[libcxx-commits] [libcxx] [libc++] Make `__wrap_iter` comparison operators hidden friends (PR #179590)
William Tran-Viet via libcxx-commits
libcxx-commits at lists.llvm.org
Tue Feb 3 17:54:38 PST 2026
https://github.com/smallp-o-p updated https://github.com/llvm/llvm-project/pull/179590
>From 1d4955a0bd3d2efe76c1735e03bf10e3ab46fcf4 Mon Sep 17 00:00:00 2001
From: William Tran-Viet <wtranviet at proton.me>
Date: Tue, 3 Feb 2026 20:46:58 -0500
Subject: [PATCH 1/2] Make comparison operators hidden friends
---
libcxx/include/__iterator/wrap_iter.h | 192 +++++++++++++-------------
1 file changed, 93 insertions(+), 99 deletions(-)
diff --git a/libcxx/include/__iterator/wrap_iter.h b/libcxx/include/__iterator/wrap_iter.h
index 128aeab3ac7cd..ab5b0d2b6f706 100644
--- a/libcxx/include/__iterator/wrap_iter.h
+++ b/libcxx/include/__iterator/wrap_iter.h
@@ -119,117 +119,111 @@ class __wrap_iter {
friend struct array;
template <class _Tp, class>
friend struct __optional_iterator;
-};
-template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
- return __x.base() == __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
- return __x.base() == __y.base();
-}
-
-template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
-operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
- return __x.base() < __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
-operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
- return __x.base() < __y.base();
-}
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator==(const __wrap_iter& __x, const __wrap_iter& __y) _NOEXCEPT {
+ return __x.base() == __y.base();
+ }
+
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator==(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
+ return __x.base() == __y.base();
+ }
+
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
+ operator<(const __wrap_iter& __x, const __wrap_iter& __y) _NOEXCEPT {
+ return __x.base() < __y.base();
+ }
+
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
+ operator<(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
+ return __x.base() < __y.base();
+ }
#if _LIBCPP_STD_VER <= 17
-template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI
-_LIBCPP_CONSTEXPR bool operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
- return !(__x == __y);
-}
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
- return !(__x == __y);
-}
-template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
- return __y < __x;
-}
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
- return __y < __x;
-}
-
-template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
- return !(__x < __y);
-}
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
- return !(__x < __y);
-}
-
-template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
- return !(__y < __x);
-}
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
-operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
- return !(__y < __x);
-}
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator!=(const __wrap_iter& __x, const __wrap_iter& __y) _NOEXCEPT {
+ return !(__x == __y);
+ }
-#else
-template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI constexpr strong_ordering
-operator<=>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) noexcept {
- if constexpr (three_way_comparable_with<_Iter1, _Iter2, strong_ordering>) {
- return __x.base() <=> __y.base();
- } else {
- if (__x.base() < __y.base())
- return strong_ordering::less;
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator!=(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
+ return !(__x == __y);
+ }
- if (__x.base() == __y.base())
- return strong_ordering::equal;
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator>(const __wrap_iter& __x, const __wrap_iter& __y) _NOEXCEPT {
+ return __y < __x;
+ }
+
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator>(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
+ return __y < __x;
+ }
- return strong_ordering::greater;
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator>=(const __wrap_iter& __x, const __wrap_iter& __y) _NOEXCEPT {
+ return !(__x < __y);
+ }
+
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator>=(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
+ return !(__x < __y);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator<=(const __wrap_iter& __x, const __wrap_iter& __y) _NOEXCEPT {
+ return !(__y < __x);
+ }
+
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
+ operator<=(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
+ return !(__y < __x);
+ }
+
+#else
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend constexpr strong_ordering
+ operator<=>(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) noexcept {
+ if constexpr (three_way_comparable_with<_Iter, _Iter2, strong_ordering>) {
+ return __x.base() <=> __y.base();
+ } else {
+ if (__x.base() < __y.base())
+ return strong_ordering::less;
+
+ if (__x.base() == __y.base())
+ return strong_ordering::equal;
+
+ return strong_ordering::greater;
+ }
}
-}
#endif // _LIBCPP_STD_VER >= 20
-template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
#ifndef _LIBCPP_CXX03_LANG
-auto operator-(const __wrap_iter<_Iter1>& __x,
- const __wrap_iter<_Iter2>& __y) _NOEXCEPT->decltype(__x.base() - __y.base())
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR_SINCE_CXX14 auto
+ operator-(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT->decltype(__x.base() - __y.base())
#else
-typename __wrap_iter<_Iter1>::difference_type
-operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+ template <class _Iter2>
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR_SINCE_CXX14 typename __wrap_iter::difference_type
+ operator-(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
#endif // C++03
-{
- return __x.base() - __y.base();
-}
-
-template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter<_Iter1>
-operator+(typename __wrap_iter<_Iter1>::difference_type __n, __wrap_iter<_Iter1> __x) _NOEXCEPT {
- __x += __n;
- return __x;
-}
+ {
+ return __x.base() - __y.base();
+ }
+
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter
+ operator+(typename __wrap_iter::difference_type __n, __wrap_iter __x) _NOEXCEPT {
+ __x += __n;
+ return __x;
+ }
+};
#if _LIBCPP_STD_VER <= 17
template <class _It>
>From 0d64ab591e37e213a5767f4a72c412bf3d7120bb Mon Sep 17 00:00:00 2001
From: William Tran-Viet <wtranviet at proton.me>
Date: Tue, 3 Feb 2026 20:54:29 -0500
Subject: [PATCH 2/2] Formatting
---
libcxx/include/__iterator/wrap_iter.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/libcxx/include/__iterator/wrap_iter.h b/libcxx/include/__iterator/wrap_iter.h
index ab5b0d2b6f706..234c9a4f8c704 100644
--- a/libcxx/include/__iterator/wrap_iter.h
+++ b/libcxx/include/__iterator/wrap_iter.h
@@ -143,8 +143,8 @@ class __wrap_iter {
}
#if _LIBCPP_STD_VER <= 17
- _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR bool
- operator!=(const __wrap_iter& __x, const __wrap_iter& __y) _NOEXCEPT {
+ _LIBCPP_HIDE_FROM_ABI friend
+ _LIBCPP_CONSTEXPR bool operator!=(const __wrap_iter& __x, const __wrap_iter& __y) _NOEXCEPT {
return !(__x == __y);
}
@@ -211,8 +211,8 @@ class __wrap_iter {
operator-(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT->decltype(__x.base() - __y.base())
#else
template <class _Iter2>
- _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR_SINCE_CXX14 typename __wrap_iter::difference_type
- operator-(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+ _LIBCPP_HIDE_FROM_ABI friend _LIBCPP_CONSTEXPR_SINCE_CXX14
+ typename __wrap_iter::difference_type operator-(const __wrap_iter& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
#endif // C++03
{
return __x.base() - __y.base();
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