mirror of
https://github.com/Neargye/magic_enum.git
synced 2026-01-09 23:34:23 +00:00
362 lines
11 KiB
Markdown
362 lines
11 KiB
Markdown
[](https://github.com/Neargye/magic_enum/releases)
|
|
[](https://conan.io/center/recipes/magic_enum)
|
|
[](https://github.com/microsoft/vcpkg/tree/master/ports/magic-enum)
|
|
[](https://www.cppget.org/magic_enum?q=magic_enum)
|
|
[](https://github.com/mesonbuild/wrapdb/blob/master/subprojects/magic_enum.wrap)
|
|
[](LICENSE)
|
|
[](https://godbolt.org/z/feqcPa5G6)
|
|
[](https://securityscorecards.dev/viewer/?uri=github.com/Neargye/magic_enum)
|
|
[](https://stand-with-ukraine.pp.ua)
|
|
|
|
# Magic Enum C++
|
|
|
|
Header-only C++17 library provides static reflection for enums, work with any enum type without any macro or boilerplate code.
|
|
|
|
If you like this project, please consider donating to one of the funds that help victims of the war in Ukraine: https://u24.gov.ua.
|
|
|
|
## Documentation
|
|
|
|
* [Reference](doc/reference.md)
|
|
* [Limitations](doc/limitations.md)
|
|
* [Integration](#Integration)
|
|
|
|
## [Features & Examples](example/)
|
|
|
|
* Basic
|
|
|
|
```cpp
|
|
#include <magic_enum/magic_enum.hpp>
|
|
#include <iostream>
|
|
|
|
enum class Color { RED = -10, BLUE = 0, GREEN = 10 };
|
|
|
|
int main() {
|
|
Color c1 = Color::RED;
|
|
std::cout << magic_enum::enum_name(c1) << std::endl; // RED
|
|
return 0;
|
|
}
|
|
```
|
|
|
|
* Enum value to string
|
|
|
|
```cpp
|
|
Color color = Color::RED;
|
|
auto color_name = magic_enum::enum_name(color);
|
|
// color_name -> "RED"
|
|
```
|
|
|
|
* String to enum value
|
|
|
|
```cpp
|
|
std::string color_name{"GREEN"};
|
|
auto color = magic_enum::enum_cast<Color>(color_name);
|
|
if (color.has_value()) {
|
|
// color.value() -> Color::GREEN
|
|
}
|
|
|
|
// case insensitive enum_cast
|
|
auto color = magic_enum::enum_cast<Color>(value, magic_enum::case_insensitive);
|
|
|
|
// enum_cast with BinaryPredicate
|
|
auto color = magic_enum::enum_cast<Color>(value, [](char lhs, char rhs) { return std::tolower(lhs) == std::tolower(rhs); }
|
|
|
|
// enum_cast with default
|
|
auto color_or_default = magic_enum::enum_cast<Color>(value).value_or(Color::NONE);
|
|
```
|
|
|
|
* Integer to enum value
|
|
|
|
```cpp
|
|
int color_integer = 2;
|
|
auto color = magic_enum::enum_cast<Color>(color_integer);
|
|
if (color.has_value()) {
|
|
// color.value() -> Color::BLUE
|
|
}
|
|
|
|
auto color_or_default = magic_enum::enum_cast<Color>(value).value_or(Color::NONE);
|
|
```
|
|
|
|
* Indexed access to enum value
|
|
|
|
```cpp
|
|
std::size_t i = 0;
|
|
Color color = magic_enum::enum_value<Color>(i);
|
|
// color -> Color::RED
|
|
```
|
|
|
|
* Enum value sequence
|
|
|
|
```cpp
|
|
constexpr auto colors = magic_enum::enum_values<Color>();
|
|
// colors -> {Color::RED, Color::BLUE, Color::GREEN}
|
|
// colors[0] -> Color::RED
|
|
```
|
|
|
|
* Number of enum elements
|
|
|
|
```cpp
|
|
constexpr std::size_t color_count = magic_enum::enum_count<Color>();
|
|
// color_count -> 3
|
|
```
|
|
|
|
* Enum value to integer
|
|
|
|
```cpp
|
|
Color color = Color::RED;
|
|
auto color_integer = magic_enum::enum_integer(color); // or magic_enum::enum_underlying(color);
|
|
// color_integer -> 1
|
|
```
|
|
|
|
* Enum names sequence
|
|
|
|
```cpp
|
|
constexpr auto color_names = magic_enum::enum_names<Color>();
|
|
// color_names -> {"RED", "BLUE", "GREEN"}
|
|
// color_names[0] -> "RED"
|
|
```
|
|
|
|
* Enum entries sequence
|
|
|
|
```cpp
|
|
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"
|
|
```
|
|
|
|
* Enum fusion for multi-level switch/case statements
|
|
|
|
```cpp
|
|
switch (magic_enum::enum_fuse(color, direction).value()) {
|
|
case magic_enum::enum_fuse(Color::RED, Directions::Up).value(): // ...
