April 2010 - Boost - lists.boost.org

[mpl] has_function
by Lorenzo Caminiti 02 Apr '10

02 Apr '10

Hello all, Is there a way I can check if a class has a given member function using metaprogramming? What I need is to check at compile-time if a function is overriding a virtual function or not. In the example below, z::f is overriding x::f but not y::f (which does not exist) and the compiler knows that -- is there a way I can extract that information from the compiler? struct has_function<class Base, ... /* other parameters */ > { ... /* some implementation */ }; struct x { virtual void f() {} }; struct y { virtual void g() {} }; struct z: x, y { void f() { cout << has_function<x, &z::f>::value << endl; // print 1 cout << has_function<y, &z::f>::value << endl; // print 0 } }; (This does not compile -- I do not know how to program it so it compiles -- but it should give the idea of what I am looking for.) Thank you very much. Lorenzo

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Re: [boost] [GSOC] summary of BigInt library details
by Ankit Malpani 02 Apr '10

02 Apr '10

hello all, thanks for the prompt replies. here are some issues (some carry forwarded from previous mail) which need addressing. [Scott McMurray wrote] >For example, GMP has a function mpz_addmul(x,y,z) that we would rather >write as x += y*z; > >My idea for the use of Boost.Proto is for its expression template >transformation features to rewrite the easy-to-use syntax to take >advantage of such optimized backend features. thank you, that really clarified the issue rearding basing the frotend off Boost.Proto. My question is - boost already has done work for handling big_integral [boost/mpl/math/big_integral/] (saw it in archives dating back to 2005 refer [1] ) so which backend option is more advisable:- a) use these functions based off boost/mpl/math/big_integral/. if so can someone please give a link to its documentation. or b) use a backend developed by me .(probably with the help non boost.math but standard c++ libraries) [Bruno Lalande wrote:] >So to summarize, I can see 3 distinct actions: >1) implement your BigInt backend >2) provide a Boost.Math binding compliant interface for this backend >3) implement a frontend for Boost.Math binding based on Boost.Proto thanks for summing it up so precisely :) could u please elaborate more on point 2, does it mean that the interface being provided should be similar to those provided by Boost.Math ? here is my refined project idea once again:- 1. provide the frontend which takes care of expressions like z += y*z (using Boost.Proto) 2. implement backend using :- a) an implementation developed by me (using simple standard c++ library functions). or b) using boost/mpl/math/big_integral/ . (if so please give me a link to its documentation) moreover, is there any Boost specific format to be followed for submission of the project idea? i hope the community and gsoc mentors will help me out with these queries soon. [1] http://lists.boost.org/Archives/boost/2005/10/subject.php Cheers! Ankit Malpani 3rd Year Undergraduate | BE. Hons Computer Science BITS Pilani Goa Campus

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[1.43.0] Change of release schedule
by Beman Dawes 02 Apr '10

02 Apr '10

To allow a large block of weekend time for last tweaks, from now on the release schedule is going to be changed to the first Monday of the second month of each quarter. Updated calendar 1.43.0: http://www.boost.org/development/index.html General date info: http://svn.boost.org/trac/boost/wiki/ReleaseSchedule --Release managers

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[range][string_algo] Conflict between algorithm names
by Jeremiah Willcock 02 Apr '10

02 Apr '10

When I try to include both Boost.Range algorithms (in the current trunk version) and Boost.Algorithm, using a file such as the following: #include <boost/algorithm/string.hpp> #include <boost/range/algorithm.hpp> I receive several errors about duplicate definitions. I am using gcc 4.1.2 on Linux. ./boost/range/algorithm/find.hpp:28: error: ‘template<class SinglePassRange, class Value> typename boost::range_iterator::type boost::find(SinglePassRange&, const Value&)’ conflicts with previous using declaration ‘template<class RangeT, class FinderT> boost::iterator_range<typename boost::range_iterator<C>::type> boost::algorithm::find(RangeT&, const FinderT&)’ ./boost/range/algorithm/lexicographical_compare.hpp:28: error: ‘template<class SinglePassRange1, class SinglePassRange2> bool boost::lexicographical_compare(const SinglePassRange1&, const SinglePassRange2&)’ conflicts with previous using declaration ‘template<class Range1T, class Range2T> bool boost::algorithm::lexicographical_compare(const Range1T&, const Range2T&)’ ./boost/range/algorithm/lexicographical_compare.hpp:42: error: ‘template<class SinglePassRange1, class SinglePassRange2, class BinaryPredicate> bool boost::lexicographical_compare(const SinglePassRange1&, const SinglePassRange2&, BinaryPredicate)’ conflicts with previous using declaration ‘template<class Range1T, class Range2T, class PredicateT> bool boost::algorithm::lexicographical_compare(const Range1T&, const Range2T&, PredicateT)’ The using declarations mentioned in the error message are in files such as boost/algorithm/string/find.hpp. Is there a workaround or easy fix for this? -- Jeremiah Willcock

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[range] Merging algorithms into release branch and <boost/detail/algorithm.hpp>
by Jeremiah Willcock 02 Apr '10

02 Apr '10

The release branch's version of <boost/detail/algorithm.hpp> contains several range versions of STL algorithms that duplicate those in the new version of Boost.Range. The trunk version has removed these duplicate algorithms (in r60919), using Boost.Range instead. This note is to inform whoever merges the algorithms in Boost.Range into the release branch to merge r60919 as well to avoid duplicate function errors. -- Jeremiah Willcock

