From c57813043ee2084d6887338fbb09879a4e485cf8 Mon Sep 17 00:00:00 2001
From: Enrico Seiler <enrico.seiler@hotmail.de>
Date: Sat, 28 Feb 2026 18:47:17 +0100
Subject: [PATCH] fix(llvm): charconv on apple

This is a nasty workaround. Ideally, there should be a seqan::stl::from_chars.
---
 .clang-format                         |  6 +++++-
 include/seqan3/std/charconv           | 17 ++++++++++++++++-
 test/unit/std/charconv_float_test.cpp |  2 +-
 test/unit/std/charconv_int_test.cpp   |  2 +-
 4 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/.clang-format b/.clang-format
index f27353b3ef..5a57292110 100644
--- a/.clang-format
+++ b/.clang-format
@@ -124,9 +124,13 @@ IncludeCategories:
     Priority:        1
     SortPriority:    0
     CaseSensitive:   false
+  - Regex:           '(<seqan3/std/charconv>)'
+    Priority:        2
+    SortPriority:    1
+    CaseSensitive:   false
   - Regex:           '(<[[:alnum:]._]+>|<seqan3/std/.*>)'
     Priority:        2
-    SortPriority:    0
+    SortPriority:    2
     CaseSensitive:   false
   - Regex:           '<sdsl/'
     Priority:        3
diff --git a/include/seqan3/std/charconv b/include/seqan3/std/charconv
index fca8f5ee6f..de089f773e 100644
--- a/include/seqan3/std/charconv
+++ b/include/seqan3/std/charconv
@@ -11,9 +11,24 @@
 #ifndef SEQAN_STD_CHARCONV_SHIM
 #define SEQAN_STD_CHARCONV_SHIM
 
+#include <version> // From C++20 onwards, all feature macros should be defined here.
+
+// Workaround for llvm marking float charconv as unavailable
+#if defined(__APPLE__) && defined(_LIBCPP_VERSION)
+#    ifdef _LIBCPP___CHARCONV_FROM_CHARS_FLOATING_POINT_H
+#        warning This file needs to be included before any <charconv> include.
+#    endif
+#    if __has_include(<__configuration/availability.h>)
+#        include <__configuration/availability.h>
+#        undef _LIBCPP_AVAILABILITY_FROM_CHARS_FLOATING_POINT
+#        define _LIBCPP_AVAILABILITY_FROM_CHARS_FLOATING_POINT /* nothing */
+#        undef _LIBCPP_AVAILABILITY_HAS_FROM_CHARS_FLOATING_POINT
+#        define _LIBCPP_AVAILABILITY_HAS_FROM_CHARS_FLOATING_POINT /* nothing */
+#    endif
+#endif
+
 #include <charconv>
 #include <utility> // __cpp_lib_to_chars may be defined here as currently documented.
-#include <version> // From C++20 onwards, all feature macros should be defined here.
 
 /*!\defgroup std_charconv charconv
  * \ingroup std
diff --git a/test/unit/std/charconv_float_test.cpp b/test/unit/std/charconv_float_test.cpp
index 8396afe0f4..53411e49f2 100644
--- a/test/unit/std/charconv_float_test.cpp
+++ b/test/unit/std/charconv_float_test.cpp
@@ -6,12 +6,12 @@
 
 // make sure that including the std header does not produce any errors
 // see https://github.com/seqan/seqan3/issues/2352
+#include <seqan3/std/charconv>
 #include <charconv>
 #include <cmath>
 #include <concepts>
 #include <iostream>
 #include <limits>
-#include <seqan3/std/charconv>
 
 // =============================================================================
 // std::from_chars for float, double and long double
diff --git a/test/unit/std/charconv_int_test.cpp b/test/unit/std/charconv_int_test.cpp
index ba9a02ddb3..99c9d75fd6 100644
--- a/test/unit/std/charconv_int_test.cpp
+++ b/test/unit/std/charconv_int_test.cpp
@@ -6,12 +6,12 @@
 
 // make sure that including the std header does not produce any errors
 // see https://github.com/seqan/seqan3/issues/2352
+#include <seqan3/std/charconv>
 #include <charconv>
 #include <cmath>
 #include <concepts>
 #include <iostream>
 #include <limits>
-#include <seqan3/std/charconv>
 
 // =============================================================================
 // std::from_chars for integral types