Workaround ABI incompatibility between clang ang gcc

2025-10-18 07:39:31 -07:00
parent 85f6ecc7a0
commit e2aa06cd0a
2 changed files with 5 additions and 2 deletions
--- a/include/fmt/base.h
+++ b/include/fmt/base.h
@@ -924,7 +924,10 @@ class locale_ref {
  constexpr locale_ref() : locale_(nullptr) {}

  template <typename Locale, FMT_ENABLE_IF(sizeof(Locale::collate) != 0)>
-  locale_ref(const Locale& loc);
+  locale_ref(const Locale& loc) : locale_(&loc) {
+    // Check if std::isalpha is found via ADL to reduce the chance of misuse.
+    isalpha('x', loc);
+  }

  inline explicit operator bool() const noexcept { return locale_ != nullptr; }
 #endif  // FMT_USE_LOCALE