typedef NS_ENUM(NSInteger, Mytype)
{
kValue1 = 1,
kValue2 = 2,
kValue3 = 3,
kValue4 = 4,
};
STRING_ENUM(SType2,
kStringValue0,
kStringValue1,
kStringValue2,
kStringValue3);
automatic string-value from name: name == X, value == @"X"