220 6861 article Path: news.gmane.org!not-for-mail From: "Billy O'Neal" Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Proposal: Class Frames to inject prefabricated features into classes Date: Tue, 1 Oct 2013 13:53:12 -0700 Lines: 289 Approved: news@gmane.org Message-ID: References: <27c90f45-8ae6-44c1-8755-2b4cece26bcb@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=089e0129478479a30e04e7b426d3 X-Trace: ger.gmane.org 1380660830 32011 80.91.229.3 (1 Oct 2013 20:53:50 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 1 Oct 2013 20:53:50 +0000 (UTC) To: std-proposals Original-X-From: std-proposals+bncBDKLBLVE6ADBBYPMVSJAKGQESBOBBQY@isocpp.org Tue Oct 01 22:53:55 2013 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ie0-f199.google.com ([209.85.223.199]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VR6x8-0007Xs-JR for gclcip-std-proposals@m.gmane.org; Tue, 01 Oct 2013 22:53:54 +0200 Original-Received: by mail-ie0-f199.google.com with SMTP id e14sf25236848iej.6 for ; Tue, 01 Oct 2013 13:53:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :x-original-sender:x-original-authentication-results:reply-to :precedence:mailing-list:list-id:list-post:list-help:list-archive :list-subscribe:list-unsubscribe:content-type; bh=wJ94CmHYhzrV5xTRXwZKqqF3roko+Vhzq6H/eTCTSgA=; b=CuoEwF6Oz+vz9jc/G9PJNJdxw7Q7PO2AGVnAn+l2yjosU9OY1yTe1HOsp89uNb9/lI pmjRqQB6GgPe8sKxPBI7Q/E1ezs3+7kgKSvGbYKEOnHwsM8ywLVtjQ/yn2vkp+ZWA8xE y2TCNCE4udWywcPDh8tictiGfGN2XKTSMvTsrmwLRpZYmY5GYwRlYaZ6dmwJuFYimwp6 OC+XYvWT6zp+FngKnjlCASFhMRmxngbY36mfJmvOJ48Di9Cn6il94e2xIRV7O/6/EiAq ZNzb0+mT28ErbOEvTYYKMRnwFA4XY4eSjNl92ub1rFTdbJAvp+SysK4JGX3a76fD9poU mKdQ== X-Received: by 10.42.191.81 with SMTP id dl17mr17283620icb.15.1380660833579; Tue, 01 Oct 2013 13:53:53 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.50.57.15 with SMTP id e15ls3024472igq.16.canary; Tue, 01 Oct 2013 13:53:53 -0700 (PDT) X-Received: by 10.60.115.164 with SMTP id jp4mr28486250oeb.19.1380660832927; Tue, 01 Oct 2013 13:53:52 -0700 (PDT) Original-Received: from mail-ie0-x229.google.com (mail-ie0-x229.google.com [2607:f8b0:4001:c03::229]) by mx.google.com with ESMTPS id i4si6255913oew.75.1969.12.31.16.00.00 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 01 Oct 2013 13:53:52 -0700 (PDT) Received-SPF: pass (google.com: domain of billy.oneal@gmail.com designates 2607:f8b0:4001:c03::229 as permitted sender) client-ip=2607:f8b0:4001:c03::229; Original-Received: by mail-ie0-f169.google.com with SMTP id tp5so15641586ieb.28 for ; Tue, 01 Oct 2013 13:53:52 -0700 (PDT) X-Received: by 10.50.79.164 with SMTP id k4mr19687277igx.10.1380660832475; Tue, 01 Oct 2013 13:53:52 -0700 (PDT) Original-Received: by 10.43.166.67 with HTTP; Tue, 1 Oct 2013 13:53:12 -0700 (PDT) In-Reply-To: <27c90f45-8ae6-44c1-8755-2b4cece26bcb@isocpp.org> X-Original-Sender: billy.oneal@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of billy.oneal@gmail.com designates 2607:f8b0:4001:c03::229 as permitted sender) smtp.mail=billy.oneal@gmail.com; dkim=pass header.i=@gmail.com; dmarc=pass (p=NONE dis=NONE) header.from=gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: 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:6861 Archived-At: --089e0129478479a30e04e7b426d3 Content-Type: text/plain; charset=ISO-8859-1 How is this different than what you can already do with the existing: template class MoveInjection { T& operator=(T&&) { /*...*/ } } class Client : public MoveInjection { } Billy O'Neal https://github.com/BillyONeal/ http://stackoverflow.com/users/82320/billy-oneal Malware Response Instructor - BleepingComputer.com On Tue, Oct 1, 2013 at 11:33 AM, Mikhail Semenov < mikhailsemenov1957@gmail.com> wrote: > I propose to introduce class frames, which allow to inject features into > classes, which in most cases are not available through inheritance. In > addition, they > don't require virtual functions, which makes them more efficient. > > *Part I* > The frame provides features that are required for a class to be > constructed; it and starts with a header: > *class FrameName(class T) > *or > *struct FrameName(class T)* > > > For example: > > *class MoveInjection(class T) > { > public: > T(); // to be defined in the class > T(const T&);// to be defined in the class > virtual ~T();// to be defined in the class > void swap(T&);// to be defined in the class > * > > * T(T&& b):T() // is provided for the class > { > swap(b); > }* > > * T& operator=(const T& b) // is provided for the class > { > T c(b); > swap(c); > return *this; > }* > > * T& operator=(T&& b) // is provided for the class > { > swap(b); > return *this; > } > };* > > > The MoveInjection frame allows to create a class with a move constructor > and assignment much easier: the programmer > has to provide the definitions for T(), T(const& T&), ~T() and swap: > > *class A using MoveInjection > { > public: > A() {...} > A(const A& a) { ... } > virtual ~A() { ... } > void swap(T& a) { ... } > };* > > > > The class frame may contain static objects: > > *class AddInjection(class T) > { > static friend T operator+(class T& a, class T& b); > };* > > > *Part II* > > If the parameter inside a frame is not used, it can be dropped. In this > case, > it is possible to write: > > *class IntegralInjection() > { > public: > double integral(std::function, double a, double b); > };* > > Such class frames can be used in a similar way: > *class B using IntegralInjection > { > public: > double integral(std::function, double a, double b) > { > ... > } > ... > };* > > But it is also possible to use such class frames in templates: > > *template Integrate > ...* > which means that this template requires the class to contain an integral > function, which the given header. > > *Additional features of class frames* > > (1) It should be possible to use several frames to inject various features > into a class. > > (2) A class frame itself can be defined in a template: > *template* > *class SpecialInjection(class B)* > *{* > *....* > *};* > > ** > > > > > > -- > > --- > 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. > Visit this group at > http://groups.google.com/a/isocpp.org/group/std-proposals/. > -- --- 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. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/. --089e0129478479a30e04e7b426d3 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
How is this different than what you can already do wi= th the existing:
=A0
template <typename T>
<= div>class MoveInjection
{
=A0=A0=A0 T&=A0operator= =3D(T&&) { /*...*/ }
}
=A0
class Client : public MoveInjection<Clien= t>
{
=A0
}
=A0

