## Why is this an issue?

When you annotate an Enum with the Flags attribute, you must not rely on the values that are automatically set by the language to the `Enum` members, but you should define the enumeration constants in powers of two (1, 2, 4, 8, and so on). Automatic value initialization will set the first member to zero and increment the value by one for each subsequent member. As a result, you won’t be able to use the enum members with bitwise operators.

### Exceptions

The default initialization of `0, 1, 2, 3, 4, …​` matches `0, 1, 2, 4, 8 …​` in the first three values, so no issue is reported if the first three members of the enumeration are not initialized.

## How to fix it

Define enumeration constants in powers of two, that is, 1, 2, 4, 8, and so on.

### Code examples

#### Noncompliant code example

    <Flags()>
    Enum FruitType    ' Non-Compliant
      None
      Banana
      Orange
      Strawberry
    End Enum

    Module Module1
      Sub Main()
        Dim bananaAndStrawberry = FruitType.Banana Or FruitType.Strawberry
        Console.WriteLine(bananaAndStrawberry.ToString()) ' Will display only "Strawberry"
      End Sub
    End Module

#### Compliant solution

    <Flags()>
    Enum FruitType    ' Compliant
      None = 0
      Banana = 1
      Orange = 2
      Strawberry = 4
    End Enum

    Module Module1
      Sub Main()
        Dim bananaAndStrawberry = FruitType.Banana Or FruitType.Strawberry
        Console.WriteLine(bananaAndStrawberry.ToString()) ' Will display "Banana, Strawberry"
      End Sub
    End Module

## Resources

### Documentation

- Enum Class
- FlagsAttribute Class