[libcxx-commits] [libcxx] [libc++][ranges] LWG3610: `iota_view::size` sometimes rejects integer-class types (PR #155169)
Hristo Hristov via libcxx-commits
libcxx-commits at lists.llvm.org
Thu Aug 28 02:24:14 PDT 2025
https://github.com/H-G-Hristov updated https://github.com/llvm/llvm-project/pull/155169
>From 44284cde6d74a8c0a849f9f30feb23a37a796820 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm at gmail.com>
Date: Sun, 24 Aug 2025 13:44:49 +0300
Subject: [PATCH 1/3] [libc++][ranges] LWG3610: iota_view::size sometimes
rejects integer-class types
Fixes #104948
- https://wg21.link/LWG3610
---
libcxx/docs/Status/Cxx23Issues.csv | 2 +-
libcxx/include/__ranges/iota_view.h | 2 +-
.../range.iota.view/size.pass.cpp | 18 ++++++++++++++++++
3 files changed, 20 insertions(+), 2 deletions(-)
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;
}
>From bee2ac2a7a4da6b6f234106cbb3070577bf49a96 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm at gmail.com>
Date: Mon, 25 Aug 2025 11:28:26 +0300
Subject: [PATCH 2/3] Updated test
---
.../ranges/range.factories/range.iota.view/size.pass.cpp | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
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 90afec2fba177..315e581aed577 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
@@ -24,10 +24,11 @@ template <typename T>
concept HasSize = requires(const T t) { t.size(); };
struct CheckForSize {
- template <class T>
+ template <class IntegerLikeT>
constexpr void operator()() {
- static_assert(HasSize<std::ranges::iota_view<T, int>>);
- static_assert(HasSize<std::ranges::iota_view<T, T>>);
+ types::for_each(types::integer_types{}, []<typename BoundT>() {
+ static_assert(HasSize<std::ranges::iota_view<IntegerLikeT, BoundT>>);
+ });
}
};
>From 1575d9566e5e65411561e60b928092055ed1ee80 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm at gmail.com>
Date: Mon, 25 Aug 2025 14:26:11 +0300
Subject: [PATCH 3/3] Added `__int128_t` support
---
libcxx/include/__ranges/iota_view.h | 6 ++++++
.../ranges/range.factories/range.iota.view/begin.pass.cpp | 4 ++++
.../ranges/range.factories/range.iota.view/end.pass.cpp | 8 ++++++++
.../iterator/member_typedefs.compile.pass.cpp | 8 ++++++++
.../range.iota.view/iterator/star.pass.cpp | 6 ++++++
.../range.iota.view/iterator/subscript.pass.cpp | 6 ++++++
.../ranges/range.factories/range.iota.view/size.pass.cpp | 1 -
7 files changed, 38 insertions(+), 1 deletion(-)
diff --git a/libcxx/include/__ranges/iota_view.h b/libcxx/include/__ranges/iota_view.h
index cf401a4665fcd..275694a054057 100644
--- a/libcxx/include/__ranges/iota_view.h
+++ b/libcxx/include/__ranges/iota_view.h
@@ -57,11 +57,17 @@ struct __get_wider_signed {
return type_identity<int>{};
else if constexpr (sizeof(_Int) < sizeof(long))
return type_identity<long>{};
+ else if constexpr (sizeof(_Int) < sizeof(long long))
+ return type_identity<long long>{};
else
+# if _LIBCPP_HAS_INT128
+ return type_identity<__int128_t>{};
+# else
return type_identity<long long>{};
static_assert(
sizeof(_Int) <= sizeof(long long), "Found integer-like type that is bigger than largest integer like type.");
+# endif
}
using type = typename decltype(__call())::type;
diff --git a/libcxx/test/std/ranges/range.factories/range.iota.view/begin.pass.cpp b/libcxx/test/std/ranges/range.factories/range.iota.view/begin.pass.cpp
index 06419c1b14ee0..dbe052ea18287 100644
--- a/libcxx/test/std/ranges/range.factories/range.iota.view/begin.pass.cpp
+++ b/libcxx/test/std/ranges/range.factories/range.iota.view/begin.pass.cpp
@@ -40,6 +40,10 @@ constexpr void testType() {
constexpr bool test() {
testType<SomeInt>();
+#ifndef TEST_HAS_NO_INT128
+ testType<__int128_t>();
+ testType<__uint128_t>();
+#endif
testType<long long>();
testType<unsigned long long>();
testType<signed long>();
diff --git a/libcxx/test/std/ranges/range.factories/range.iota.view/end.pass.cpp b/libcxx/test/std/ranges/range.factories/range.iota.view/end.pass.cpp
