{"action":"created","issue":{"url":"https://api.github.com/repos/dotnet/corefx/issues/373","labels_url":"https://api.github.com/repos/dotnet/corefx/issues/373/labels{/name}","comments_url":"https://api.github.com/repos/dotnet/corefx/issues/373/comments","events_url":"https://api.github.com/repos/dotnet/corefx/issues/373/events","html_url":"https://github.com/dotnet/corefx/issues/373","id":53722374,"number":373,"title":"BitVector32 should implement IEquatable<T>","user":{"login":"justinvp","id":710598,"avatar_url":"https://avatars.githubusercontent.com/u/710598?v=3","gravatar_id":"","url":"https://api.github.com/users/justinvp","html_url":"https://github.com/justinvp","followers_url":"https://api.github.com/users/justinvp/followers","following_url":"https://api.github.com/users/justinvp/following{/other_user}","gists_url":"https://api.github.com/users/justinvp/gists{/gist_id}","starred_url":"https://api.github.com/users/justinvp/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/justinvp/subscriptions","organizations_url":"https://api.github.com/users/justinvp/orgs","repos_url":"https://api.github.com/users/justinvp/repos","events_url":"https://api.github.com/users/justinvp/events{/privacy}","received_events_url":"https://api.github.com/users/justinvp/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/dotnet/corefx/labels/api%20addition","name":"api addition","color":"207de5"}],"state":"closed","locked":false,"assignee":{"login":"FiveTimesTheFun","id":6598317,"avatar_url":"https://avatars.githubusercontent.com/u/6598317?v=3","gravatar_id":"","url":"https://api.github.com/users/FiveTimesTheFun","html_url":"https://github.com/FiveTimesTheFun","followers_url":"https://api.github.com/users/FiveTimesTheFun/followers","following_url":"https://api.github.com/users/FiveTimesTheFun/following{/other_user}","gists_url":"https://api.github.com/users/FiveTimesTheFun/gists{/gist_id}","starred_url":"https://api.github.com/users/FiveTimesTheFun/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/FiveTimesTheFun/subscriptions","organizations_url":"https://api.github.com/users/FiveTimesTheFun/orgs","repos_url":"https://api.github.com/users/FiveTimesTheFun/repos","events_url":"https://api.github.com/users/FiveTimesTheFun/events{/privacy}","received_events_url":"https://api.github.com/users/FiveTimesTheFun/received_events","type":"User","site_admin":false},"milestone":null,"comments":6,"created_at":"2015-01-08T07:28:52Z","updated_at":"2015-09-17T19:00:54Z","closed_at":"2015-09-17T19:00:54Z","body":"`BitVector32` and `BitVector32.Section` are both structs that override `Equals` and `GetHashCode`. `BitVector32.Section` even has an `Equals(Section)` overload. Should these value types implement `IEquatable<T>` per the design guidelines?\r\n\r\n`BitVector32` is in `System.Collections.Specialized`. I understand that most of the collections in `System.Collections.Specialized` are considered *legacy*, are here mainly for backwards compatibility, and therefore shouldn't be invested in per @davkean's [comments](https://github.com/dotnet/corefx/issues/370#issuecomment-69140116). However, I'm not sure I'd necessarily consider `BitVector32` *legacy* as it does appear to be useful on its own and isn't replaced by anything else (that I'm aware of).\r\n\r\n## Proposed API\r\n\r\n```c#\r\n// Previously didn't implement IEquatable<T>\r\npublic struct BitVector32 : IEquatable<BitVector32>\r\n{\r\n    // Existing members\r\n    public override bool Equals(object o);\r\n    public override int GetHashCode();\r\n\r\n    // Proposed members\r\n    public bool Equals(BitVector32 other);\r\n    public static bool operator ==(BitVector32 left, BitVector32 right);\r\n    public static bool operator !=(BitVector32 left, BitVector32 right);\r\n\r\n    ...\r\n\r\n    // Previously didn't implement IEquatable<T>\r\n    public struct Section : IEquatable<Section>\r\n    {\r\n        // Existing members\r\n        public override bool Equals(object o);\r\n        public bool Equals(Section obj);\r\n        public static bool operator ==(Section a, Section b);\r\n        public static bool operator !=(Section a, Section b);\r\n        public override int GetHashCode();\r\n\r\n        // No new members required\r\n\r\n        ...\r\n    }\r\n}\r\n```"},"comment":{"url":"https://api.github.com/repos/dotnet/corefx/issues/comments/141190065","html_url":"https://github.com/dotnet/corefx/issues/373#issuecomment-141190065","issue_url":"https://api.github.com/repos/dotnet/corefx/issues/373","id":141190065,"user":{"login":"terrajobst","id":5169960,"avatar_url":"https://avatars.githubusercontent.com/u/5169960?v=3","gravatar_id":"","url":"https://api.github.com/users/terrajobst","html_url":"https://github.com/terrajobst","followers_url":"https://api.github.com/users/terrajobst/followers","following_url":"https://api.github.com/users/terrajobst/following{/other_user}","gists_url":"https://api.github.com/users/terrajobst/gists{/gist_id}","starred_url":"https://api.github.com/users/terrajobst/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/terrajobst/subscriptions","organizations_url":"https://api.github.com/users/terrajobst/orgs","repos_url":"https://api.github.com/users/terrajobst/repos","events_url":"https://api.github.com/users/terrajobst/events{/privacy}","received_events_url":"https://api.github.com/users/terrajobst/received_events","type":"User","site_admin":false},"created_at":"2015-09-17T19:00:54Z","updated_at":"2015-09-17T19:00:54Z","body":"We've made the decision to treat `BitVector32` the same way we treat non-generic collection, which is that they are legacy types provided to support existing code. However, we don't want to invest in them and add new functionality."}}