220 10458 <2ce5f43b-9a89-457c-afa1-71ba867e66ef@isocpp.org> article Path: news.gmane.org!not-for-mail From: maksimpustovoyt@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Add compiler time attributes like c# Date: Wed, 30 Apr 2014 17:43:10 -0700 (PDT) Lines: 199 Approved: news@gmane.org Message-ID: <2ce5f43b-9a89-457c-afa1-71ba867e66ef@isocpp.org> References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_2930_9961398.1398904990735" X-Trace: ger.gmane.org 1398905000 21709 80.91.229.3 (1 May 2014 00:43:20 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 1 May 2014 00:43:20 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCRP3Q4MT4MRBH5RQ2NQKGQETBI4XFA@isocpp.org Thu May 01 02:43:15 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-oa0-f69.google.com ([209.85.219.69]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Wff5l-0004Jw-9j for gclcip-std-proposals@m.gmane.org; Thu, 01 May 2014 02:43:13 +0200 Original-Received: by mail-oa0-f69.google.com with SMTP id i7sf13147795oag.0 for ; Wed, 30 Apr 2014 17:43:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to: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 :content-type; bh=S/ihbpZbAN3TS8w+fMsvBtk/xinPHFOkC7vqWZo/ATg=; b=Unyw05nz9ym5gCdDpP2flXwSdvmPu3MsvPA6yMxwsIKDGzBb1YOg2OoZ6V/RhNPysy /y08S3ML+OJ5YsTbYd/PW2OzwpNakVTACCfgw8GayGcoGpgwaO8hm5evGS+7A3z7qon7 0vIGKQZHdvSFP+AVw0NY+AfX0zh0BWfuC6yO3SBxZVWFnrfkpwUsawPge+DVnu2CDB1B YU2SwfoocrNbVsKKIGB+T096ed0R2YrxDZRzg9pgwpMMdOjiyiFAS55q9Ky7WaP/3G/B wwXheU3O9kSyUQPHYDA7A66fPPNxWpnw4Hvk+391NXFyZns1/gcuTcAriJkjAjWOQ0rZ zqCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to: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:content-type; bh=S/ihbpZbAN3TS8w+fMsvBtk/xinPHFOkC7vqWZo/ATg=; b=XV5lc/PE1mYs+KaKJI54NPxDaa4bTuwSOKCCtP2i4HVRwwXc+CdAdldexBjtkC7E1a nSUdUNsdiQcxqTlV7Ysh/Piz4hKMu5rvNeB7wmYAhHI+EykogYJOWjPZIeFqQKC5smWw mxrKJ61ptaYr/q3toCRGf5asAKYtV7p0MmfONwq2C46E9cW4j1B+w4KO40k6G0+MsJUA nllaoHkUowskmrtwVMQg0t5m1frkinTsTZ2kmj6U4DD9nTM1igPwAucCDzyCVs1CXMRe 6xW+Or5k2Q4qFBnloKjWY2epHDqhnCWfXVw5NZ6JaXFpk/mFM3/yb3GH/UiE45gHFMd5 wi3A== X-Gm-Message-State: ALoCoQl28iJn2O4JM35h6yhIpZ6sdiZMNB1E9iSpB8wFhMFlW/iEO1DT6iym7S/9YbsSjtgjcFY5 X-Received: by 10.43.117.71 with SMTP id fl7mr3950340icc.24.1398904992289; Wed, 30 Apr 2014 17:43:12 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.182.138.69 with SMTP id qo5ls442286obb.34.gmail; Wed, 30 Apr 2014 17:43:11 -0700 (PDT) X-Received: by 10.182.243.227 with SMTP id xb3mr55355obc.17.1398904991249; Wed, 30 Apr 2014 17:43:11 -0700 (PDT) In-Reply-To: X-Original-Sender: maksimpustovoyt@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:10458 Archived-At: ------=_Part_2930_9961398.1398904990735 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Wednesday, April 30, 2014 8:13:44 AM UTC-4, Klaim - Jo=C3=ABl Lamotte wr= ote: > > C++11 already have =E2=80=8Battributes. See:=20 > en.cppreference.com/w/cpp/language/attributes > Or are you suggesting specific attributes to be standardised? > If yes, then your example is not clear at all to me. > This is different than C++11 attributes. This is extendable Metadata about class which you can use in real time=20 or sometimes it's called "reflection" For example, I want to print my object in nice format. I can do something= =20 like that: *[AttributeExtension]* // This predefine attribute tells compiler that this= =20 class can be used as an Attribute for other classes: struct MyAttribute { string Name; string Description; MyAttribute(string name; string description=3D "") : Name(name),=20 Description(description) {} } *[AttributeExtension]* // This predefine attribute tells compiler that this= =20 class can be used as an Attribute for other classes: struct AgeRange {=20 int Minum; int Maximum; AgeRange(int minum; int maximum) Minum(minum), Maximum(maximum) {} } .... some time later in code... *[METADATA(true)]* // tells compiler to geneate meta data about class Perso= n // Compiler generates static Metadata=20 classes such as Person::Class::MyAttribute,=20 Person::Member::FirstName::MyAttribute, ... *[MyAttribute("Person", "Person Info")]* // calls constructor=20 Person::Class::MyAttribute::MyAttribute("Person", "Person Info") struct Person { [MyAttribute("Fist Name")] // calls constructor=20 Person::Member:FirstName::MyAttribute::MyAttribute("Fist Name") string FirstName; [MyAttribute("Last Name", "Person's last name")] // calls=20 constructor Person::Member:FirstName::MyAttribute::MyAttribute("Last Name",= =20 "Person's last name")=20 string LastName; [AgeRange(18,50)] // calls constructorPerson::Member:: AgeRange::AgeRange(18,50)=20 int ValidAge; } .... some time later in code... bool CanRegisterPerson(Person &person) {=20 if (person.ValidAge < *Person::Member::ValidAge::AgeRange::Minimum*)=20 return false;=20 if (person.ValidAge > *Person::Member::ValidAge::AgeRange::Maximum*)=20 return false; return true; } bool RegisterPerson(Person &person) {=20 if (!CanRegisterPerson(person)) { printf("Cannot register person %s:%s, %s:%s because age %d must be in=20 between %d and %d\n" ,*Person::Member::FirstName::MyAttribute::Name*.c_str() // compiler=20 generate static data member Name () ,person.FistName.c_str() ,*Person::Member::LastName::MyAttribute::Name*.c_str() ,person.LastName.c_str() =20 ,person.Age ,*Person::Member::ValidAge::AgeRange::Minimum* ,*Person::Member::ValidAge::AgeRange::Maximum* return false; ); return true; =20 } }=20 --=20 ---=20 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 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-proposa= ls/. ------=_Part_2930_9961398.1398904990735 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Wednesday, April 30, 2014 8:13:44 AM UTC-4, Kla= im - Jo=C3=ABl Lamotte wrote:
= C++11 already have =E2=80=8Battributes. See: en.cppreference.com/w/cpp/language/attributesOr are you suggesting specific attributes to be standardised?
If yes, then your example is not clear at all to me.

