https://github.com/seleznevae/smart_enum
Smart enums for c++
https://github.com/seleznevae/smart_enum
cpp14
Last synced: about 1 year ago
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Smart enums for c++
- Host: GitHub
- URL: https://github.com/seleznevae/smart_enum
- Owner: seleznevae
- License: mit
- Created: 2017-03-26T09:58:47.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2017-05-06T14:18:02.000Z (about 9 years ago)
- Last Synced: 2025-04-10T01:14:26.797Z (about 1 year ago)
- Topics: cpp14
- Language: C++
- Homepage:
- Size: 909 KB
- Stars: 12
- Watchers: 4
- Forks: 4
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Smart enum
[](https://travis-ci.org/seleznevae/smart_enum)
[](https://opensource.org/licenses/MIT)
- [Design goals](#design-goals)
- [Examples](#examples)
- [License](#license)
Header-only library for compile-time C++ enum introspection.
## Design goals
C++ doesn't have reflection. It is a common technique to use macros to add compile time information about enumeration like the following:
```c++
enum class Animal {
Dog = 1,
Cat = 2,
Lion = 4,
Horse = 5,
};
DECLARE_ENUM(Animal, Animal::Dog, Animal::Cat, Animal::Lion, Animal::Horse);
```
This code violates **DRY** (don't repeat yourself) principle. The aim of **smart enum** library is to provide a user with macros that can be used in enum declaration and the user will not need to repeat enum elements.
## Highlights
1. Smart enums can be declared in namespaces and classes.
2. Smart enum to and from string conversions.
## Examples
Declaration of smart enum looks like this:
```c++
#include "smart_enum.h"
SMART_ENUM(Animal, int) {
SM_ENUM_ELEM(Dog, 1, "dog" , "dog_description");
SM_ENUM_ELEM(Cat, 2, "cat" );
SM_ENUM_ELEM(Lion, 5);
SM_ENUM_ELEM(Horse);
};
```
For each enum constant string representation and string description is generated. When macro with 1 or 2 arguments is used
( like SM_ENUM_ELEM(Lion, 5) and SM_ENUM_ELEM(Horse) ) string representation and description will match enum constant name.
If you want to specify custom string representation and string description macro with 3 or 4 arguments should be used.
Definitions of variables:
```c++
Animal pet_cat ={Animal::Cat};
Animal pet_dog = Animal::Dog;
Animal pet_lion (Animal::Lion);
Animal pet_horse {Animal::Horse};
```
It is possible to convert smart enums to strings:
```c++
std::cout << "pet name: " << pet_cat.to_string() << std::endl;
//pet name: cat
std::cout << "pet name: " << pet_lion.to_string() << std::endl;
//pet name: Lion
```
It is possible get descriptions for smart enum values:
```c++
std::cout << "descr.: " << pet_dog.description() << std::endl;
//descr.: dog_description
std::cout << "descr.: " << pet_horse.description() << std::endl;
//descr.: hOrse
```
Smart enums can be used in switch statements like ordinal enums:
```c++
switch (pet_cat) {
case Animal::Cat:
assert(true);
break;
case Animal::Horse:
assert(false);
break;
default:
assert(false);
break;
}
```
It is possible to get information about number of elements declared in smart enum:
```c++
std::cout << "Elements in smart enum: " << Animal::size() << std::endl;
//Elements in smart enum: 4
```
It is possible to get all values, names and descriptions of smart enum:
```c++
std::cout << "smart enum names: ";
for (const auto &enum_item : Animal::values())
std::cout << enum_item.to_string() << " ";
std::cout << std::endl;
//smart enum names: dog cat Lion Horse
std::cout << "smart enum names: ";
for (const auto &name : Animal::names())
std::cout << name << " ";
std::cout << std::endl;
//smart enum names: dog cat Lion Horse
std::cout << "smart enum descriptions: ";
for (const auto &name : Animal::descriptions())
std::cout << name << " ";
std::cout << std::endl;
//smart enum descriptions: dog_description cat Lion Horse
```
It is possible to check if smart enum value is valid:
```c++
Animal invalid;
*(reinterpret_cast(&invalid)) = 6666;
assert(invalid.is_valid() == false);
```
## Installation
Include smart_enum.h in your source code.
## License
The MIT license