Question

In .Net I can (and should) apply the FlagsAttribute to enums that are used as bitmask. This way I can use the HasFlag()-method and ReSharper doesn’t get angry if I do bitwise operations on them.

In a project I have to use an enum from a dll written in vb6 which of course does not have the FlagsAttribute. (I have seen the code, the values are bit flags.)

Eventhough VisualStudio marks it as red in code whenever I use .HasFlag(), it compiles and runs just fine. And I can “disable” the ReSharper warning on bitwise operations by always casting the enum to int (or suppress it with a comment, …)

Yet I wonder if there is a somewhat cleaner approach like marking the enum as flags once?

Answer 1

You can’t mark an external dependency – if you have a dll, whatever its source, you can’t simply change its internals (well, you can, but that would require rewriting the binary).

One option is to write your own flags enumeration and a mapper between the VB6 one and yours and simply use your version in your code and simply ignore the issues in the mapping layer.