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GSOC 2010 :BOOST Heaps and Queues
by shivaraaj kotini 02 Apr '10

02 Apr '10

Hi all, Im Shivaraaj, Im from Birla Institute of Technology Science (B.I.T.S) pilani, India. I recently came across GSOC 2010 and Im very interested in it.Though Im late I dont want to give up and continue discussing ideas before submitting an application. Im very much interested in BOOST Heaps and Queues project. My idea was to create a replica of JSDL api in BOOST (not completely but the useful part related to our project) and providing more features by adding 'mutable' to the objects created and there by we can do updations to existing objects. I feel we can inherit and create a lot of standard data structures apart from heaps. And within heaps we can create all different types of heaps and pull under a common interface. Thank You, Shivaraaj Kotini.

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Release 1.12 of the C++ Middleware Writer on line
by Brian Wood 02 Apr '10

02 Apr '10

B"H Release 1.12 of the C++ Middleware Writer is now on line. This release fixes several bugs and adds support for the following: 1. Multiple inheritance, but we don't support virtual inheritance yet. G-d willing, we'll add that later. 2. boost::scoped_ptr, auto_ptr/unique_ptr. 3. Accounts An account is now needed to use the command line interface of the C++ Middleware Writer. When an account is created, a directory will be associated with the account. That directory is reused with each request and only the input files that have changed since your last request are transmitted. The command line interface config file, direct.cfg, refers to an Account-Number. That file has to be updated after you set up an account. Use this page -- http://webEbenezer.net/cgi-bin/account.cgi -- to set up an account. Setting up an account is currently trivial -- no questions asked -- just click the button. There's an example of the multiple inheritance and scoped_ptr support here -- http://webEbenezer.net/release/112.example . Cheers, Brian Wood http://www.webEbenezer.net (651) 251-9384

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Transfer of Maintenance Rights
by Stewart, Robert 01 Apr '10

01 Apr '10

Dave asked for a policy proposal for how Boost library maintenance rights may be transferred. Edward Diener declined, so I'll offer one and go a little further while I'm at it. Consider the following as a replacement for the text at <http://www.boost.org/community/reviews.html#Maintainer>. _____________________________ Library Author's Responsibilities By submitting a library to Boost, you agree to put the library and its documentation under a Boost-compatible license, if it is accepted. If your library is accepted, you are free to change it any way you wish. Indeed, we encourage you to make constant improvements. However, because peer review is an important part of the Boost process, please consider getting Boost community feedback before making substantial changes to the interface of your library. Furthermore, if your library is accepted, you agree to be the library maintainer or to find a qualified volunteer to serve in your stead. You may, of course, assemble a qualified group to act as maintainers of your library, regardless of whether you continue to be a maintainer. Library Maintainer's Rights and Responsibilities As a library maintainer, you agree to provide timely support to users of the library, and to fix bugs and release those fixes in a timely fashion. You also agree to consider making library enhancements and improvements. Note that others may offer and even commit patches to a library you maintain, provided the patch is posted to the Boost Developer's mailing list for approval and is not rejected by anyone within a reasonable time. If you find that you can no longer fulfill your responsibilities as maintainer of a library, you are responsible to advertise this to the Boost community. If you are the sole maintainer, you are responsible to find a replacement. If for some reason you fail to fulfill your responsibilities as maintainer of a library, as judged by the Boost community, whether through willful neglect or otherwise, you agree to allow the Boost community to provide a suitable replacement. _____ Rob Stewart robert.stewart(a)sig.com Software Engineer, Core Software using std::disclaimer; Susquehanna International Group, LLP http://www.sig.com IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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GSOC Proposal :
by abhijith reddy 01 Apr '10

01 Apr '10

Hello I am Abhijith Reddy a 3rd year undergrad student from India and my idea for this year's GSOC is to implement an efficient prime factorization (large numbers) class that could be integrated into the Math and numerics library of Boost. I have been working on this since 2-3 months as i am currently doing a project on it, so i already have most of the code however its written in a different language(PIKE) since it supports bigint (uses GMP). So for this project I have to implement my own mini bigint class as well. This class will be relatively smaller compared to any full fledged bigint libraries since the numbers dealt here are relatively small (less than 50 digits) and always positive, so complex algorithms used in normal bigint libraries like (karatsuba,fft based multiplication) can be avoided. So i want to know the scope of this project and any other tips/suggestions would be helpful. Thank you

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GSoC: Boost.Graph library - Graph Connectives
by Yaroslav Vorontsov 01 Apr '10

01 Apr '10

Hello everyone! I'm Yaroslav Vorontsov (or simply Jerry Lee :-)), a student of Computer Science Department of Voronezh State University, Russia. I'm interested in both generic programming and graph theory, and I also would like to participate in Google Summer of Code 2010. I had some experience of generic programming before when I tried to implement my own generic graph library in C# (of course, as a task on one of programming courses at the university). I've read that (quote) "The Boost.Graph library is missing connectives...". I'm quite familiar with C++ and the idea of generic programming and I'm working with some graph theory aspects at the moment, so I want to know: what particular skills (in programming, of course) are needed to develop graph connectives? Thanks in advance, Yaroslav

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