nadult / fwk_enum

Improved C++14 enum class with iteration and conversion to strings

fwk::enum ?

It's a header-only C++17 library with an improved enum class. Features:

• ability to iterate over, enumerate in a range-for and count all elements
• type-safe bitwise operations support without any additional code
• conversion to / from strings (const char*)
• no weirdness, you can use it just like you would use enum class
• VERY lightweight: less than 300 lines of code in a single header file
• decent compilation speed and low runtime overhead
• enums safe to use in switches (assuming decent compiler)
• no dependencies

For more goodness (including EnumMap) have a look at libfwk:
https://github.com/nadult/libfwk

Requirements

• compiler with C++17 support (Clang 4 or GCC 7.1)

Limitations

• you cannot specify custom values for each enum
• you cannot define enums within class or function scope
• number of enum elements is limited to 64

Examples

FWK_ENUM(MyEnum, item_one, item_two, item_three, item_four);

fromString<MyEnum>("item_two") == MyEnum::item_two
fromString<MyEnum>("not an item").valid() == false
string("item_three") == toString(MyEnum::item_three)

string text;
for(auto elem : all<MyEnum>())
	text = text + toString(elem) + " ";

// Cyclic iteration over enum values
next(MyEnum::item_four) == MyEnum::item_one
prev(MyEnum::item_three) == MyEnum::item_two

// It's better to use EnumMap from libfwk instead: it's just as fast
// and it provides some compile and run time checks
int values[count<MyOtherEnum>()] = {1, 2, 3, 4, 5};

for(auto elem : all<MyOtherEnum>())
	cout << elem << ": " << values[(int)elem] << endl;

// Flag operations work out of the box:
flags1 = MyEnum::item_one | MyEnum::item_two | MyEnum::item_three;
flags1 == ~MyEnum::item_four
flags1.bits == 1 + 2 + 4
flag(MyEnum::item_four).bits == 8

// MyFlags uses unsigned char as underlying type because MyEnum has only 4 elements
using MyFlags = EnumFlags<MyEnum>;

MyFlags flags = flags1 ^ MyEnum::item_one;

License

fwk::enum is distributed under the terms of Boost Software License (version 1.0).
See license.txt for details.