Examples of errors detected by the V3180 diagnostic

V3180. The 'HasFlag' method always returns 'true' because the value '0' is passed as its argument.

RavenDB

V3180 The 'HasFlag' method always returns 'true' because the value of 'TypeAttributes.NotPublic' is '0', and it is passed as the method's argument. ExpressionStringBuilder.cs 2117

[Flags]
public enum TypeAttributes
{
  ....
  NotPublic = 0,
  ....
}

private static bool CheckIfAnonymousType(Type type)
{
  // hack: the only way to detect anonymous types right now
  return type.IsDefined(typeof(CompilerGeneratedAttribute), false)
      && type.IsGenericType && type.Name.Contains("AnonymousType")
      && (type.Name.StartsWith("<>") || type.Name.StartsWith("VB$"))
      && type.Attributes.HasFlag(TypeAttributes.NotPublic);        // <=
}