[{"id":2947,"web_url":"https://patchwork.libcamera.org/comment/2947/","msgid":"","date":"2019-10-23T13:58:38","subject":"Re: [libcamera-devel] [PATCH 1/4] Documentation: coding-style:\n\tDocument usage of C compatibility headers","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Hi Laurent,\n\nOn 23/10/2019 14:52, Laurent Pinchart wrote:\n> The C++ standard defines a set of C++ standard library headers, and for\n> some of them, defines C compatibility headers. The former have a name of\n> the form while the later are named . The C++ headers\n> declare names in the std namespace, and may declare the same names in\n> the global namespace. The C compatibility headers declare names in the\n> global namespace, and may declare the same names in the std namespace.\n> \n> We want to standardise on one set of headers through libcamera, and\n> don't want to rely on optional behaviour. We can thus either use the C++\n> headers with an explicit std:: namespace qualifier through the code, or\n> the C headers without the qualifier.\n> \n> Both set of headers are defined by the C++ standard, and are thus valid\n> choices. After weighting pros and cons, we have decided to use the C\n\ns/weighting/weighing/ :-D\n\n> compatibility headers, as nobody wanted to write std::uint32_t. Document\n> this decision.\n\nSounds good to me.\n\n> \n> Signed-off-by: Laurent Pinchart \n\nReviewed-by: Kieran Bingham \n\n> ---\n> Documentation/coding-style.rst | 12 ++++++++++++\n> 1 file changed, 12 insertions(+)\n> \n> diff --git a/Documentation/coding-style.rst b/Documentation/coding-style.rst\n> index 8dd1afce1a2c..ced3155169a6 100644\n> --- a/Documentation/coding-style.rst\n> +++ b/Documentation/coding-style.rst\n> @@ -170,6 +170,18 @@ These rules match the `object ownership rules from the Chromium C++ Style Guide`\n> long term borrowing isn't marked through language constructs, it shall be\n> documented explicitly in details in the API.\n> \n> +C Compatibility Headers\n> +~~~~~~~~~~~~~~~~~~~~~~~\n> +\n> +The C++ standard defines a set of C++ standard library headers, and for some of\n> +them, defines C compatibility headers. The former have a name of the form\n> + while the later are named . The C++ headers declare names in the\n> +std namespace, and may declare the same names in the global namespace. The C\n> +compatibility headers declare names in the global namespace, and may declare\n> +the same names in the std namespace. Usage of the C compatibility headers is\n> +strongly preferred. Code shall not rely on the optional declaration of names in\n> +the global or std namespace.\n> +\n\nIs this an intentional double blank line ?\n\n> \n> Documentation\n> -------------\n>","headers":{"Return-Path":"","Received":["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 A31666138B\n\tfor ;\n\tWed, 23 Oct 2019 15:58:42 +0200 (CEST)","from [192.168.0.20]\n\t(cpc89242-aztw30-2-0-cust488.18-1.cable.virginm.net [86.31.129.233])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id E533771F;\n\tWed, 23 Oct 2019 15:58:41 +0200 (CEST)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1571839122;\n\tbh=r1aCN0D8aevs9fJELzVq/QG3Mn/REexo9iJHLBqI+XQ=;\n\th=Reply-To:Subject:To:References:From:Date:In-Reply-To:From;\n\tb=hgoghuG3+V5H6iaUIB+FadHA0GDQq5MD+HPUqKZBktHgc3Ioh7hAXfQQioWkvXD6L\n\ti1N8hlxRERJrLW9nC+PucYm+XHchhVPANFlT1Hte1mEZhCinsX4cvXVPhduGXUSyRn\n\tseANePt9sj+hgk3Rix6R6C+fxmhKGaBVWyXJv3Wg=","Reply-To":"kieran.bingham@ideasonboard.com","To":"Laurent Pinchart ,\n\tlibcamera-devel@lists.libcamera.org","References":"<20191023135258.32256-1-laurent.pinchart@ideasonboard.com>","From":"Kieran Bingham ","Openpgp":"preference=signencrypt","Autocrypt":"addr=kieran.bingham@ideasonboard.com; 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Linux