[libcxx-commits] [libcxx] [libc++][ranges] LWG3610: `iota_view::size` sometimes rejects integer-class types (PR #155169)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Hristo Hristov (H-G-Hristov)

<details>
<summary>Changes</summary>

Fixes #<!-- -->104948

- https://wg21.link/LWG3610

---
Full diff: https://github.com/llvm/llvm-project/pull/155169.diff


3 Files Affected:

- (modified) libcxx/docs/Status/Cxx23Issues.csv (+1-1) 
- (modified) libcxx/include/__ranges/iota_view.h (+1-1) 
- (modified) libcxx/test/std/ranges/range.factories/range.iota.view/size.pass.cpp (+18) 


``````````diff
diff --git a/libcxx/docs/Status/Cxx23Issues.csv b/libcxx/docs/Status/Cxx23Issues.csv
index 189f8452e0678..38571dabae463 100644
--- a/libcxx/docs/Status/Cxx23Issues.csv
+++ b/libcxx/docs/Status/Cxx23Issues.csv
@@ -143,7 +143,7 @@
 "`LWG3598 <https://wg21.link/LWG3598>`__","``system_category().default_error_condition(0)`` is underspecified","2022-02 (Virtual)","","",""
 "`LWG3601 <https://wg21.link/LWG3601>`__","common_iterator's postfix-proxy needs ``indirectly_readable`` ","2022-02 (Virtual)","","",""
 "`LWG3607 <https://wg21.link/LWG3607>`__","``contiguous_iterator`` should not be allowed to have custom ``iter_move`` and ``iter_swap`` behavior","2022-02 (Virtual)","|Nothing To Do|","",""
-"`LWG3610 <https://wg21.link/LWG3610>`__","``iota_view::size`` sometimes rejects integer-class types","2022-02 (Virtual)","","",""
+"`LWG3610 <https://wg21.link/LWG3610>`__","``iota_view::size`` sometimes rejects integer-class types","2022-02 (Virtual)","|Complete|","22",""
 "`LWG3612 <https://wg21.link/LWG3612>`__","Inconsistent pointer alignment in ``std::format`` ","2022-02 (Virtual)","|Complete|","14",""
 "`LWG3616 <https://wg21.link/LWG3616>`__","LWG 3498 seems to miss the non-member ``swap`` for ``basic_syncbuf`` ","2022-02 (Virtual)","|Complete|","18",""
 "`LWG3618 <https://wg21.link/LWG3618>`__","Unnecessary ``iter_move`` for ``transform_view::iterator`` ","2022-02 (Virtual)","|Complete|","19",""
diff --git a/libcxx/include/__ranges/iota_view.h b/libcxx/include/__ranges/iota_view.h
index 4b84585258b91..cf401a4665fcd 100644
--- a/libcxx/include/__ranges/iota_view.h
+++ b/libcxx/include/__ranges/iota_view.h
@@ -348,7 +348,7 @@ class iota_view : public view_interface<iota_view<_Start, _BoundSentinel>> {
 
   _LIBCPP_HIDE_FROM_ABI constexpr auto size() const
     requires(same_as<_Start, _BoundSentinel> && __advanceable<_Start>) ||
-            (integral<_Start> && integral<_BoundSentinel>) || sized_sentinel_for<_BoundSentinel, _Start>
+            (__integer_like<_Start> && __integer_like<_BoundSentinel>) || sized_sentinel_for<_BoundSentinel, _Start>
   {
     if constexpr (__integer_like<_Start> && __integer_like<_BoundSentinel>) {
       return (__value_ < 0)
diff --git a/libcxx/test/std/ranges/range.factories/range.iota.view/size.pass.cpp b/libcxx/test/std/ranges/range.factories/range.iota.view/size.pass.cpp
index b894bc542be10..90afec2fba177 100644
--- a/libcxx/test/std/ranges/range.factories/range.iota.view/size.pass.cpp
+++ b/libcxx/test/std/ranges/range.factories/range.iota.view/size.pass.cpp
@@ -16,8 +16,21 @@
 #include <ranges>
 
 #include "test_macros.h"
+#define TEST_HAS_NO_INT128
+#include "type_algorithms.h"
 #include "types.h"
 
+template <typename T>
+concept HasSize = requires(const T t) { t.size(); };
+
+struct CheckForSize {
+  template <class T>
+  constexpr void operator()() {
+    static_assert(HasSize<std::ranges::iota_view<T, int>>);
+    static_assert(HasSize<std::ranges::iota_view<T, T>>);
+  }
+};
+
 constexpr bool test() {
   // Both are integer like and both are less than zero.
   {
@@ -99,6 +112,11 @@ constexpr bool test() {
     assert(sz == 10);
   }
 
+  // LWG3610: `iota_view::size` sometimes rejects integer-class types
+  {
+    types::for_each(types::integer_types{}, CheckForSize{});
+  }
+
   return true;
 }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/155169