{"action":"opened","issue":{"url":"https://api.github.com/repos/conan-io/conan/issues/126","labels_url":"https://api.github.com/repos/conan-io/conan/issues/126/labels{/name}","comments_url":"https://api.github.com/repos/conan-io/conan/issues/126/comments","events_url":"https://api.github.com/repos/conan-io/conan/issues/126/events","html_url":"https://github.com/conan-io/conan/issues/126","id":130147304,"number":126,"title":"mark headers as \"SYSTEM\" headers to silence warnings","user":{"login":"TyRoXx","id":941829,"avatar_url":"https://avatars.githubusercontent.com/u/941829?v=3","gravatar_id":"","url":"https://api.github.com/users/TyRoXx","html_url":"https://github.com/TyRoXx","followers_url":"https://api.github.com/users/TyRoXx/followers","following_url":"https://api.github.com/users/TyRoXx/following{/other_user}","gists_url":"https://api.github.com/users/TyRoXx/gists{/gist_id}","starred_url":"https://api.github.com/users/TyRoXx/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/TyRoXx/subscriptions","organizations_url":"https://api.github.com/users/TyRoXx/orgs","repos_url":"https://api.github.com/users/TyRoXx/repos","events_url":"https://api.github.com/users/TyRoXx/events{/privacy}","received_events_url":"https://api.github.com/users/TyRoXx/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-01-31T16:26:18Z","updated_at":"2016-01-31T16:26:18Z","closed_at":null,"body":"Many libraries generate tons of warnings in public headers. WebSocket++ uses auto_ptr for example and many Boost libraries truncate integers implicitly (-Wconversion). To consume these libraries you have to treat them as system headers because GCC won't emit warnings in these.\r\n\r\nThis is how Conan currently sets the include directories:\r\n```CMake\r\ninclude_directories(${CONAN_INCLUDE_DIRS})\r\n```\r\n\r\nThis is how you would add them as \"system\" headers to silence warnings:\r\n```CMake\r\ninclude_directories(SYSTEM ${CONAN_INCLUDE_DIRS})\r\n```\r\n\r\nIs there a reason it is not already done this way?\r\nThis issue may apply to configurations other than CMake/GCC, too, but this is the most important one for me."}}