x86_64; rv:60.0) Gecko/20100101\n\tThunderbird/60.8.0","MIME-Version":"1.0","In-Reply-To":"<20191023135258.32256-1-laurent.pinchart@ideasonboard.com>","Content-Type":"text/plain; charset=utf-8","Content-Language":"en-GB","Content-Transfer-Encoding":"7bit","Subject":"Re: [libcamera-devel] [PATCH 1/4] Documentation: coding-style:\n\tDocument usage of C compatibility headers","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","X-List-Received-Date":"Wed, 23 Oct 2019 13:58:42 -0000"}},{"id":2949,"web_url":"https://patchwork.libcamera.org/comment/2949/","msgid":"<20191023140441.GB7975@bigcity.dyn.berto.se>","date":"2019-10-23T14:04:41","subject":"Re: [libcamera-devel] [PATCH 1/4] Documentation: coding-style:\n\tDocument usage of C compatibility headers","submitter":{"id":5,"url":"https://patchwork.libcamera.org/api/people/5/","name":"Niklas Söderlund","email":"niklas.soderlund@ragnatech.se"},"content":"Hi Laurent,\n\nThanks for your work.\n\nFor all of the patches in this series,\n\nReviewed-by: Niklas Söderlund \n\nOn 2019-10-23 16:52:55 +0300, Laurent Pinchart wrote:\n> The C++ standard defines a set of C++ standard library headers, and for\n> some of them, defines C compatibility headers. The former have a name of\n> the form while the later are named . The C++ headers\n> declare names in the std namespace, and may declare the same names in\n> the global namespace. The C compatibility headers declare names in the\n> global namespace, and may declare the same names in the std namespace.\n> \n> We want to standardise on one set of headers through libcamera, and\n> don't want to rely on optional behaviour. We can thus either use the C++\n> headers with an explicit std:: namespace qualifier through the code, or\n> the C headers without the qualifier.\n> \n> Both set of headers are defined by the C++ standard, and are thus valid\n> choices. After weighting pros and cons, we have decided to use the C\n> compatibility headers, as nobody wanted to write std::uint32_t. Document\n> this decision.\n> \n> Signed-off-by: Laurent Pinchart \n> ---\n> Documentation/coding-style.rst | 12 ++++++++++++\n> 1 file changed, 12 insertions(+)\n> \n> diff --git a/Documentation/coding-style.rst b/Documentation/coding-style.rst\n> index 8dd1afce1a2c..ced3155169a6 100644\n> --- a/Documentation/coding-style.rst\n> +++ b/Documentation/coding-style.rst\n> @@ -170,6 +170,18 @@ These rules match the `object ownership rules from the Chromium C++ Style Guide`\n> long term borrowing isn't marked through language constructs, it shall be\n> documented explicitly in details in the API.\n> \n> +C Compatibility Headers\n> +~~~~~~~~~~~~~~~~~~~~~~~\n> +\n> +The C++ standard defines a set of C++ standard library headers, and for some of\n> +them, defines C compatibility headers. The former have a name of the form\n> + while the later are named . The C++ headers declare names in the\n> +std namespace, and may declare the same names in the global namespace. The C\n> +compatibility headers declare names in the global namespace, and may declare\n> +the same names in the std namespace. Usage of the C compatibility headers is\n> +strongly preferred. Code shall not rely on the optional declaration of names in\n> +the global or std namespace.\n> +\n> \n> Documentation\n> -------------\n> -- \n> Regards,\n> \n> Laurent Pinchart\n> \n> _______________________________________________\n> libcamera-devel mailing list\n> libcamera-devel@lists.libcamera.org\n> https://lists.libcamera.org/listinfo/libcamera-devel","headers":{"Return-Path":"","Received":["from mail-lj1-x243.google.com (mail-lj1-x243.google.com\n\t[IPv6:2a00:1450:4864:20::243])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 205756138B\n\tfor ;\n\tWed, 23 Oct 2019 16:04:43 +0200 (CEST)","by mail-lj1-x243.google.com with SMTP id u4so7128362ljj.9\n\tfor ;\n\tWed, 23 Oct 2019 07:04:43 -0700 (PDT)","from localhost (h-93-159.A463.priv.bahnhof.se. 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