Billy O&#= 39;Neal
Malware Response Instructor - BleepingComputer.com


On Tue, Oct 1, 2013 at 11:33 AM, Mikhail= Semenov <mikhailsemenov1957@gmail.com> wrote:
I propose to introduce class frames, which allow to i= nject features into classes, which in most cases are not available through = inheritance. In addition, they
don't require virtual function= s, which makes them more efficient.
=A0
Part I
The frame provides features that are required for a class to be construct= ed; it and starts with a header:
class FrameName(class T)
or
struct FrameName= (class T)


For example:

class MoveInjecti= on(class T)
{
public:
=A0 T();=A0=A0=A0=A0=A0=A0=A0 // to be defin= ed in the class
=A0 T(const T&);// to be defined in the class
=A0 virtual ~T();// to= be defined in the class
=A0 void swap(T&);// to be defined in the c= lass
=A0

=A0 T(T&& b):T() // is provided= for the class
=A0 {
=A0=A0=A0=A0 swap(b);
=A0 }

=A0 T& o= perator=3D(const T& b) // is provided for the class
=A0 {
=A0=A0= =A0=A0 T c(b);
=A0=A0=A0=A0 swap(c);
=A0=A0=A0=A0 return *this;
= =A0 }

=A0 T& operator=3D(T&& b) // is pr= ovided for the class
=A0 {
=A0=A0=A0=A0 swap(b);
=A0=A0=A0=A0 return *this;
=A0 }
};=


The MoveInjection frame allows to create a class with a= move constructor and assignment much easier: the programmer
has to prov= ide the definitions for T(), T(const& T&), ~T() and swap:

class A using MoveInjection
{
public:
=A0=A0 A() {...}<= br>=A0=A0 A(const A& a) { ... }
=A0=A0 virtual ~A() { ... }
=A0= =A0 void swap(T& a) { ... }
};

=A0

The class fr= ame may contain static objects:

class AddInjection(class T)
{
=A0=A0 static friend T opera= tor+(class T& a, class T& b);
};


P= art II

If the parameter inside a frame is not used, it c= an be dropped. In this case,
it is possible to write:

class IntegralInjection()
{
pu= blic:
=A0=A0=A0 double integral(std::function<double(double)>, dou= ble a, double b);
};

Such class frames can be used in a s= imilar way:
class B using IntegralInjection
{
public:
=A0=A0=A0 double= integral(std::function<double(double)>, double a, double b)
=A0= =A0=A0 {
=A0=A0=A0=A0=A0 ...
=A0=A0=A0 }
=A0=A0=A0 ...
};

But it is also possible to use such class frames in templates:

template Integrate<class A using IntegralInjection>
...=

which means that this template requires the class to cont= ain an integral function, which the given header.
=A0
Additional features of class frames
=A0
(1) It=A0should be=A0possible to use several frames to inject vari= ous features into a class.
=A0
(2) A class frame itsel= f can be defined in a template:
template<class A>
class Speci= alInjection(class B)
{
....
};
<= font color=3D"#888888">

=A0

=A0

=A0

--
=A0
---
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-proposals+unsubscribe@isocpp.org.
To post to this group, send email to std-proposals@isocpp.org.
Visit this group at http://groups.google.com/a/isocpp.org/gro= up/std-proposals/.

--
 
---
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-proposals+unsubscribe@isocpp.org.
To post to this group, send email to std-proposals@isocpp.org.
Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/<= /a>.
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