220 38614 article Path: news.gmane.org!.POSTED!not-for-mail From: mihailnajdenov@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: new feature: declare data that replaces the previous one, or similar situation.... Date: Tue, 12 Jun 2018 00:28:30 -0700 (PDT) Lines: 127 Approved: news@gmane.org Message-ID: References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_97792_254518234.1528788510279" X-Trace: blaine.gmane.org 1528788386 9631 195.159.176.226 (12 Jun 2018 07:26:26 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 12 Jun 2018 07:26:26 +0000 (UTC) Cc: rmbeer2@gmail.com To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCUJ3A7GRAPRBH7M7XMAKGQEW6REB4Q@isocpp.org Tue Jun 12 09:26:22 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yw0-f198.google.com ([209.85.161.198]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fSdh7-0002Mv-7z for gclcip-std-proposals@m.gmane.org; Tue, 12 Jun 2018 09:26:21 +0200 Original-Received: by mail-yw0-f198.google.com with SMTP id l125-v6sf21118480ywc.15 for ; Tue, 12 Jun 2018 00:28:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:x-original-sender:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe; bh=94L7UkyJjdy/f6Z9ItFv0dGtVQvqIP4ubogHLlRUh/0=; b=Vj0c1xfw67iFwgqjbIWTMHYnfaBfnG9CCtzHxauSM+Iah6vujOvbfOX/HhFSdAXqnC mKdf+x12nytQl57k3+0RBKm5Sd9iepk9U+EIA6Gy2P+h1eXX+0F1LvqfVEoLvQqrX3ro /V3zvyVov7usIurRu6jZscNkGaBTIEw65vhA+qoNfGMC8GVn++yjZ8jN3Ko0nFgT3BM6 yk/XDm6UV8OiYPGse5WO/feWDmQDTAzM+bYsoeFyO2A2GMq+5hC2SeWP35Q/mWWA3n1o HXh5qBPR5V9czPIeg7BojBvt8RdYxoYTov9IqXuNCZ4p8SdthcxGs3m7jS8ECWAjI+JE aKjw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:x-original-sender:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe; bh=94L7UkyJjdy/f6Z9ItFv0dGtVQvqIP4ubogHLlRUh/0=; b=I7ebzS88Bijx+uhTCs4CFG2tz46DQKdOdTHBMkZRaTDjyJTTJ12n3+kbTAoTU05pYg Zu5/kGlES8H3EF7lxyqllCHqFANSTFxcqm7Jn3pcJxoezqD6PycrsU+qMy6kaFyReFxU 7etaMQsvu7qI4H6XhRMFGyMpXpPX+Q6HKig1Cqtweku3gt40C+0UDPXSja46NkrUJU78 TeecLVQo4pNTmUoXH+ufydfnAYg54k4GWiexKvJDC2Shsz0fbtd4ix5ioTdK74kymOjq e3NAOSxxwvG0/uWmIWNnESPl/XPkMJahhjW1wQZvNaCEjSF3dfIy3FBfyykr6Gbxacg1 PfCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:x-original-sender:reply-to :precedence:mailing-list:list-id:x-spam-checked-in-group:list-post :list-help:list-archive:list-subscribe:list-unsubscribe; bh=94L7UkyJjdy/f6Z9ItFv0dGtVQvqIP4ubogHLlRUh/0=; b=Ws67S6EX4+/bzZG88t/tgOplhf54XYFptSBNnyql/W9OwsphKTtXcHjIMXZ63Rxs08 6FbxbmW/j/lZv6t4Pe9r6kCZrijXrlxW3xt7IKIUrZ5Mzv4ZqA+I/LPzTiIEaK75vsHF qZIhb7IYrM8s/lL16EZYN9SlB5M1Y0doca5MFUnFDBUeehQba44HGCDVJv5cEI9Lu0uz 9DpYYbjBI8tbzhcwbaejDjh5CXv3/cs0K+WMEmB/7UeR9wAiWEPgt06RvZUVPnDRF+qu 6kGn/8HgBy98/3Gq/AOVYTC5mnlfwI84V8q6TJpsy8oRQJDJVn33VnODdL7ZIQq7dAKD 7Hig== X-Gm-Message-State: APt69E3FMfFSYvevWeXdnHJJkvwOjOqkp8hRpktB+qMKUKVI47sV0DQl ScMQC7vjFg5ACnAA9RHe9bvXRQ== X-Google-Smtp-Source: ADUXVKJckBk9SR0KUieDwRNkFeP6tPnJCuhyjyubp22iKR3bMLSqD8rXbbwafF6UiEl4mYj4b1ItYA== X-Received: by 2002:a25:d4b:: with SMTP id 72-v6mr6287766ybn.55.1528788512135; Tue, 12 Jun 2018 00:28:32 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 2002:a81:7354:: with SMTP id o81-v6ls133540ywc.18.gmail; Tue, 12 Jun 2018 00:28:31 -0700 (PDT) X-Received: by 2002:a81:3487:: with SMTP id b129-v6mr1330691ywa.13.1528788510996; Tue, 12 Jun 2018 00:28:30 -0700 (PDT) In-Reply-To: X-Original-Sender: MihailNajdenov@gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:38614 Archived-At: ------=_Part_97792_254518234.1528788510279 Content-Type: multipart/alternative; boundary="----=_Part_97793_1441088912.1528788510279" ------=_Part_97793_1441088912.1528788510279 Content-Type: text/plain; charset="UTF-8" *Solution 2* template class B { public: B(int i=1) : a(i) { } void f2() { std::cout << "A:" << a.z << std::endl; } // virtual A a; // Use A only from B T a; }; class D : public B { public: D() : B(3) { } void f2(){ std::cout << "C+A:" << a.z << std::endl; B::f2(); } // virtual C a; // Use C+A only from D }; *Solution 3* class B { public: B(A* a_) : a(a_) { } B() : a(new A(1)) { } void f2() { std::cout << "A:" << a->z << std::endl; } // virtual A a; // Use A only from B std::unique_ptr a; }; class D : public B { public: D() : B(new C(3)) { } void f2(){ std::cout << "C+A:" << a->z << std::endl; B::f2(); } // virtual C a; // Use C+A only from D }; *Solution 4* Develop in terms of interfaces only -- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/bebc25db-8a70-4f45-9694-f5e517dccbce%40isocpp.org. ------=_Part_97793_1441088912.1528788510279 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Solution 2<= /b>


