{"action":"created","issue":{"url":"https://api.github.com/repos/ericniebler/stl2/issues/19","labels_url":"https://api.github.com/repos/ericniebler/stl2/issues/19/labels{/name}","comments_url":"https://api.github.com/repos/ericniebler/stl2/issues/19/comments","events_url":"https://api.github.com/repos/ericniebler/stl2/issues/19/events","html_url":"https://github.com/ericniebler/stl2/issues/19","id":73717331,"number":19,"title":"Do we need concept StrictWeakOrdering ?","user":{"login":"ericniebler","id":225757,"avatar_url":"https://avatars.githubusercontent.com/u/225757?v=3","gravatar_id":"","url":"https://api.github.com/users/ericniebler","html_url":"https://github.com/ericniebler","followers_url":"https://api.github.com/users/ericniebler/followers","following_url":"https://api.github.com/users/ericniebler/following{/other_user}","gists_url":"https://api.github.com/users/ericniebler/gists{/gist_id}","starred_url":"https://api.github.com/users/ericniebler/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ericniebler/subscriptions","organizations_url":"https://api.github.com/users/ericniebler/orgs","repos_url":"https://api.github.com/users/ericniebler/repos","events_url":"https://api.github.com/users/ericniebler/events{/privacy}","received_events_url":"https://api.github.com/users/ericniebler/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":7,"created_at":"2015-05-06T19:43:05Z","updated_at":"2015-05-24T04:58:25Z","closed_at":"2015-05-24T02:10:13Z","body":""},"comment":{"url":"https://api.github.com/repos/ericniebler/stl2/issues/comments/104979469","html_url":"https://github.com/ericniebler/stl2/issues/19#issuecomment-104979469","issue_url":"https://api.github.com/repos/ericniebler/stl2/issues/19","id":104979469,"user":{"login":"sean-parent","id":2279724,"avatar_url":"https://avatars.githubusercontent.com/u/2279724?v=3","gravatar_id":"","url":"https://api.github.com/users/sean-parent","html_url":"https://github.com/sean-parent","followers_url":"https://api.github.com/users/sean-parent/followers","following_url":"https://api.github.com/users/sean-parent/following{/other_user}","gists_url":"https://api.github.com/users/sean-parent/gists{/gist_id}","starred_url":"https://api.github.com/users/sean-parent/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/sean-parent/subscriptions","organizations_url":"https://api.github.com/users/sean-parent/orgs","repos_url":"https://api.github.com/users/sean-parent/repos","events_url":"https://api.github.com/users/sean-parent/events{/privacy}","received_events_url":"https://api.github.com/users/sean-parent/received_events","type":"User","site_admin":false},"created_at":"2015-05-24T04:58:25Z","updated_at":"2015-05-24T04:58:25Z","body":"The comp for these algorithms is a bit odd in that we allow asymmetric\ncomparisons since we don't have projections. The requirement is that the\ncomparison portion be strict-weak (otherwise I don't know what these\nalgorithms mean) and that the range be sorted by the same comparison. Don't\nknow how the current wording ended up in the standard - maybe it was a\n\"punt\" to allow the asymmetric compare?\n\nOn Sat, May 23, 2015 at 2:46 PM, Eric Niebler <notifications@github.com>\nwrote:\n\n> Section [alg.sorting] in the standard has this to say about all the\n> sorting algorithms:\n>\n> For algorithms other than those described in 25.4.3 to work correctly,\n> comp has to induce a strict weak ordering on the values.\n>\n> 25.4.3 are the binary search algorithms: lower_bound, upper_bound,\n> equal_range, and binary_search. The above seems to suggest these\n> algorithms do not require a strict weak ordering relation, but the Palo\n> Alto report disagrees. It reads:\n>\n> The binary search algorithms define a family of related operations on\n> sorted data. All of these\n> algorithms in this section have an implied precondition that their input\n> ranges [first, last) are\n> sorted either by the total ordering of their value types or with respect\n> to the given (strict) weak\n> ordering.\n>\n> I'm going with the Palo Alto constraints, but I'd like to understand why\n> the current standard says what it does. Thoughts, anyone? @asutton\n> <https://github.com/asutton>? @sean-parent\n> <https://github.com/sean-parent>?\n>\n> —\n> Reply to this email directly or view it on GitHub\n> <https://github.com/ericniebler/stl2/issues/19#issuecomment-104947236>.\n>\n"}}