From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Arne Babenhauserheide Newsgroups: gmane.lisp.guile.devel Subject: Re: Immediate doubles (up to 2^256) and rationals coming to Guile 3 Date: Sat, 08 Jun 2019 11:46:10 +0200 Message-ID: <87a7eswgt9.fsf@web.de> References: <87zhmvaw5p.fsf@netris.org> <877e9wc210.fsf@netris.org> <87blz8wlda.fsf@web.de> <20190608100825.7ae761680debe51e487913f1@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="15693"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: mu4e 1.2.0; emacs 26.1 To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Sat Jun 08 11:46:43 2019 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hZXvu-0003wl-CI for guile-devel@m.gmane.org; Sat, 08 Jun 2019 11:46:42 +0200 Original-Received: from localhost ([::1]:56428 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hZXvs-0007mU-R5 for guile-devel@m.gmane.org; Sat, 08 Jun 2019 05:46:40 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47298) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hZXvn-0007m4-G5 for guile-devel@gnu.org; Sat, 08 Jun 2019 05:46:36 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hZXvl-00010a-WB for guile-devel@gnu.org; Sat, 08 Jun 2019 05:46:35 -0400 Original-Received: from mout.web.de ([212.227.15.3]:44945) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hZXvl-0000rA-Ho for guile-devel@gnu.org; Sat, 08 Jun 2019 05:46:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1559987176; bh=OvBHpYPxRzW1TIQLc116BlmaMIetDuy2VhQApx4mGp4=; h=X-UI-Sender-Class:References:From:To:Subject:In-reply-to:Date; b=SNbEQGumywqdW/o9g5d8V3z8SqBHe40vAnMRSfOYO+LJ7WobxeSBWTf2LVcZSmt3Q vzSLKAT5pjbMGAGsPctclGUOjpE9lqdSqk5KkFReEIxMAyyW9RX+o555VRSBgmDOZK HxGZbpM6OohG9WvG4tkQ6pxwmoqavjwclAwVN0DY= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Original-Received: from fluss ([84.149.88.72]) by smtp.web.de (mrweb003 [213.165.67.108]) with ESMTPSA (Nemesis) id 0Lb289-1goygr286b-00khvL; Sat, 08 Jun 2019 11:46:16 +0200 In-reply-to: <20190608100825.7ae761680debe51e487913f1@gmail.com> X-Provags-ID: V03:K1:13IGrxJ/KwwxnfEcaGWlGG0wNxTNEbOdI4wB5AZDG0Qpnpbgmg1 bYqdWcibEN2vMhmBYiV2YZIHV5hFH/0q5/MYDjOrnEGco9ZDE2/bY0s8pdDoZ7Q+nm/C6+X JWHnYDnEBfELfsX/DBjah+CI1VtKP6J3InAPqftsFdn+xYhgyKG8LhpAbUpCBqT0Nm/83It avrKJAle6zk/p/tLX9rVA== X-UI-Out-Filterresults: notjunk:1;V03:K0:+tiR6H4AI/o=:YVNfZXIbSmcq74JvZiFPz+ UCPnfEQUwlgucLKRyT+GiEvGyKOqTpffbd/fPmNMP9E56ZMGY6OZd/zMBwe0qP+fEvMbA5B7J 5yEO61C46uWU3yPoXd3WtitCLQQlCOsdOrtMCba7NTjbvMbhU9S9RcXgcCWdIFjhrmZVt1LaN 5qdBd+xsHbyu5v2jbDvWBuiPHd2pfAQhD/E3oEOO2/c4iIRfomHVk7rReEhGHeIlgiWQLy8Pt