No equality operators for IUser (and possibly others)

[Foxtrek64]

This makes it impossible to use LINQ and other built-in methods for ensuring that objects are equal to each other. Will submit a pull request with this.

IReadOnlyCollection<IUser> usersReacted = await msg.GetReactionUsersAsync(emote.Name); // Returns list of 25 users (subset of everyone in guild)
IReadOnlyCollection<IUser> usersInGuild = sguser.Guild.Users; // Returns list of 50 users
IEnumerable<IUser> usersToRemove = usersInGuild.Except(usersReacted); // Should return everyone in the guild except those who reacted

usersToRemove ends up being the same as usersInGuild. I'll try and find a less-painful solution than doing things manually.

[khionu]

1. You can use the IDs, instead. That's how I've done my Linq in bots, and I imagine how most people do.
2. This is almost certainly how it would be done internally. If you wanted to PR it, you'd be free to (the acceptance of it to the lib would be up to the maintainers, though)

[Foxtrek64]

I can wrangle the return type for GetReactionUsersAsync to be a RestUser, but the only common type between RestUser and SocketGuildUser (The return type of sguser.Guild.Users) is IUser where equality is broken. Thus, the only kind of thing I can think of doing is writing my own method that steps through both collections and only takes the unique values based on ID, but it would be far easier to just rely on the built-in methods.

[Joe4evr]

Thus, the only kind of thing I can think of doing is writing my own method that steps through both collections and only takes the unique values based on ID

.Except() (and just about every other LINQ method) has an overload that takes in an IEqualityComparer<T> at which point you can just do something like this. No need to write your own methods.

[khionu]

Like I noted, you can always use the IDs

if (restUserObject.Id == socketUserObject.Id)
    return;

[FiniteReality]

Keep in mind that we already tried something like this in #181 and it ended up being postponed almost indefinitely. However, this is a good place to discuss it properly, so cc @RogueException @foxbot

[Foxtrek64]

There seem to be two solutions for this. Here's the code I'm using as suggested by @khionu:

IEnumerable<IUser> usersReacted = await msg.GetReactionUsersAsync(emote.Name);
IEnumerable<IUser> usersToRemove = (channel.Guild.Users).Where(x => usersReacted.All(y => x.Id != y.Id));

And the other option is implementing an IEqualityComparer<T> as suggested by @Joe4evr.

The solution I'm using now definitely works, though I would very much be in favor of seeing a handful of IEqualityComparers added in as a more long-term and maintainable solution.

[Joe4evr]

If we're gonna add comparers to the base library, then I nominate to consider the one I linked, because it works perfectly and I've spent a good amount of time refining it to get lazy-initialization with low overhead.

[foxbot]

@Joe4evr if you want to PR yours, seems good to me - I don't see any reason why we shouldn't have these

[Still34]

I second IEqualityComparer.

[Still34]

Should probably be closed now that comparers have been added.