Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1gDEmb-0001fb-Gh for pgsql-hackers@arkaria.postgresql.org; Thu, 18 Oct 2018 20:20:37 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1gDEmZ-00036q-Cb for pgsql-hackers@arkaria.postgresql.org; Thu, 18 Oct 2018 20:20:35 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1gDEmZ-00036Q-27 for pgsql-hackers@lists.postgresql.org; Thu, 18 Oct 2018 20:20:35 +0000 Received: from out3-smtp.messagingengine.com ([66.111.4.27]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1gDEmW-0001dN-Cm for pgsql-hackers@postgresql.org; Thu, 18 Oct 2018 20:20:33 +0000 Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id 6C50A22B12; 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Intel Mac OS X 10.13; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <08adbe4e-38f8-2c73-55f0-591392371687@2ndquadrant.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On 18/10/2018 22:17, Peter Eisentraut wrote: > On 17/10/2018 23:51, Andres Freund wrote: >>> __builtin_types_compatible_p(const char *, char *) returns false (0) for me. >> >> Right, that's why I added a const, inside the macro, to the type >> specified in the unconstify argument. So typeof() yields a const char *, >> and the return type is specified as char *, and adding a const in the >> argument also yields a const char *. > > Yeah, that works. The C++-inspired version also allowed casting from > not-const to const, which we don't really need. > Attached is my previous patch adapted to your macro. Oh, I forgot to mention, your version doesn't work for this code in pqexpbuffer.c: str->data = (char *) oom_buffer; That's probably not a big deal though. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services