JQjr4vFGaq24puFf0U453v2c9ioTXPzy7oCw8/Ln7xyhPtpFlcmoS6aBTDrfsimcEhuTZvJ+Z 63qi121zdR7EgtoJbxeogbBgdyLUOdFBxZ8BrHG2BBavDUP/oCGk95lPMP4xPIf6rxkipElKt wSXE2S78jLNd4xLUtTWucIdBU032ORL4QUrRv56E0EGNnTbJkNAD7Ij6ye01zGqQgeRICpP0N N+eTI/bDy9/BHkwIlWSSxGYWxXGUP4dSRBhrYeI6xi4ZQp+zP3nS6ymKZO8wpC/+OchSY5KAU cxSUdqYUL+JYKiEBBNEGDZVkIRsnLk+5pEfl6nIDYdQ X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 212.227.15.3 X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Original-Sender: "guile-devel" Xref: news.gmane.org gmane.lisp.guile.devel:19955 Archived-At: --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Chris Vine writes: > On Sat, 08 Jun 2019 10:07:45 +0200 > Arne Babenhauserheide wrote: > [snip] >> Wow, I didn=E2=80=99t know that you could do that. >>=20 >> However: "The details of that allocation are implementation-defined, and >> it's undefined behavior to read from the member of the union that wasn't >> most recently written." https://en.cppreference.com/w/cpp/language/union >>=20 >> Can you guarantee that this works? > > This is C and not C++ and the provision to which you refer does not > apply. > > Reading from a member of a union other than the one last written to is > implementation defined in C89/90, and defined in C99 (with Technical > Corrigendum 3) and above Thank you for the correction and explanation! Best wishes, Arne =2D-=20 Unpolitisch sein hei=C3=9Ft politisch sein ohne es zu merken --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE801qEjXQSQPNItXAE++NRSQDw+sFAlz7g+MACgkQE++NRSQD w+v00BAAvqvfMrra/M9KbbV7YDz0XzGJU0ahFR6xnd4SdW9SPVtjG0XPqNFUG0ex rrpACVox7q21iTd7Zg78ZXagbzqFTz5Cj/yrts0vceNngrBIsXjapM51x7dj4lHf 9Sajgqi/LU45y6vd/913327TO+1irBXtF0DQKPvHcvxt+OOr73aeW0Mk1oEb49Yh gEhU6JAMcrEzGy5P1LCDikzgasDgd3Gh5qbR/jwrEgo+zHVvBzTAM4Z5L6Aobwhm 4OqA4veMblYzAe2GsXI+cMgLhB052YtXmI56FQIuVXf4ZBtmlaYNu4c0PaKE9fHa zhdEj0TZJ5s7qyoWS+DK6f6Pe5EczI2UUNDP0OTOKCeZ2oTEGHSMwkMMdioYRv0P pWpfS0QQvpdpK/Yo8xyTgpETQZ2RgfldhOYp3PyfsSWbm3rGjznwQxgCDD4hR7pt Btg0ysjJ2k3zgu5d2vaEJciEGcLEQM98xnR++ejy5ms8SnhGATgavcEe9Xppr3Vb 7aDUFbfjHWItMnvVxPkv7WKrj0zPro8JUy032GEzH+q5n2rU3K3RK/xhejreMECk uoQpW8QpVPpCOGPDwahrYGDzjfgIxw5ANlbe0GMH81bCw3/Bu7jxGFKYM3WArlvX t3avIWqlF2vWqwNGby9nrOLhTC1qwLRVJ71Pc2jHL8+PGYYPyb+IswQBAQgAHRYh BN0ovebZh1yrzkqLHdzPDbMLwQVIBQJc+4PjAAoJENzPDbMLwQVIuPcD+gJ1W0tH NmVxbDZvqiDy2FA4YRLqzT6OQ99ZJfWqD1XBAQRAJ3538liRqqRuWI+AtT76tssf BP3CvNk5fHbQ+amLxOIQXl9gok1sKVI6hi4F+b5zIaJIVzR3rT6PsZ/wjjog5qM/ rIcOhd039hdYRIZNCAMwAiX40Obi0MXgv0/M =A1B0 -----END PGP SIGNATURE----- --=-=-=--