__ __ _ ______ _____
| \/ | (_) | ____| / ____|_ _
| \ / | __ _ __ _ _ ___ | |__ _ __ _ _ _ __ ___ | | _| |_ _| |_
| |\/| |/ _` |/ _` | |/ __| | __| | '_ \| | | | '_ ` _ \ | | |_ _|_ _|
| | | | (_| | (_| | | (__ | |____| | | | |_| | | | | | | | |____|_| |_|
|_| |_|\__,_|\__, |_|\___| |______|_| |_|\__,_|_| |_| |_| \_____|
__/ |
|___/
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_castobtains enum value from string or integer.enum_valuereturns enum value at specified index.enum_valuesobtains enum value sequence.enum_countreturns number of enum values.enum_integerobtains integer value from enum value.enum_namereturns name from enum value.enum_namesobtains string enum name sequence.enum_entriesobtains pair (value enum, string enum name) sequence.enum_indexobtains index in enum value sequence from enum value.enum_containschecks whether enum contains enumerator with such value.enum_type_namereturns name of enum type.is_unscoped_enumchecks whether type is an Unscoped enumeration.is_scoped_enumchecks whether type is an Scoped enumeration.underlying_typeimproved UB-free "SFINAE-friendly" underlying_type.ostream_operatorsostream operators for enums.bitwise_operatorsbitwise operators for enums.
Documentation
Features
- C++17
- Header-only
- Dependency-free
- Compile-time
- Enum to string
- String to enum
- Iterating over enum
Examples
// For example color enum.
enum class Color { RED = 2, BLUE = 4, GREEN = 8 };
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Enum value to string
Color color = Color::RED; auto color_name = magic_enum::enum_name(color); // color_name -> "RED"
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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 (color.has_value()) { // color.value() -> Color::RED }
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Indexed access to enum value
std::size_t i = 1; Color color = magic_enum::enum_value<Color>(i); // color -> Color::BLUE
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Enum value sequence
constexpr auto& colors = magic_enum::enum_values<Color>(); // colors -> {Color::RED, Color::BLUE, Color::GREEN} // colors[0] -> Color::RED
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Number of enum elements
constexpr std::size_t color_count = magic_enum::enum_count<Color>(); // color_count -> 3
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Enum value to integer
Color color = Color::RED; auto color_integer = magic_enum::enum_integer(color); // color -> 2
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Enum names sequence
constexpr auto& color_names = magic_enum::enum_names<Color>(); // color_names -> {"RED", "BLUE", "GREEN"} // color_names[0] -> "RED"
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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"
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Ostream 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"
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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;
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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
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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
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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_enumdoes not pretend to be a silver bullet for reflection for enums, it was originally designed for small enum. -
Before use, read the limitations of functionality.
-
For the small enum use the API from the namespace
magic_enum, and for enum-flags use the API from the namespacemagic_enum::flags.
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.zto your conan's requires, wherex.y.zis the release version you want to use. -
Alternatively, you can use something like CPM which is based on CMake's
Fetch_Contentmodule.CPMAddPackage( NAME magic_enum GITHUB_REPOSITORY Neargye/magic_enum GIT_TAG x.y.z # Where `x.y.z` is the release version you want to use. ) -
Bazel is also supported, simply add to your WORKSPACE file:
http_archive( name = "magic_enum", strip_prefix = "magic_enum-<commit>", urls = ["https://github.com/Neargye/magic_enum/archive/<commit>.zip"], )To use bazel inside the repository it's possible to do:
bazel build //... bazel test //... bazel run //:example(Note that you must use a supported compiler or specify it with
export CC= <compiler>.)
Compiler compatibility
- Clang/LLVM >= 5
- MSVC++ >= 14.11 / Visual Studio >= 2017
- Xcode >= 10
- GCC >= 9
- MinGW >= 9
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