From owner-svn-src-head@freebsd.org Fri Feb 28 00:37:52 2020 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 691C0254BF1 for ; Fri, 28 Feb 2020 00:37:52 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 48T9cJ0ymFz43mv; Fri, 28 Feb 2020 00:37:52 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from John-Baldwins-MacBook-Pro-7.local (ralph.baldwin.cx [66.234.199.215]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: jhb) by smtp.freebsd.org (Postfix) with ESMTPSA id 8074C1B0BB; Fri, 28 Feb 2020 00:37:51 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Subject: Re: svn commit: r358392 - head/share/man/man9 To: Mark Millard , svn-src-head@freebsd.org Cc: Warner Losh References: <217D39BA-4FDC-490C-8490-533D244E79CE.ref@yahoo.com> <217D39BA-4FDC-490C-8490-533D244E79CE@yahoo.com> From: John Baldwin Autocrypt: addr=jhb@FreeBSD.org; keydata= mQGiBETQ+XcRBADMFybiq69u+fJRy/0wzqTNS8jFfWaBTs5/OfcV7wWezVmf9sgwn8TW0Dk0 c9MBl0pz+H01dA2ZSGZ5fXlmFIsee1WEzqeJzpiwd/pejPgSzXB9ijbLHZ2/E0jhGBcVy5Yo /Tw5+U/+laeYKu2xb0XPvM0zMNls1ah5OnP9a6Ql6wCgupaoMySb7DXm2LHD1Z9jTsHcAQMD /1jzh2BoHriy/Q2s4KzzjVp/mQO5DSm2z14BvbQRcXU48oAosHA1u3Wrov6LfPY+0U1tG47X 1BGfnQH+rNAaH0livoSBQ0IPI/8WfIW7ub4qV6HYwWKVqkDkqwcpmGNDbz3gfaDht6nsie5Z pcuCcul4M9CW7Md6zzyvktjnbz61BADGDCopfZC4of0Z3Ka0u8Wik6UJOuqShBt1WcFS8ya1 oB4rc4tXfSHyMF63aPUBMxHR5DXeH+EO2edoSwViDMqWk1jTnYza51rbGY+pebLQOVOxAY7k do5Ordl3wklBPMVEPWoZ61SdbcjhHVwaC5zfiskcxj5wwXd2E9qYlBqRg7QeSm9obiBCYWxk d2luIDxqaGJARnJlZUJTRC5vcmc+iGAEExECACAFAkTQ+awCGwMGCwkIBwMCBBUCCAMEFgID AQIeAQIXgAAKCRBy3lIGd+N/BI6RAJ9S97fvbME+3hxzE3JUyUZ6vTewDACdE1stFuSfqMvM jomvZdYxIYyTUpC5Ag0ERND5ghAIAPwsO0B7BL+bz8sLlLoQktGxXwXQfS5cInvL17Dsgnr3 1AKa94j9EnXQyPEj7u0d+LmEe6CGEGDh1OcGFTMVrof2ZzkSy4+FkZwMKJpTiqeaShMh+Goj XlwIMDxyADYvBIg3eN5YdFKaPQpfgSqhT+7El7w+wSZZD8pPQuLAnie5iz9C8iKy4/cMSOrH YUK/tO+Nhw8Jjlw94Ik0T80iEhI2t+XBVjwdfjbq3HrJ0ehqdBwukyeJRYKmbn298KOFQVHO EVbHA4rF/37jzaMadK43FgJ0SAhPPF5l4l89z5oPu0b/+5e2inA3b8J3iGZxywjM+Csq1tqz hltEc7Q+E08AAwUIAL+15XH8bPbjNJdVyg2CMl10JNW2wWg2Q6qdljeaRqeR6zFus7EZTwtX sNzs5bP8y51PSUDJbeiy2RNCNKWFMndM22TZnk3GNG45nQd4OwYK0RZVrikalmJY5Q6m7Z16 4yrZgIXFdKj2t8F+x613/SJW1lIr9/bDp4U9tw0V1g3l2dFtD3p3ZrQ3hpoDtoK70ioIAjjH aIXIAcm3FGZFXy503DOA0KaTWwvOVdYCFLm3zWuSOmrX/GsEc7ovasOWwjPn878qVjbUKWwx Q4QkF4OhUV9zPtf9tDSAZ3x7QSwoKbCoRCZ/xbyTUPyQ1VvNy/mYrBcYlzHodsaqUDjHuW+I SQQYEQIACQUCRND5ggIbDAAKCRBy3lIGd+N/BCO8AJ9j1dWVQWxw/YdTbEyrRKOY8YZNwwCf afMAg8QvmOWnHx3wl8WslCaXaE8= Message-ID: <59374055-922a-81f1-1b05-a572e1cb6b1a@FreeBSD.org> Date: Thu, 27 Feb 2020 16:37:49 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <217D39BA-4FDC-490C-8490-533D244E79CE@yahoo.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Feb 2020 00:37:52 -0000 On 2/27/20 2:45 PM, Mark Millard wrote: > John Baldwin jhb at FreeBSD.org wrote on > Thu Feb 27 16:55:01 UTC 2020: > >> On 2/27/20 7:30 AM, Warner Losh wrote: >>> Author: imp >>> Date: Thu Feb 27 15:30:13 2020 >>> New Revision: 358392 >>> URL: https://svnweb.freebsd.org/changeset/base/358392 >>> >>> Log: >>> _Static_assert is to be preferred to CTASSERT. >>> >>> Document the existing prefernce that _Static_assert be used in preference to the >>> old CTASSERT we used to use for compile time assertions. >> >> Actually, I think what we want to use is static_assert(). The intention in >> userland C is that _Static_assert() is an internal keyword and >> adds static_assert() as an alias, similar to defining alignas, >> etc. I think what we should do for the kernel is have define >> map static_assert to _Static_assert and replace existing _Static_assert >> usage with the proper spelling. >> > > Be warned static_assert is a C++ keyword as of C++11. > > c++11 added: static_assert(bool_constexpr,message) > c++17 added: static_assert(bool_constexpr) > > C11 added _Static_assert(expression,message) > C2x gets _Static_assert(expression) > > C11 added "#define static_assert _Static_assert" to > > It makes for a bit of a mess in code to be allowed > to be processed by both C and C++. > > The wording may need to specify enough to tell what to > do for such code and the headers may need logic to > cause that context to exist across both languages > when the header is allowed for both. The intent of the C11 changes is to permit equivalent use of static_assert() in both languages. The #define in is guarded to not kick in for C++. -- John Baldwin