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[80.12.242.128]) by mx.google.com with ESMTP id x2si3866077eef.136.2013.05.25.05.25.21 for ; Sat, 25 May 2013 05:25:21 -0700 (PDT) Received-SPF: neutral (google.com: 80.12.242.128 is neither permitted nor denied by best guess record for domain of vicente.botet@wanadoo.fr) client-ip=80.12.242.128; Original-Received: from iMac-de-Vicente-Botet-Escriba.local ([2.13.6.91]) by mwinf5d41 with ME id gCRJ1l00E1xq0tN03CRLyo; Sat, 25 May 2013 14:25:20 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 In-Reply-To: X-Original-Sender: vicente.botet@wanadoo.fr X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 80.12.242.128 is neither permitted nor denied by best guess record for domain of vicente.botet@wanadoo.fr) smtp.mail=vicente.botet@wanadoo.fr 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:4572 Archived-At: This is a multi-part message in MIME format. --------------030901000208050905050609 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Le 24/05/13 22:24, Nevin Liber a =E9crit : > On 24 May 2013 14:02, Vicente J. Botet Escriba=20 > > wrote: > > > Returning future>>> would provide > efficiency and safety. > > > If you are going to go this route, please don't use pair. It is much=20 > better to have field names that mean something. I agree that using accessors would be more readable, hide the=20 representation and in addition it could provide a value function that=20 would retrieve the first value set. The quiz would be to find a name for=20 the class providing these accessors ;-) Any suggestion is welcome. template class ??? { public: vector vector() && noexcept; R value() &; }; auto f =3D when_any(f1, f2); .... int i =3D f.get().value(); // efficiency vector v =3D f.get().vector(); // safety The following is safe as the futures are transfered to the new variable auto f =3D when_any(f1, f2).to_vector(); But should the following compile int i =3D when_any(f1, f2).value(); With the following declaration the preceding statement must fail at=20 compile time, isn't it? R value() &; Vicente --=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/?hl=3Den. --------------030901000208050905050609 Content-Type: text/html; charset=ISO-8859-1
Le 24/05/13 22:24, Nevin Liber a écrit :
On 24 May 2013 14:02, Vicente J. Botet Escriba <vicente.botet@wanadoo.fr> wrote:

Returning future<pair<size_t, vector<future<R>>>> would provide efficiency and safety.

If you are going to go this route, please don't use pair.  It is much better to have field names that mean something.

I agree that using accessors would be more readable, hide the representation and in addition it could provide a value function that would retrieve the first value set. The quiz would be to find a name for the class providing these accessors ;-)  Any suggestion is welcome.

template <typename R>
class ???
{
public:
  vector<future<R> vector() && noexcept;
  R value() &;
};

auto f = when_any(f1, f2);
...
int i = f.get().value(); // efficiency
vector<future<R> v = f.get().vector(); // safety

The following is safe as the futures are transfered to the new variable
  auto f = when_any(f1, f2).to_vector();

But should the following compile
  int i = when_any(f1, f2).value();

With the following declaration the preceding statement must fail at compile time, isn't it?
  R value() &;

Vicente

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