add fmt support

.github/workflows/macos.yml

@@ -6,7 +6,7 @@ permissions: read-all
 
 jobs:
   build:
-    runs-on: ${{matrix.config.os}}
+    runs-on: ${{ matrix.config.os }}
     strategy:
       fail-fast: false
       matrix:
@@ -14,7 +14,7 @@ jobs:
         - { os: macos-11  } # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-11-Readme.md#xcode
         - { os: macos-12 } # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-12-Readme.md#xcode
 
-    name: "${{matrix.config.os}}"
+    name: "${{ matrix.config.os }}"
     steps:
     - uses: actions/checkout@v3
 

.github/workflows/ubuntu.yml

@@ -32,7 +32,7 @@ jobs:
 
     - name: Configure clang
       run: |
-        if [[ "${{matrix.compiler.cc}}" == "clang"* ]]; then
+        if [[ "${{ matrix.compiler.cc }}" == "clang"* ]]; then
           wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
           sudo apt-add-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-9 main"
           sudo apt-add-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main"
@@ -44,15 +44,15 @@ jobs:
           sudo apt-add-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-16 main"
           sudo apt-add-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal main"
           sudo apt update
-          sudo apt install ${{matrix.compiler.cc}} -y
+          sudo apt install ${{ matrix.compiler.cc }} -y
         fi
 
     - name: Configure gcc
       run: |
-        if [[ "${{matrix.compiler.cc}}" == "gcc"* ]]; then
+        if [[ "${{ matrix.compiler.cc }}" == "gcc"* ]]; then
           sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
           sudo apt update
-          sudo apt install ${{matrix.compiler.cxx}} -y
+          sudo apt install ${{ matrix.compiler.cxx }} -y
         fi
 
     - name: Build Release
@@ -60,7 +60,7 @@ jobs:
         rm -rf build
         mkdir build
         cd build
-        cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_COMPILER=${{matrix.compiler.cxx}} -DMAGIC_ENUM_OPT_ENABLE_NONASCII:BOOL=${{matrix.compiler.nonascii}}
+        cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_COMPILER=${{ matrix.compiler.cxx }} -DMAGIC_ENUM_OPT_ENABLE_NONASCII:BOOL=${{ matrix.compiler.nonascii }}
         cmake --build . -j 4 --config Release
         ctest --output-on-failure -C Release
 
@@ -69,7 +69,7 @@ jobs:
         rm -rf build
         mkdir build
         cd build
-        cmake .. -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER=${{matrix.compiler.cxx}} -DMAGIC_ENUM_OPT_ENABLE_NONASCII:BOOL=${{matrix.compiler.nonascii}}
+        cmake .. -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER=${{ matrix.compiler.cxx }} -DMAGIC_ENUM_OPT_ENABLE_NONASCII:BOOL=${{ matrix.compiler.nonascii }}
         cmake --build . -j 4 --config Debug
         ctest --output-on-failure -C Debug
 

.github/workflows/windows.yml

@@ -6,7 +6,7 @@ permissions: read-all
 
 jobs:
   build:
-    runs-on: ${{matrix.config.os}}
+    runs-on: ${{ matrix.config.os }}
     strategy:
       fail-fast: false
       matrix:

include/magic_enum_format.hpp

@@ -32,14 +32,10 @@
 #ifndef NEARGYE_MAGIC_ENUM_FORMAT_HPP
 #define NEARGYE_MAGIC_ENUM_FORMAT_HPP
 
-#if !defined(__cpp_lib_format)
-#  error "Format is not supported"
-#endif
-
 #include "magic_enum.hpp"
 
 #if !defined(MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT)
-#  define MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT true
+#  define MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT 1
 #  define MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT_AUTO_DEFINE
 #endif // MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT
 
@@ -51,23 +47,48 @@ namespace magic_enum::customize {
   }
 } // magic_enum::customize
 