template<class T>
class B {
public:
=C2=A0=C2=A0= =C2=A0 B(int i=3D1) : a(i) { }
=C2=A0=C2=A0=C2=A0 void f2() {
=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 std::cout << "A:" <= < a.z << std::endl;
=C2=A0=C2=A0=C2=A0 }
//=C2=A0=C2=A0=C2= =A0 virtual A a; // Use A only from B
=C2=A0=C2=A0=C2=A0 T a;
};
class D : public B<C&g= t; {
public:
=C2=A0=C2=A0=C2=A0 D() : B<C>(3) { }
=C2=A0=C2= =A0=C2=A0 void f2(){
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 std::cou= t << "C+A:" << a.z << std::endl;
=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 B::f2();
=C2=A0=C2=A0=C2=A0 }
//=C2= =A0=C2=A0=C2=A0 virtual C a; // Use C+A only from D
};
=

Solution 3
<= br>

class B=C2=A0=
{
public:
=C2=A0 B(A* a_) : a(a_) { }
=C2=A0 B() = : a(new A(1)) { }
=C2=A0 void f2() {
=C2=A0=C2=A0 std::cout << = "A:" << a->z << std::endl;
=C2=A0 }
// vi= rtual A a; // Use A only from B
=C2=A0 =C2=A0 std::unique_ptr<A> a= ;
};

class D : public B=C2=A0
{<= br>
public:
=C2=A0 D() : B(new C(3)) { }
=C2=A0 void f2(){
= =C2=A0 =C2=A0 std::cout << "C+A:" << a->z <<= std::endl;
=C2=A0 =C2=A0 B::f2();
=C2=A0 }
// virtual C a; // = Use C+A only from D
};

Solution 4

Develop in t= erms of interfaces only

--
You received this message because you are subscribed to the Google Groups &= quot;ISO C++ Standard - Future Proposals" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposa= ls+unsubscribe@isocpp.org.
To post to this group, send email to std-proposals@isocpp.org.
To view this discussion on the web visit https://groups.google.= com/a/isocpp.org/d/msgid/std-proposals/bebc25db-8a70-4f45-9694-f5e517dccbce= %40isocpp.org.
------=_Part_97793_1441088912.1528788510279-- ------=_Part_97792_254518234.1528788510279-- .