From: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Date: Wed, 5 Mar 2025 13:34:41 +0000 (+0100)
Subject: libstdc++: use if consteval in stable_sort
X-Git-Tag: basepoints/gcc-16~1715
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=24ea4539300d4926d9f073822e68f0d2f369452d;p=thirdparty%2Fgcc.git

libstdc++: use if consteval in stable_sort

This is a C++ >= 26 codepath for supporting constexpr stable_sort, so we
know that we have if consteval available; it just needs protection with
the feature-testing macro. Also merge the return in the same statement.
Amends r15-7708-gff43f9853d3b10.

libstdc++-v3/ChangeLog:

	* include/bits/stl_algo.h (__stable_sort): Use if consteval
	instead of is_constant_evaluated.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
---

diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h
index 41b4d0853b7..c3fea76014c 100644
--- a/libstdc++-v3/include/bits/stl_algo.h
+++ b/libstdc++-v3/include/bits/stl_algo.h
@@ -4987,11 +4987,11 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
 	return;
 
 #if _GLIBCXX_HOSTED
-      if (__is_constant_evaluated())
-	{
-	  std::__inplace_stable_sort(__first, __last, __comp);
-	  return;
-	}
+# if __glibcxx_constexpr_algorithms >= 202306L // >= C++26
+      if consteval {
+	return std::__inplace_stable_sort(__first, __last, __comp);
+      }
+# endif
 
       typedef _Temporary_buffer<_RandomAccessIterator, _ValueType> _TmpBuf;
       // __stable_sort_adaptive sorts the range in two halves,