{"action":"created","issue":{"url":"https://api.github.com/repos/JuliaLang/julia/issues/6838","repository_url":"https://api.github.com/repos/JuliaLang/julia","labels_url":"https://api.github.com/repos/JuliaLang/julia/issues/6838/labels{/name}","comments_url":"https://api.github.com/repos/JuliaLang/julia/issues/6838/comments","events_url":"https://api.github.com/repos/JuliaLang/julia/issues/6838/events","html_url":"https://github.com/JuliaLang/julia/issues/6838","id":33480159,"number":6838,"title":"Triangular: no implementation of `similar`, `setindex!`","user":{"login":"timholy","id":1525481,"avatar_url":"https://avatars.githubusercontent.com/u/1525481?v=3","gravatar_id":"","url":"https://api.github.com/users/timholy","html_url":"https://github.com/timholy","followers_url":"https://api.github.com/users/timholy/followers","following_url":"https://api.github.com/users/timholy/following{/other_user}","gists_url":"https://api.github.com/users/timholy/gists{/gist_id}","starred_url":"https://api.github.com/users/timholy/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/timholy/subscriptions","organizations_url":"https://api.github.com/users/timholy/orgs","repos_url":"https://api.github.com/users/timholy/repos","events_url":"https://api.github.com/users/timholy/events{/privacy}","received_events_url":"https://api.github.com/users/timholy/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/JuliaLang/julia/labels/linear%20algebra","name":"linear algebra","color":"aa8800"}],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":17,"created_at":"2014-05-14T10:33:48Z","updated_at":"2016-02-12T22:21:39Z","closed_at":"2015-01-16T21:35:07Z","body":"I had code that looked like this:\r\n```\r\nL = chol(A, :L)\r\nX = similar(L)\r\n```\r\nThis broke when `chol` started returning a `Triangular` type. I started to implement `similar` for `Triangular` (creating another `Triangular` type), but then noticed there is no `setindex!`. Since the next thing my code did was stuff some values in `X`, that would fail.\r\n\r\nSo before doing anything, I should ask: is the omission of `setindex!` deliberate?\r\n"},"comment":{"url":"https://api.github.com/repos/JuliaLang/julia/issues/comments/183510017","html_url":"https://github.com/JuliaLang/julia/issues/6838#issuecomment-183510017","issue_url":"https://api.github.com/repos/JuliaLang/julia/issues/6838","id":183510017,"user":{"login":"bisraelsen","id":3248556,"avatar_url":"https://avatars.githubusercontent.com/u/3248556?v=3","gravatar_id":"","url":"https://api.github.com/users/bisraelsen","html_url":"https://github.com/bisraelsen","followers_url":"https://api.github.com/users/bisraelsen/followers","following_url":"https://api.github.com/users/bisraelsen/following{/other_user}","gists_url":"https://api.github.com/users/bisraelsen/gists{/gist_id}","starred_url":"https://api.github.com/users/bisraelsen/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/bisraelsen/subscriptions","organizations_url":"https://api.github.com/users/bisraelsen/orgs","repos_url":"https://api.github.com/users/bisraelsen/repos","events_url":"https://api.github.com/users/bisraelsen/events{/privacy}","received_events_url":"https://api.github.com/users/bisraelsen/received_events","type":"User","site_admin":false},"created_at":"2016-02-12T22:21:39Z","updated_at":"2016-02-12T22:21:39Z","body":"I only meant to use the `XTriangular` solution as a guide for me to add `setindex!` support for `Symmetric`, as I am new to the project. However, `setindex!` definitely should not have the same implementation.\r\n\r\nI had planned only on allowing changes that maintain symmetry. For example if someone changes index `(i,j)` then `(j,i)` would also be changed..."}}