index 6abbef55b6ba7..d12079fdb5eec 100644
--- a/libcxx/test/std/ranges/range.factories/range.iota.view/end.pass.cpp
+++ b/libcxx/test/std/ranges/range.factories/range.iota.view/end.pass.cpp
@@ -61,6 +61,14 @@ constexpr void testType(U u) {
constexpr bool test() {
testType<SomeInt>(SomeInt(10));
testType<SomeInt>(IntComparableWith(SomeInt(10)));
+#ifndef TEST_HAS_NO_INT128
+ testType<__int128_t>(__int128_t(10));
+ testType<__uint128_t>(__uint128_t(10));
+#endif
+ testType<signed long long>(10LL);
+ testType<unsigned long long>(10ULL);
+ testType<signed long long>(IntComparableWith<signed long long>(10));
+ testType<unsigned long long>(IntComparableWith<unsigned long long>(10));
testType<signed long>(IntComparableWith<signed long>(10));
testType<unsigned long>(IntComparableWith<unsigned long>(10));
testType<int>(IntComparableWith<int>(10));
diff --git a/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/member_typedefs.compile.pass.cpp b/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/member_typedefs.compile.pass.cpp
index c2f7fd14042a8..2cd7105adad4b 100644
--- a/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/member_typedefs.compile.pass.cpp
+++ b/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/member_typedefs.compile.pass.cpp
@@ -106,7 +106,11 @@ void test() {
// Same as below, if there is no type larger than long, we can just use that.
static_assert(sizeof(Iter::difference_type) >= sizeof(long));
static_assert(std::is_signed_v<Iter::difference_type>);
+#ifdef TEST_HAS_NO_INT128
LIBCPP_STATIC_ASSERT(std::same_as<Iter::difference_type, long long>);
+#else
+ LIBCPP_STATIC_ASSERT(std::same_as<Iter::difference_type, __int128_t>);
+#endif
}
{
const std::ranges::iota_view<long long> io(0);
@@ -118,7 +122,11 @@ void test() {
// https://eel.is/c++draft/range.iota.view#1.3
static_assert(sizeof(Iter::difference_type) >= sizeof(long long));
static_assert(std::is_signed_v<Iter::difference_type>);
+#ifdef TEST_HAS_NO_INT128
LIBCPP_STATIC_ASSERT(std::same_as<Iter::difference_type, long long>);
+#else
+ LIBCPP_STATIC_ASSERT(std::same_as<Iter::difference_type, __int128_t>);
+#endif
}
{
const std::ranges::iota_view<Decrementable> io;
diff --git a/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/star.pass.cpp b/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/star.pass.cpp
index 570c74e29c686..b776d90c5e5e3 100644
--- a/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/star.pass.cpp
+++ b/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/star.pass.cpp
@@ -81,6 +81,12 @@ constexpr void testType() {
constexpr bool test() {
testType<SomeInt>();
testType<NotNoexceptCopy>();
+#ifndef TEST_HAS_NO_INT128
+ testType<__int128_t>();
+ testType<__uint128_t>();
+#endif
+ testType<signed long long>();
+ testType<unsigned long long>();
testType<signed long>();
testType<unsigned long>();
testType<int>();
diff --git a/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/subscript.pass.cpp b/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/subscript.pass.cpp
index 0e5aca0dd554c..786b63dfeedee 100644
--- a/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/subscript.pass.cpp
+++ b/libcxx/test/std/ranges/range.factories/range.iota.view/iterator/subscript.pass.cpp
@@ -47,6 +47,12 @@ constexpr void testType() {
constexpr bool test() {
testType<SomeInt>();
+#ifndef TEST_HAS_NO_INT128
+ testType<__int128_t>();
+ testType<__uint128_t>();
+#endif
+ testType<signed long long>();
+ testType<unsigned long long>();
testType<signed long>();
testType<unsigned long>();
testType<int>();
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 315e581aed577..bb8215339b2bd 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
@@ -16,7 +16,6 @@
#include <ranges>
#include "test_macros.h"
-#define TEST_HAS_NO_INT128
#include "type_algorithms.h"
#include "types.h"
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