__  __             _        ______                          _____
|  \/  |           (_)      |  ____|                        / ____|_     _
| \  / | __ _  __ _ _  ___  | |__   _ __  _   _ _ __ ___   | |   _| |_ _| |_
| |\/| |/ _` |/ _` | |/ __| |  __| | '_ \| | | | '_ ` _ \  | |  |_   _|_   _|
| |  | | (_| | (_| | | (__  | |____| | | | |_| | | | | | | | |____|_|   |_|
|_|  |_|\__,_|\__, |_|\___| |______|_| |_|\__,_|_| |_| |_|  \_____|
               __/ |
              |___/

Magic Enum C++

Header-only C++17 library provides static reflection for enums, work with any enum type without any macro or boilerplate code.

• enum_cast obtains enum value from string or integer.
• enum_value returns enum value at specified index.
• enum_values obtains enum value sequence.
• enum_count returns number of enum values.
• enum_integer obtains integer value from enum value.
• enum_name returns string name from enum value.
• enum_names obtains string enum name sequence.
• enum_entries obtains pair (value enum, string enum name) sequence.
• enum_index obtains index in enum value sequence from enum value.
• is_unscoped_enum checks whether type is an Unscoped enumeration.
• is_scoped_enum checks whether type is an Scoped enumeration.
• underlying_type improved UB-free "SFINAE-friendly" std::underlying_type.
• using namespace magic_enum::ostream_operators; ostream operators for enums.
• using namespace magic_enum::bitwise_operators; bitwise operators for enums.

Features

• C++17
• Header-only
• Dependency-free
• Compile-time
• Enum to string
• String to enum
• Iterating over enum

Examples

// For example color enum.
enum Color { RED = 2, BLUE = 4, GREEN = 8 };

• Enum value to string

  Color color = Color::RED;
  auto color_name = magic_enum::enum_name(color);
  // color_name -> "RED"
  

• String to enum value

  std::string color_name{"GREEN"};
  auto color = magic_enum::enum_cast<Color>(color_name);
  if (color.has_value()) {
    // color.value() -> Color::GREEN
  }
  

• Integer to enum value

  int color_integer = 2;
  auto color = magic_enum::enum_cast<Color>(color_integer);
  if (colo.has_value()) {
    // color.value() -> Color::RED
  }
  

• Indexed access to enum value

  int i = 1;
  Color color = magic_enum::enum_value<Color>(i);
  // color -> Color::BLUE
  

• Enum value sequence

  constexpr auto colors = magic_enum::enum_values<Color>();
  // colors -> {Color::RED, Color::BLUE, Color::GREEN}
  // colors[0] -> Color::RED
  

• Number of enum elements

  constexpr std::size_t color_count = magic_enum::enum_count<Color>();
  // color_count -> 3
  

• Enum value to integer

  Color color = Color::RED;
  auto color_integer = magic_enum::enum_integer(color);
  // color -> 2
  

• Enum names sequence

  constexpr auto color_names = magic_enum::enum_names<Color>();
  // color_names -> {"RED", "BLUE", "GREEN"}
  // color_names[0] -> "RED"
  

• Enum entries sequence

  constexpr auto color_entries = magic_enum::enum_entries<Color>();
  // color_entries -> {{Color::RED, "RED"}, {Color::BLUE, "BLUE"}, {Color::GREEN, "GREEN"}}
  // color_entries[0].first -> Color::RED
  // color_entries[0].second -> "RED"
  

• Stream operator for enum

  using namespace magic_enum::ostream_operators; // out-of-the-box ostream operators for enums.
  Color color = Color::BLUE;
  std::cout << color << std::endl; // "BLUE"
  

• Bitwise operator for enum

  enum class Flags { A = 1 << 0, B = 1 << 1, C = 1 << 2, D = 1 << 3 };
  using namespace magic_enum::bitwise_operators; // out-of-the-box bitwise operators for enums.
  // Support operators: ~, |, &, ^, |=, &=, ^=.
  Flags flags = Flags::A | Flags::B & ~Flags::C;
  

• Checks whether type is an Unscoped enumeration.

  enum color { red, green, blue };
  enum class direction { left, right };
  
  magic_enum::is_unscoped_enum<color>::value -> true
  magic_enum::is_unscoped_enum<direction>::value -> false
  magic_enum::is_unscoped_enum<int>::value -> false
  
