[libcxx-commits] [libcxx] [libc++] Fix use of static in constexpr (PR #160180)

[Prabhu Rajasekaran via libcxx-commits]

https://github.com/Prabhuk updated https://github.com/llvm/llvm-project/pull/160180

>From d2a2061698977999952edcca8638cb0a7e9d8dee Mon Sep 17 00:00:00 2001
From: prabhukr <prabhukr at google.com>
Date: Mon, 22 Sep 2025 19:24:11 +0000
Subject: [PATCH 1/2] [libc++] Fix use of static in constexpr

`static` is not allowed inside constexpr functions in C++ versions below
23. This is causing a build error when compiled with GCC and warning
when compiled with Clang. This patch fixes this.
---
 libcxx/include/__algorithm/make_heap.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libcxx/include/__algorithm/make_heap.h b/libcxx/include/__algorithm/make_heap.h
index 8cfeda2b59811..c592656374dac 100644
--- a/libcxx/include/__algorithm/make_heap.h
+++ b/libcxx/include/__algorithm/make_heap.h
@@ -36,7 +36,8 @@ __make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compar
   using __diff_t     = __iter_diff_t<_RandomAccessIterator>;
   const __diff_t __n = __last - __first;
 
-  static const bool __assume_both_children = is_arithmetic<__iter_value_type<_RandomAccessIterator> >::value;
+  _LIBCPP_CONSTEXPR_SINCE_CXX14 const bool __assume_both_children =
+      is_arithmetic<__iter_value_type<_RandomAccessIterator> >::value;
 
   // While it would be correct to always assume we have both children, in practice we observed this to be a performance
   // improvement only for arithmetic types.

>From a075374c0440770d130d05ab31266bff6fd4fb34 Mon Sep 17 00:00:00 2001
From: Prabhu Rajasekaran <prabhukrllvm at gmail.com>
Date: Mon, 22 Sep 2025 16:34:06 -0700
Subject: [PATCH 2/2] Update libcxx/include/__algorithm/make_heap.h

Drop static and constexpr for __assume_both_children. Simply leave it to be plain `const`.

Co-authored-by: A. Jiang <de34 at live.cn>
---
 libcxx/include/__algorithm/make_heap.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/libcxx/include/__algorithm/make_heap.h b/libcxx/include/__algorithm/make_heap.h
index c592656374dac..8aff8ce588568 100644
--- a/libcxx/include/__algorithm/make_heap.h
+++ b/libcxx/include/__algorithm/make_heap.h
@@ -36,8 +36,7 @@ __make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compar
   using __diff_t     = __iter_diff_t<_RandomAccessIterator>;
   const __diff_t __n = __last - __first;
 
-  _LIBCPP_CONSTEXPR_SINCE_CXX14 const bool __assume_both_children =
-      is_arithmetic<__iter_value_type<_RandomAccessIterator> >::value;
+  const bool __assume_both_children = is_arithmetic<__iter_value_type<_RandomAccessIterator> >::value;
 
   // While it would be correct to always assume we have both children, in practice we observed this to be a performance
   // improvement only for arithmetic types.