{"id":11128,"url":"https://patchwork.libcamera.org/api/1.1/patches/11128/?format=json","web_url":"https://patchwork.libcamera.org/patch/11128/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20210204035951.23751-1-laurent.pinchart@ideasonboard.com>","date":"2021-02-04T03:59:50","name":"[libcamera-devel,1/2] libcamera: Add macro to conditionally use [[nodiscard]]","commit_ref":"6dfa2040820d44584a1c5430f42dfc9b1ea56c9a","pull_url":null,"state":"accepted","archived":false,"hash":"d4ff114d0b249823b0c3f6fb6ece68bf452d9be3","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/1.1/people/2/?format=json","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/11128/mbox/","series":[{"id":1648,"url":"https://patchwork.libcamera.org/api/1.1/series/1648/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=1648","date":"2021-02-04T03:59:50","name":"[libcamera-devel,1/2] libcamera: Add macro to conditionally use [[nodiscard]]","version":1,"mbox":"https://patchwork.libcamera.org/series/1648/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/11128/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/11128/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 2C054BD160\n\tfor ;\n\tThu, 4 Feb 2021 04:00:19 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 9D866613F8;\n\tThu, 4 Feb 2021 05:00:18 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 23A5E613DA\n\tfor ;\n\tThu, 4 Feb 2021 05:00:17 +0100 (CET)","from pendragon.lan (62-78-145-57.bb.dnainternet.fi [62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 9B1155A5\n\tfor ;\n\tThu, 4 Feb 2021 05:00:16 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"nRHx/Xuv\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1612411216;\n\tbh=JKkU5tDdpjA+IoDcO3tP0tc2j9O4b4X99oYhJ30Vyf4=;\n\th=From:To:Subject:Date:From;\n\tb=nRHx/XuvRiGWAMNon9oTbbkZq3BsVF50H9iw0NAZhwO6Lam+/UFtoLbTJ3EpAkh2C\n\tPwLgshv+wCVkZSRDJCfANyMw9kRlKj3W07lZurP0UeQlIDZejMjqc38muzaM4e9Py+\n\tfnfkcezZC5DrjbQZssroDIO3g3b0ITVa+9UrvkR8=","From":"Laurent Pinchart ","To":"libcamera-devel@lists.libcamera.org","Date":"Thu, 4 Feb 2021 05:59:50 +0200","Message-Id":"<20210204035951.23751-1-laurent.pinchart@ideasonboard.com>","X-Mailer":"git-send-email 2.28.0","MIME-Version":"1.0","Subject":"[libcamera-devel] [PATCH 1/2] libcamera: Add macro to conditionally\n\tuse [[nodiscard]]","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"The [[nodiscard]] attribute has been added to C++17. It can thus be used\ninside libcamera, but would prevent applications compiled for C++14 to\nuse libcamera if the attribute was used in public headers.\n\nTo offer this feature when the application is compiled with a\nrecent-enough C++ version, as well as for compiling libcamera itself,\nadd a __nodiscard macro that expands as [[nodiscard]] when using C++17\nor newer.\n\nSigned-off-by: Laurent Pinchart \n---\n include/libcamera/compiler.h | 16 ++++++++++++++++\n include/libcamera/meson.build | 1 +\n 2 files changed, 17 insertions(+)\n create mode 100644 include/libcamera/compiler.h","diff":"diff --git a/include/libcamera/compiler.h b/include/libcamera/compiler.h\nnew file mode 100644\nindex 000000000000..dc56dbb8b792\n--- /dev/null\n+++ b/include/libcamera/compiler.h\n@@ -0,0 +1,16 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2021, Google Inc.\n+ *\n+ * compiler.h - Compiler support\n+ */\n+#ifndef __LIBCAMERA_COMPILER_H__\n+#define __LIBCAMERA_COMPILER_H__\n+\n+#if __cplusplus >= 201703L\n+#define __nodiscard\t\t[[nodiscard]]\n+#else\n+#define __nodiscard\n+#endif\n+\n+#endif /* __LIBCAMERA_COMPILER_H__ */\ndiff --git a/include/libcamera/meson.build b/include/libcamera/meson.build\nindex cf2935f1ee95..13e9eeb6d6ad 100644\n--- a/include/libcamera/meson.build\n+++ b/include/libcamera/meson.build\n@@ -5,6 +5,7 @@ libcamera_public_headers = files([\n 'buffer.h',\n 'camera.h',\n 'camera_manager.h',\n+ 'compiler.h',\n 'controls.h',\n 'extensible.h',\n 'file_descriptor.h',\n","prefixes":["libcamera-devel","1/2"]}