  // Helper variable template.
  magic_enum::is_unscoped_enum_v<color> -> true
  

• Checks whether type is an Scoped enumeration.

  enum color { red, green, blue };
  enum class direction { left, right };
  
  magic_enum::is_scoped_enum<color>::value -> false
  magic_enum::is_scoped_enum<direction>::value -> true
  magic_enum::is_scoped_enum<int>::value -> false
  
  // Helper variable template.
  magic_enum::is_scoped_enum_v<direction> -> true
  

• Static storage enum variable to string This version is much lighter on the compile times and is not restricted to the enum_range limitation.

  constexpr Color color = Color::BLUE;
  constexpr auto color_name = magic_enum::enum_name<color>();
  // color_name -> "BLUE"
  

Remarks

• magic_enum::enum_cast(value) returns std::optional<E>, using has_value() to check contains enum value and value() to get the enum value.

• magic_enum::enum_value(index) no bounds checking is performed: the behavior is undefined if index >= number of enum values.

• magic_enum::enum_values<E>() returns std::array<E, N> with all enum value where N = number of enum values, sorted by enum value.

• magic_enum::enum_name(value) returns std::string_view. If enum value does not have name, returns empty string.

• magic_enum::enum_name<value>() is much lighter on the compile times and is not restricted to the enum_range limitation.

• magic_enum::enum_names<E>() returns std::array<std::string_view, N> with all string enum name where N = number of enum values, sorted by enum value.

• magic_enum::enum_entries<E>() returns std::array<std::pair<E, std::string_view>, N> with all std::pair (value enum, string enum name) where N = number of enum values, sorted by enum value.

• Enum value must be in range [MAGIC_ENUM_RANGE_MIN, MAGIC_ENUM_RANGE_MAX]. By default MAGIC_ENUM_RANGE_MIN = -128, MAGIC_ENUM_RANGE_MAX = 128.

  If need another range for all enum types by default, redefine the macro MAGIC_ENUM_RANGE_MIN and MAGIC_ENUM_RANGE_MAX.

  #define MAGIC_ENUM_RANGE_MIN 0
  #define MAGIC_ENUM_RANGE_MAX 256
  #include <magic_enum.hpp>
  

  If need another range for specific enum type, add specialization enum_range for necessary enum type.

  #include <magic_enum.hpp>
  
  enum number { one = 100, two = 200, three = 300 };
  
  namespace magic_enum {
  template <>
  struct enum_range<number> {
    static constexpr int min = 100;
    static constexpr int max = 300;
  };
  }
  

• magic_enum obtains the first defined value enums, and won't work if value are aliased.

  enum ShapeKind {
    ConvexBegin = 0,
    Box = 0, // Won't work.
    Sphere = 1,
    ConvexEnd = 2,
    Donut = 2, // Won't work too.
    Banana = 3,
    COUNT = 4,
  };
  // magic_enum::enum_cast<ShapeKind>("Box") -> std::nullopt
  // magic_enum::enum_name(ShapeKind::Box) -> "ConvexBegin"
  

  Work around the issue:

  enum ShapeKind {
    // Convex shapes, see ConvexBegin and ConvexEnd below.
    Box = 0,
    Sphere = 1,
  
    // Non-convex shapes.
    Donut = 2,
    Banana = 3,
  
    COUNT = Banana + 1,
  
    // Non-reflected aliases.
    ConvexBegin = Box,
    ConvexEnd = Sphere + 1,
  };
  // magic_enum::enum_cast<ShapeKind>("Box") -> ShapeKind::Box
  // magic_enum::enum_name(ShapeKind::Box) -> "Box"
  
  // Non-reflected aliases.
  // magic_enum::enum_cast<ShapeKind>("ConvexBegin") -> std::nullopt
  // magic_enum::enum_name(ShapeKind::ConvexBegin) -> "Box"
  

Integration

You should add the required file magic_enum.hpp.

If you are using vcpkg on your project for external dependencies, then you can use the magic_enum package.

If you are using Conan to manage your dependencies, merely add magic_enum/x.y.z@neargye/stable to your conan's requires, where x.y.z is the release version you want to use.

Compiler compatibility

• Clang/LLVM >= 5
• Visual C++ >= 15.3 / Visual Studio >= 2017
• Xcode >= 10.2
• GCC >= 9

Licensed under the MIT License