C# enum(like) with non-integer type casts (by source generator)
It is difficult to handle enums in relation to non-integer types, but there is a classic workaround that makes handling them convenient by pseudo-handling them with structs. EnumWithValues uses a source generator to make this workaround convenient and fast to use.
EnumWithValues can be installed and used from nuget.
Because EnumWithValues uses a source generator, you need to restart Visual Studio once after installation.
Use [EnumWithValues(structName)] and [EnumValue(params string[] values)] attribute like below.
[EnumWithValues("Foo", convertEnumValue: true, throwIfCastFails: false)]
public enum FooEnum {
[EnumValue("OK")]
OK = 200,
[EnumValue("No Content")]
No_Content = 204,
}then source generator builds enum like Foo struct.
Foo.No_Content == 204using EnumWithValues;
namespace MyApp {
[EnumWithValues("StatusCode")]
public enum StatusCodeEnum {
[EnumValue("OK")]
OK = 200,
[EnumValue("No Content")]
No_Content = 204,
}
public class Response_StructBase {
public StatusCode StatusCode { get; set; }
public StatusCodeEnum StatusCodeEnum { get => StatusCode; set => StatusCode = value; }
}
public class Response_EnumBase {
public StatusCode StatusCode { get => StatusCodeEnum; set => StatusCodeEnum = value; }
public StatusCodeEnum StatusCodeEnum { get; set; }
}
[TestClass]
public class MyAppTest {
[TestMethod]
public void StructBase() {
var res = new Response_StructBase { StatusCode = 200 };
Assert.IsTrue(res.StatusCode == res.StatusCodeEnum);
Assert.IsTrue(res.StatusCode == "OK");
Assert.IsTrue(res.StatusCode == 200);
Assert.IsTrue(res.StatusCode == StatusCode.OK);
Assert.IsTrue(res.StatusCode == StatusCodeEnum.OK);
}
[TestMethod]
public void EnumBase() {
var res = new Response_EnumBase { StatusCode = 200 };
Assert.IsTrue(res.StatusCode == res.StatusCodeEnum);
Assert.IsTrue(res.StatusCode == "OK");
Assert.IsTrue(res.StatusCode == 200);
Assert.IsTrue(res.StatusCode == StatusCode.OK);
Assert.IsTrue(res.StatusCode == StatusCodeEnum.OK);
}
}
}[EnumWithValues("Foo", convertEnumValue: false)] // do `convertEnumValue = false` when you use [EnumValue(int)]
public enum FooEnum {
[EnumValue("A", 'a', 1)] // Foo. "A" && Foo. 'A' && Foo. 1
One,
[EnumValue("B", 'b', 2)] // MUST: same types order
Two,
}Foo is an instance, while switch case only accepts const. Therefore, this workaround is necessary.
var myEnum = MyEnum.Foo;
switch (myEnum.AsEnum) {
case MyEnum.Enum.Foo:
return true;
}These limitations are caused by the fact that I don't know much about code scanning in Roslyn.
Pull Request welcome !!!
ulong enum value > long not supported.