This is different than C++11 attributes.

This= is extendable Metadata about class which you can use in real time or = sometimes it's called "reflection"

For example, I want to print = my object in nice format. I can do something like that:

[Attr= ibuteExtension] // This predefine attribut= e tells compiler that this class can be used as an Attribute for other clas= ses:
struct MyAttribute {
    string Name;
&= nbsp;   string Description;
    MyAttribute(str= ing name; string description=3D "") : Name(name), Description(description) = {}
}
[AttributeExtension] //= This predefine attribute tells compiler that this class can be used as an = Attribute for other classes:
struct AgeRange { 
 &nb= sp;  int Minum;
 int Maximum;
 AgeRange(int minum; int= maximum)  Minum(minum), Maximum(maximum) {}
}


<= font color=3D"#134f5c">... some time later in code...

[METADATA(true)] // tells compiler to geneate meta data about class Person
      &= nbsp;           &nbs= p;            &= nbsp; // Compiler generates static Metadata classes such as Person::Class::MyAttribute, Person::M= ember::FirstName::MyAttribute, ...

[MyAttribute("Person", "Person Info")] // calls constructor Person::Class::MyAttrib= ute::MyAttribute("Person", "Person Info")
struct Person { [MyAttribute("Fist Name")] // calls construc= tor Person::Member:FirstName::MyAttribute::MyAttribute("Fist Name")<= br> string FirstName;
 [MyAttribute("Last Name", "Person's las= t name")] // calls constructor Person::Member:= FirstName::MyAttribute::MyAttribute("Last Name", "Person's last name") 
 string LastName;
 [AgeRange(18,50)] // calls constructorPerson::Member::AgeRange::AgeRange(18,50) 
 int ValidAge;
}
=


... some time later in code...

= bool CanRegisterPerson(Person &person) { 
 if (person.Vali= dAge < Person::Member::ValidAge::AgeRange::Minimum= ) return false; 
 if (person.ValidAge > Person::Mem= ber::ValidAge::AgeRange::Maximum) return false;
 retu= rn true;
}

bool RegisterPerson(Person &person) { 
&nbs= p;if (!CanRegisterPerson(person)) {
  printf("Cannot register = person %s:%s, %s:%s because age %d must be in between %d and %d\n"
 = ;  ,Person::Member::FirstName::MyAttribute::Name.c_str() // compiler generate static data member Name ()
=    ,person.FistName.c_str()
   ,Pe= rson::Member::LastName::MyAttribute::Name.c_str()
 &n= bsp; ,person.LastName.c_str()   
   ,= person.Age
   ,Person::Member::ValidAge::Age= Range::Minimum
   ,Person::Member::Valid= Age::AgeRange::Maximum
   return false;
=   );
  return true;  
 }


} 

--

---
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.
Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/<= /a>.
------=_Part_2930_9961398.1398904990735-- .