+#if defined(__cpp_lib_format)
+
 #include <format>
 
 template <typename E>
-struct std::formatter<E, std::enable_if_t<std::is_enum_v<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>> && magic_enum::customize::enum_format_enabled<E>(), char>> : std::formatter<std::string_view, char> {
   auto format(E e, format_context& 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 (const auto name = magic_enum::enum_name<D, magic_enum::as_flags<magic_enum::detail::is_flags_v<D>>>(e); !name.empty()) {
-        return std::formatter<std::string_view, char>::format(std::string_view{name.data(), name.size()}, ctx);
+        return formatter<std::string_view, char>::format(std::string_view{name.data(), name.size()}, ctx);
       }
     }
-    return std::formatter<std::string_view, char>::format(std::to_string(magic_enum::enum_integer<D>(e)), ctx);
+    return formatter<std::string_view, char>::format(std::to_string(magic_enum::enum_integer<D>(e)), ctx);
   }
 };
 
+#endif // MAGIC_ENUM_DEFAULT_ENABLE_ENUM_FORMAT
+
+#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, char> {
+  auto format(E e, format_context& ctx) {
+    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 (const auto name = magic_enum::enum_name<D, magic_enum::as_flags<magic_enum::detail::is_flags_v<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);
+  }
+};
+
+#endif // FMT_VERSION
+
 #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

test/CMakeLists.txt

@@ -47,7 +47,6 @@ if(MAGIC_ENUM_OPT_ENABLE_NONASCII)
     make_test(test_nonascii.cpp test_nonascii-cpp17 c++17)
 endif()
 
-
 if(HAS_CPP20_FLAG)
     make_test(test.cpp test-cpp20 c++20)
     make_test(test_flags.cpp test_flags-cpp20 c++20)

test/test.cpp

@@ -128,13 +128,11 @@ TEST_CASE("enum_cast") {
     REQUIRE(enum_cast<Directions>("Left").value() == Directions::Left);
     REQUIRE_FALSE(enum_cast<Directions>("None").has_value());
 
-#if !defined(MAGIC_ENUM_ENABLE_NONASCII)
     constexpr auto dr2 = enum_cast<Directions>("RIGHT", case_insensitive);
     REQUIRE(dr2.value() == Directions::Right);
     REQUIRE(enum_cast<Directions&>("up", case_insensitive).value() == Directions::Up);
     REQUIRE(enum_cast<const Directions>("dOwN", case_insensitive).value() == Directions::Down);
     REQUIRE_FALSE(enum_cast<Directions>("Left-", case_insensitive).has_value());
-#endif
 
     constexpr auto nt = enum_cast<number>("three");
     REQUIRE(enum_cast<number>("one").value() == number::one);
@@ -350,13 +348,11 @@ TEST_CASE("enum_contains") {
     REQUIRE(enum_contains<Directions>("Left"));
     REQUIRE_FALSE(enum_contains<Directions>("None"));
 
-#if !defined(MAGIC_ENUM_ENABLE_NONASCII)
     auto dr2 = std::string{"RIGHT"};
     REQUIRE(enum_contains<const Directions>(dr2, case_insensitive));
     REQUIRE(enum_contains<Directions&>("up", case_insensitive));
     REQUIRE(enum_contains<Directions>("dOwN", case_insensitive));
     REQUIRE_FALSE(enum_contains<Directions>("Left-", case_insensitive));
-#endif
 
     constexpr auto nt = enum_contains<number>("three");
     REQUIRE(enum_contains<number>("one"));
@@ -1018,7 +1014,6 @@ TEST_CASE("multdimensional-switch-case") {
 TEST_CASE("format-base") {
   REQUIRE(std::format("{}", Color::RED) == "red");
   REQUIRE(std::format("{}", Color{0}) == "0");
-  REQUIRE(std::format("Test-{:~^10}.", Color::RED) == "Test-~~~red~~~~.");
 }
 
 #endif