enum_flags limitation? about magic_enum HOT 4 CLOSED

Hi,

MAGIC_ENUM_RANGE_MAX does not affect the maximum amount of flags.

enum_flags_* сhecks all 1<<(1 ... bit_count<Enum>) // bit_count = CHAR_BIT * sizeof(Enum)
but the limitation is that it doesn't check logical AND and '0' not сhecks

Example

enum class TestEnum {
A = 0,
B = 1,
C = 2,
D = 3,
E = 8192
};

enum_count<TestEnum>() = 4;
// '' - mean enmpty string
enum_name(TestEnum::A) = 'A'; vs enum_flags_name(TestEnum::A) = '';
enum_name(TestEnum::B) = 'B'; vs enum_flags_name(TestEnum::B) = 'B';
enum_name(TestEnum::C) = 'C'; vs enum_flags_name(TestEnum::C) = 'C';
enum_name(TestEnum::D) = 'D'; vs enum_flags_name(TestEnum::D) = 'B|C';
enum_name(TestEnum::E) = '';  vs enum_flags_name(TestEnum::E) = 'E';

enum_flags_cast('A') = nullopt; vs enum_cast('A') = TestEnum::A;
enum_flags_cast('D') = nullopt; vs enum_flags_cast('B|C') = TestEnum::D; vs  enum_cast('D') = TestEnum::D;

from magic_enum.

Hi @Neargye, about the zero not being included in the flags for me that's really not an issue. I mostly use magic_enum to generate UI to edit flags and the none/all cases are handled by my ImGui control anyway so I never put the 0 value in my enum flags. This is also how engines like e.g. Unity deal with C# enum flags so I got used to have MyEnum val = (MyEnum)0 instead of having a MyEnum::None entry in the enum flags.

from magic_enum.

I'll add a documentation update later.

from magic_enum.

@Benualdo could you tell me what you think about the restriction that zero is not included in the flags? #321

from magic_enum.