Issue 3483 - Eliminate read-modify-write operations for enums

[yebblies]

Disable rmw operations for enums (+=, -=, *=, ++, --, etc)

http://d.puremagic.com/issues/show_bug.cgi?id=3483

The corresponding phobos pull request is: (already merged)
dlang/phobos#127

[braddr]

I don't know that I like eliminating the bitwise operators. Enums are so often used as named bitflags. As perfect example, part of what you had to fix in phobos. The rest, I can see eliminating.

[yebblies]

I'm not 100% on this either. It can be useful, but it also easily creates a value that is not a member of the enum, and that is arguably wrong. This is part of the reason behind previous proposals of a separate bitflags enum type.
It might be worth voicing your concerns on the bugzilla page as well.

[WalterBright]

I'm going to reject this one. I'm not convinced it is a significant source of bugs, there are many legitimate uses of op= for enums, and the rather loose definition of them is traditional for C.