1_ranges_alg_shift_left
 tests\P2440R1_ranges_alg_shift_right
 tests\P2440R1_ranges_numeric_iota
+tests\P2441R2_views_join_with
 tests\P2442R1_views_chunk
 tests\P2442R1_views_chunk_death
 tests\P2442R1_views_slide

tests/std/tests/P0896R4_common_iterator_death/test.cpp

@@ -54,7 +54,7 @@ void test_case_operator_dereference_sentinel() {
 }
 
 void test_case_operator_dereference_valueless() {
-    CIT cit{_Common_iterator_construct_tag{}};
+    CIT cit{_Variantish_empty_tag{}};
     (void) (*cit); // common_iterator can only be dereferenced if it holds an iterator
 }
 
@@ -64,7 +64,7 @@ void test_case_operator_dereference_const_sentinel() {
 }
 
 void test_case_operator_dereference_const_valueless() {
-    const CIT cit{_Common_iterator_construct_tag{}};
+    const CIT cit{_Variantish_empty_tag{}};
     (void) (*cit); // common_iterator can only be dereferenced if it holds an iterator
 }
 
@@ -73,7 +73,7 @@ void test_case_operator_arrow_sentinel() {
     (void) (cit.operator->()); // common_iterator can only be dereferenced if it holds an iterator
 }
 void test_case_operator_arrow_valueless() {
-    CIT cit{_Common_iterator_construct_tag{}};
+    CIT cit{_Variantish_empty_tag{}};
     (void) (cit.operator->()); // common_iterator can only be dereferenced if it holds an iterator
 }
 
@@ -83,7 +83,7 @@ void test_case_operator_preincrement_sentinel() {
 }
 
 void test_case_operator_preincrement_valueless() {
-    CIT cit{_Common_iterator_construct_tag{}};
+    CIT cit{_Variantish_empty_tag{}};
     ++cit; // common_iterator can only be preincremented if it holds an iterator
 }
 
@@ -93,31 +93,31 @@ void test_case_operator_postincrement_sentinel() {
 }
 
 void test_case_operator_postincrement_valueless() {
-    CIT cit{_Common_iterator_construct_tag{}};
+    CIT cit{_Variantish_empty_tag{}};
     cit++; // common_iterator can only be postincremented if it holds an iterator
 }
 
 void test_case_equality_left_valueless() {
-    CIT cit1{_Common_iterator_construct_tag{}};
+    CIT cit1{_Variantish_empty_tag{}};
     CIT cit2{};
     (void) (cit1 == cit2); // common_iterator can only be compared if it holds a value
 }
 
 void test_case_equality_right_valueless() {
     CIT cit1{};
-    CIT cit2{_Common_iterator_construct_tag{}};
+    CIT cit2{_Variantish_empty_tag{}};
     (void) (cit1 == cit2); // common_iterator can only be compared if it holds a value
 }
 
 void test_case_difference_left_valueless() {
-    CIT cit1{_Common_iterator_construct_tag{}};
+    CIT cit1{_Variantish_empty_tag{}};
     CIT cit2{};
     (void) (cit1 - cit2); // common_iterator can only be subtracted if it holds a value
 }
 
 void test_case_difference_right_valueless() {
     CIT cit1{};
-    CIT cit2{_Common_iterator_construct_tag{}};
+    CIT cit2{_Variantish_empty_tag{}};
     (void) (cit1 - cit2); // common_iterator can only be subtracted if it holds a value
 }
 
@@ -127,7 +127,7 @@ void test_case_iter_move_sentinel() {
 }
 
 void test_case_iter_move_valueless() {
-    CIT cit{_Common_iterator_construct_tag{}};
+    CIT cit{_Variantish_empty_tag{}};
     (void) ranges::iter_move(cit); // can only iter_move from common_iterator if it holds an iterator
 }
 
@@ -138,7 +138,7 @@ void test_case_iter_swap_sentinel_left_sentinel() {
 }
 
 void test_case_iter_swap_sentinel_left_valueless() {
-    CIT cit1{_Common_iterator_construct_tag{}};
+    CIT cit1{_Variantish_empty_tag{}};
     CIT cit2{};
     (void) ranges::iter_swap(cit1, cit2); // can only iter_swap common_iterators if both hold iterators
 }
@@ -151,7 +151,7 @@ void test_case_iter_swap_sentinel_right_sentinel() {
 
 void test_case_iter_swap_sentinel_right_valueless() {
     CIT cit1{};
-    CIT cit2{_Common_iterator_construct_tag{}};
+    CIT cit2{_Variantish_empty_tag{}};
     (void) ranges::iter_swap(cit1, cit2); // can only iter_swap common_iterators if both hold iterators
 }
 

tests/std/tests/P2441R2_views_join_with/env.lst

@@ -0,0 +1,4 @@
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+RUNALL_INCLUDE ..\strict_concepts_latest_matrix.lst