|
|
case magic_enum::enum_fuse(Color::BLUE, Directions::Down).value(): // ...
|
|
// ...
|
|
}
|
|
```
|
|
|
|
* Enum switch runtime value as constexpr constant
|
|
```cpp
|
|
Color color = Color::RED;
|
|
magic_enum::enum_switch([] (auto val) {
|
|
constexpr Color c_color = val;
|
|
// ...
|
|
}, color);
|
|
```
|
|
|
|
* Enum iterate for each enum as constexpr constant
|
|
```cpp
|
|
magic_enum::enum_for_each<Color>([] (auto val) {
|
|
constexpr Color c_color = val;
|
|
// ...
|
|
});
|
|
```
|
|
|
|
* Check if enum contains
|
|
|
|
```cpp
|
|
magic_enum::enum_contains(Color::GREEN); // -> true
|
|
magic_enum::enum_contains<Color>(2); // -> true
|
|
magic_enum::enum_contains<Color>(123); // -> false
|
|
magic_enum::enum_contains<Color>("GREEN"); // -> true
|
|
magic_enum::enum_contains<Color>("fda"); // -> false
|
|
```
|
|
|
|
* Enum index in sequence
|
|
|
|
```cpp
|
|
constexpr auto color_index = magic_enum::enum_index(Color::BLUE);
|
|
// color_index.value() -> 1
|
|
// color_index.has_value() -> true
|
|
```
|
|
|
|
* Functions for flags
|
|
|
|
```cpp
|
|
enum Directions : std::uint64_t {
|
|
Left = 1,
|
|
Down = 2,
|
|
Up = 4,
|
|
Right = 8,
|
|
};
|
|
template <>
|
|
struct magic_enum::customize::enum_range<Directions> {
|
|
static constexpr bool is_flags = true;
|
|
};
|
|
|
|
magic_enum::enum_flags_name(Directions::Up | Directions::Right); // -> "Directions::Up|Directions::Right"
|
|
magic_enum::enum_flags_contains(Directions::Up | Directions::Right); // -> true
|
|
magic_enum::enum_flags_cast(3); // -> "Directions::Left|Directions::Down"
|
|
```
|
|
|
|
* Enum type name
|
|
|
|
```cpp
|
|
Color color = Color::RED;
|
|
auto type_name = magic_enum::enum_type_name<decltype(color)>();
|
|
// type_name -> "Color"
|
|
```
|
|
|
|
* IOstream operator for enum
|
|
|
|
```cpp
|
|
using magic_enum::iostream_operators::operator<<; // out-of-the-box ostream operators for enums.
|
|
Color color = Color::BLUE;
|
|
std::cout << color << std::endl; // "BLUE"
|
|
```
|
|
|
|
```cpp
|
|
using magic_enum::iostream_operators::operator>>; // out-of-the-box istream operators for enums.
|
|
Color color;
|
|
std::cin >> color;
|
|
```
|
|
|
|
* Bitwise operator for enum
|
|
|
|
```cpp
|
|
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](https://en.cppreference.com/w/cpp/language/enum#Unscoped_enumeration).
|
|
|
|
```cpp
|
|
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](https://en.cppreference.com/w/cpp/language/enum#Scoped_enumerations).
|
|
|
|
```cpp
|
|
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](doc/limitations.md).
