From ff6e5dd1c82a0c8cf8f774759933cc0a353fa5f9 Mon Sep 17 00:00:00 2001
From: Daniil Goncharov <neargye@gmail.com>
Date: Thu, 20 Feb 2025 12:37:47 +0400
Subject: [PATCH] fix 379 (#382)

---
 include/magic_enum/magic_enum_format.hpp | 78 ++++++++----------------
 test/test.cpp                            |  1 +
 2 files changed, 25 insertions(+), 54 deletions(-)

diff --git a/include/magic_enum/magic_enum_format.hpp b/include/magic_enum/magic_enum_format.hpp
index 499758942..eadceecbb 100644
--- a/include/magic_enum/magic_enum_format.hpp
+++ b/include/magic_enum/magic_enum_format.hpp
@@ -35,44 +35,35 @@
 #include "magic_enum.hpp"
 #include "magic_enum_flags.hpp"
 
-#if !defined(MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT)
-#  define MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT 1
-#  define MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT_AUTO_DEFINE
-#endif
-
-namespace magic_enum::customize {
-  // customize enum to enable/disable automatic std::format
-  template <typename E>
-  constexpr bool enum_format_enabled() noexcept {
-    return MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT;
+namespace magic_enum::detail {
+
+template <typename E, std::enable_if_t<std::is_enum_v<std::decay_t<E>>, int> = 0>
+std::string format_as(E e) {
+  using D = std::decay_t<E>;
+  static_assert(std::is_same_v<char, magic_enum::string_view::value_type>, "magic_enum::formatter requires string_view::value_type type same as char.");
+  if constexpr (magic_enum::detail::supported<D>::value) {
+    if constexpr (magic_enum::detail::subtype_v<D> == magic_enum::detail::enum_subtype::flags) {
+      if (const auto name = magic_enum::enum_flags_name<D>(e); !name.empty()) {
+        return {name.data(), name.size()};
+      }
+    } else {
+      if (const auto name = magic_enum::enum_name<D>(e); !name.empty()) {
+        return {name.data(), name.size()};
+      }
+    }
   }
-} // magic_enum::customize
+  return std::to_string(magic_enum::enum_integer<D>(e));
+}
 
-#if defined(__cpp_lib_format)
+} // namespace magic_enum::format
 
-#ifndef MAGIC_ENUM_USE_STD_MODULE
-#include <format>
-#endif
+#if defined(__cpp_lib_format)
 
 template <typename E>
-struct std::formatter<E, std::enable_if_t<std::is_enum_v<std::decay_t<E>> && magic_enum::customize::enum_format_enabled<E>(), char>> : std::formatter<std::string_view, char> {
+struct std::formatter<E, std::enable_if_t<std::is_enum_v<std::decay_t<E>>, char>> : std::formatter<std::string_view, char> {
   template <class FormatContext>
   auto format(E e, FormatContext& ctx) const {
-    static_assert(std::is_same_v<char, string_view::value_type>, "formatter requires string_view::value_type type same as char.");
-    using D = std::decay_t<E>;
-
-    if constexpr (magic_enum::detail::supported<D>::value) {
-      if constexpr (magic_enum::detail::subtype_v<D> == magic_enum::detail::enum_subtype::flags) {
-        if (const auto name = magic_enum::enum_flags_name<D>(e); !name.empty()) {
-          return formatter<std::string_view, char>::format(std::string_view{name.data(), name.size()}, ctx);
-        }
-      } else {
-        if (const auto name = magic_enum::enum_name<D>(e); !name.empty()) {
-          return formatter<std::string_view, char>::format(std::string_view{name.data(), name.size()}, ctx);
-        }
-      }
-    }
-    return formatter<std::string_view, char>::format(std::to_string(magic_enum::enum_integer<D>(e)), ctx);
+    return std::formatter<std::string_view, char>::format(magic_enum::detail::format_as<E>(e), ctx);
   }
 };
 
@@ -80,35 +71,14 @@ struct std::formatter<E, std::enable_if_t<std::is_enum_v<std::decay_t<E>> && mag
 
 #if defined(FMT_VERSION)
 
-#include <fmt/format.h>
-
 template <typename E>
-struct fmt::formatter<E, std::enable_if_t<std::is_enum_v<std::decay_t<E>> && magic_enum::customize::enum_format_enabled<E>(), char>> : fmt::formatter<std::string_view> {
+struct fmt::formatter<E, std::enable_if_t<std::is_enum_v<std::decay_t<E>>, char>> : fmt::formatter<std::string_view, char> {
   template <class FormatContext>
   auto format(E e, FormatContext& ctx) const {
-    static_assert(std::is_same_v<char, string_view::value_type>, "formatter requires string_view::value_type type same as char.");
-    using D = std::decay_t<E>;
-
-    if constexpr (magic_enum::detail::supported<D>::value) {
-      if constexpr (magic_enum::detail::subtype_v<D> == magic_enum::detail::enum_subtype::flags) {
-        if (const auto name = magic_enum::enum_flags_name<D>(e); !name.empty()) {
-          return formatter<std::string_view, char>::format(std::string_view{name.data(), name.size()}, ctx);
-        }
-      } else {
-        if (const auto name = magic_enum::enum_name<D>(e); !name.empty()) {
-          return formatter<std::string_view, char>::format(std::string_view{name.data(), name.size()}, ctx);
-        }
-      }
-    }
-    return formatter<std::string_view, char>::format(std::to_string(magic_enum::enum_integer<D>(e)), ctx);
+    return fmt::formatter<std::string_view, char>::format(magic_enum::detail::format_as<E>(e), ctx);
   }
 };
 
 #endif
 
-#if defined(MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT_AUTO_DEFINE)
-#  undef MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT
-#  undef MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT_AUTO_DEFINE
-#endif
-
 #endif // NEARGYE_MAGIC_ENUM_FORMAT_HPP
diff --git a/test/test.cpp b/test/test.cpp
index ef0459dae..9d26eab8b 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -1176,6 +1176,7 @@ TEST_CASE("multdimensional-switch-case") {
 
 #if defined(__cpp_lib_format)
 
+#include <format>
 #include <magic_enum/magic_enum_format.hpp>
 
 TEST_CASE("format-base") {