enums

问题 pip install Enum is not working is showing the error of AttributeError:module 'enum' has no attribute 'IntFlag' 回答1: enum34 is the stdlib Enum backport, but it only supports features found up to 3.5. If you want features found in 3.6 you'll need to use aenum 1 . 1 Disclosure: I am the author of the Python stdlib Enum, the enum34 backport, and the Advanced Enumeration (aenum) library. 来源： https://stackoverflow.com/questions/44745374/pip-install-enum-not-working-showing-the-error-of-intflag

问题 pip install Enum is not working is showing the error of AttributeError:module 'enum' has no attribute 'IntFlag' 回答1: enum34 is the stdlib Enum backport, but it only supports features found up to 3.5. If you want features found in 3.6 you'll need to use aenum 1 . 1 Disclosure: I am the author of the Python stdlib Enum, the enum34 backport, and the Advanced Enumeration (aenum) library. 来源： https://stackoverflow.com/questions/44745374/pip-install-enum-not-working-showing-the-error-of-intflag

问题 I have three enum classes. I want to somehow put these in an array, loop through the array and call the same method in each enum class. Is this possible in Java? It seems to me you can't place enum types in an array structure (unless i've missed how). Thank you. 回答1: Let each enum type implement a common interface that has the common method that you want into invoke. You can now cast each enum, while iterating, to this common interface and call the method. Also look at EnumSet 回答2: Here is an

问题 I have three enum classes. I want to somehow put these in an array, loop through the array and call the same method in each enum class. Is this possible in Java? It seems to me you can't place enum types in an array structure (unless i've missed how). Thank you. 回答1: Let each enum type implement a common interface that has the common method that you want into invoke. You can now cast each enum, while iterating, to this common interface and call the method. Also look at EnumSet 回答2: Here is an

问题 I have a TypeScript code snippet in the playground. Please take a look there at TypeScript playground or here: enum MyTypes { FIRST = "FIRST", SECOND = "SECOND", THIRD = "THIRD" } type TFirst = { type: MyTypes.FIRST foo: string } type TSecond = { type: MyTypes.SECOND foo: string } type TThird = { type: MyTypes.THIRD bar: string } type TConditionalType<T> = T extends MyTypes.FIRST ? TFirst : T extends MyTypes.SECOND ? TSecond : T extends MyTypes.THIRD ? TThird : null const

问题 I have a TypeScript code snippet in the playground. Please take a look there at TypeScript playground or here: enum MyTypes { FIRST = "FIRST", SECOND = "SECOND", THIRD = "THIRD" } type TFirst = { type: MyTypes.FIRST foo: string } type TSecond = { type: MyTypes.SECOND foo: string } type TThird = { type: MyTypes.THIRD bar: string } type TConditionalType<T> = T extends MyTypes.FIRST ? TFirst : T extends MyTypes.SECOND ? TSecond : T extends MyTypes.THIRD ? TThird : null const

问题 I have a TypeScript code snippet in the playground. Please take a look there at TypeScript playground or here: enum MyTypes { FIRST = "FIRST", SECOND = "SECOND", THIRD = "THIRD" } type TFirst = { type: MyTypes.FIRST foo: string } type TSecond = { type: MyTypes.SECOND foo: string } type TThird = { type: MyTypes.THIRD bar: string } type TConditionalType<T> = T extends MyTypes.FIRST ? TFirst : T extends MyTypes.SECOND ? TSecond : T extends MyTypes.THIRD ? TThird : null const

问题 I have a TypeScript code snippet in the playground. Please take a look there at TypeScript playground or here: enum MyTypes { FIRST = "FIRST", SECOND = "SECOND", THIRD = "THIRD" } type TFirst = { type: MyTypes.FIRST foo: string } type TSecond = { type: MyTypes.SECOND foo: string } type TThird = { type: MyTypes.THIRD bar: string } type TConditionalType<T> = T extends MyTypes.FIRST ? TFirst : T extends MyTypes.SECOND ? TSecond : T extends MyTypes.THIRD ? TThird : null const

问题 I'm trying to create a macro to help with some boilerplate enum code that I've been repetitively writing. I managed to implement a simple enum (i.e. no arguments) relatively easily using a basic macro_rule . e.g. An excerpt: macro_rules! enum_helper { ($type:ident, { $( $name:ident ), * }) => { enum $type { $( $name, )+ } impl FromSql for $type { fn from_sql<R: Read>(_: &Type, raw: &mut R, _: &SessionInfo) -> Result<&type> { // ... the implementation } // ... plus some other internal traits

问题 I'm trying to create a macro to help with some boilerplate enum code that I've been repetitively writing. I managed to implement a simple enum (i.e. no arguments) relatively easily using a basic macro_rule . e.g. An excerpt: macro_rules! enum_helper { ($type:ident, { $( $name:ident ), * }) => { enum $type { $( $name, )+ } impl FromSql for $type { fn from_sql<R: Read>(_: &Type, raw: &mut R, _: &SessionInfo) -> Result<&type> { // ... the implementation } // ... plus some other internal traits