|
|
|
|
```cpp
|
|
constexpr Color color = Color::BLUE;
|
|
constexpr auto color_name = magic_enum::enum_name<color>();
|
|
// color_name -> "BLUE"
|
|
```
|
|
|
|
* `containers::array` array container for enums.
|
|
|
|
```cpp
|
|
magic_enum::containers::array<Color, RGB> color_rgb_array {};
|
|
color_rgb_array[Color::RED] = {255, 0, 0};
|
|
color_rgb_array[Color::GREEN] = {0, 255, 0};
|
|
color_rgb_array[Color::BLUE] = {0, 0, 255};
|
|
magic_enum::containers::get<Color::BLUE>(color_rgb_array) // -> RGB{0, 0, 255}
|
|
```
|
|
|
|
* `containers::bitset` bitset container for enums.
|
|
|
|
```cpp
|
|
constexpr magic_enum::containers::bitset<Color> color_bitset_red_green {Color::RED|Color::GREEN};
|
|
bool all = color_bitset_red_green.all();
|
|
// all -> false
|
|
// Color::BLUE is missing
|
|
bool test = color_bitset_red_green.test(Color::RED);
|
|
// test -> true
|
|
```
|
|
|
|
* `containers::set` set container for enums.
|
|
|
|
```cpp
|
|
auto color_set = magic_enum::containers::set<Color>();
|
|
bool empty = color_set.empty();
|
|
// empty -> true
|
|
color_set.insert(Color::GREEN);
|
|
color_set.insert(Color::BLUE);
|
|
color_set.insert(Color::RED);
|
|
std::size_t size = color_set.size();
|
|
// size -> 3
|
|
```
|
|
|
|
* Improved UB-free "SFINAE-friendly" [underlying_type](https://en.cppreference.com/w/cpp/types/underlying_type).
|
|
|
|
```cpp
|
|
magic_enum::underlying_type<color>::type -> int
|
|
|
|
// Helper types.
|
|
magic_enum::underlying_type_t<Direction> -> int
|
|
```
|
|
## Remarks
|
|
|
|
* `magic_enum` does not pretend to be a silver bullet for reflection for enums, it was originally designed for small enum.
|
|
|
|
* Before use, read the [limitations](doc/limitations.md) of functionality.
|
|
|
|
## Integration
|
|
|
|
* You should add the required file [magic_enum.hpp](include/magic_enum/magic_enum.hpp), and optionally other headers from [include dir](include/) or [release archive](https://github.com/Neargye/magic_enum/releases/latest). Alternatively, you can build the library with CMake.
|
|
|
|
* If you are using [vcpkg](https://github.com/Microsoft/vcpkg/) on your project for external dependencies, then you can use the [magic-enum package](https://github.com/microsoft/vcpkg/tree/master/ports/magic-enum).
|
|
|
|
* If you are using [Conan](https://www.conan.io/) to manage your dependencies, merely add `magic_enum/x.y.z` to your conan's requires, where `x.y.z` is the release version you want to use.
|
|
|
|
* If you are using [Build2](https://build2.org/) to build and manage your dependencies, add `depends: magic_enum ^x.y.z` to the manifest file where `x.y.z` is the release version you want to use. You can then import the target using `magic_enum%lib{magic_enum}`.
|
|
|
|
* Alternatively, you can use something like [CPM](https://github.com/TheLartians/CPM) which is based on CMake's `Fetch_Content` module.
|
|
|
|
```cmake
|
|
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>`.)
|
|
|
|
* If you are using [Ros](https://www.ros.org/), you can include this package by adding `<depend>magic_enum</depend>` to your package.xml and include this package in your workspace. In your CMakeLists.txt add the following:
|
|
```cmake
|
|
find_package(magic_enum CONFIG REQUIRED)
|
|
...
|
|
target_link_libraries(your_executable magic_enum::magic_enum)
|
|
```
|
|
|
|
## Compiler compatibility
|
|
|
|
* Clang/LLVM >= 5
|
|
* MSVC++ >= 14.11 / Visual Studio >= 2017
|
|
* Xcode >= 10
|
|
* GCC >= 9
|
|
* MinGW >= 9
|
|
|
|
## Licensed under the [MIT License](LICENSE)
|