- Boost - lists.boost.org

Thread-safe singleton pattern
by Andrew Chinkoff 22 Mar '10

22 Mar '10

I propose thread safe singleton pattern implementation (see http://www.research.ibm.com/designpatterns/pubs/ph-jun96.txt) I have attached "singleton.hpp" to this letter. Below is the test program: #include <stdio.h> #include <singleton.hpp> class A : public boost::Singleton<A> { // // Only Singleton class can create and delete us! // SINGLETON_IS_MY_FRIEND; public: void foo(){ printf("foo!\n"); } A(){ printf("A()\n"); } ~A(){ printf("~A()\n"); } }; void main() { // It is not compiled: //A a = A::Instance(); // That is exactly as it should be used: A::Instance().foo(); } Test program outputs: A() foo! ~A() My question: Does Boost community think that boost::Singleton is convenient (or successful) solution?

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Re: [boost] GSOC - Boost Libraries
by Andrew Sutton 22 Mar '10

22 Mar '10

> I am Swagat and C++ is my passion. > Hi Swagat, We are glad that you are interested in submitting a proposal for Boost in this year's GSoC program. However, it's hard to comment on your proposal unless you provide details about what you intend to do over the course of the summer. GSoC is a very competitive program, and Boost is particularly selective about awards. Please see [1] for ideas on how to write a good proposal. Andrew Sutton andrew.n.sutton(a)gmail.com [1] https://svn.boost.org/trac/boost/wiki/SoCHints

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Questions about Graph Project
by Liang Dong 22 Mar '10

22 Mar '10

Hi, I am reading the Graph Project's source code. I find there are page rank algorithm, but there is no HITS algorithm and samba. I am curious that if this would be a good topic or everyone just endorse pagerank? best, Liang Dong

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[log] std::endl manipulator does not work, intentional
by Andreas Huber 22 Mar '10

22 Mar '10

Hi Andrey On VS2008, this code ... #include <boost/log/trivial.hpp> #include <ostream> int main() { BOOST_LOG_TRIVIAL(trace) << "This is a" << std::endl << "multiline message"; return 0; } ... fails compilation with the following error: error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'overloaded-function' (or there is no acceptable conversion) Now I do realize that "\r\n" would be a better choice here, as the flushing that comes with std::endl is not necessary. However, some developers in our team seem to prefer std::endl nevertheless. So, the question is: Is this intentional or just an oversight? BTW, only std::endl, std::ends and std::flush don't work, all the other manipulators do. Thanks, -- Andreas Huber When replying by private email, please remove the words spam and trap from the address shown in the header.

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GSOC - Boost Libraries - BIGINT
by swagat konchada 22 Mar '10

22 Mar '10

Hello! I am Swagat and C++ is my passion. I am a student at IIT Roorkee. I would love to work for Boost libraries in GSOC or any other manner. I came to know about GSOC recently. I hope I am not late. Though I initially thought of working for cppnetlib, after seeing the ideas given in the boost gsoc’10 page, I think the project I would like to work the most would be to implement BigInt. I have suffered many times trying to work with big integers, though some code is available on the Internet. A standardized library for BigInt if made enough programmer-friendly would be wonderful. As a programmer who often participates in online competitions, BigInt feature would have been of great use to me and working on it would be more than fun! Also I am free for the summer when I would be staying at my campus the whole time, without distractions. I have attached my resume above. Please comment. ---------------------------------------------------------------------------- A problem is a phenomenon indicating lack of thought. http://letmeseeswagat.blogspot.com/

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GSoC draft proposal: Heaps & Queues library
by Andre Ferreira 22 Mar '10

22 Mar '10

This is only a draft, not the final proposal. Personal Details: Name: André Martins Ferreira Email: greiskul(a)gmail.com University: Universidade Federal do Rio Grande do Sul < www.ufrgs.br > Course: Computer Science Degree Program: Bachelor of Computer Science Availability: About 30 hours a week will be devoted to the project, more if nescessary. Start Date: April 1st End Date: not yet decided Factors of influence: I live in the Southern Hemisphere, so the Summer of Code will be during Winter. While I will have a winter vacation where my attettion will be 100% devoted to the project, it will only last about a month, from July to August. During the rest of the time I will study in the morning, and work on the project on my free time, which luckily this semester entails all afternoons. I have worked during school time in previous semesters, and know that it's possible. Background Information: I am a brazilian computer science student, my course has 9 semesters, I am currently in the 7th. I have been programming for the last 5 years, mostly in C++ but also in Scheme, Lua, and many other languages. I've had an intership in developing parallel programs using MPI, and more recently in supporting an ERP written in C++. My main interest is in algorithms and data structures, but I'm also interested in functional programming languages. My experience with heaps comes from my university classes, Cormen's Introduction to algorithms book, various online sources and personal experimentation. While I have implemented heap data structures before (binary, binomial, skew), I have never integrated them in a single package generic package before and I'm looking foward to learn from it. I would rate my experience in the following technologies this way: 4 C++ 4 C++ Standard Library 2 Boost C++ Libraries 3 Subversion I use mainly Eclipse and Geany for development, but I have also done projects with Visual Studio. For documentation I prefer to use Doxygen. Purpose and goal: Heaps are very useful data structures and are used as building blocks in many algorithms. There are some heap data structures implemented in boost, for use in Boost.Graph for example, but at the moment they are coupled with the library they support. This project's goal is to decouple them into a boost/heaps library, cleaning them up where needed, and completely rewritting them if nescessary. All heaps will provide a common interface where possible, allowing algorithms writters to quickly change the data structure they are using without further changes to their code. The complexity of every operation on every heap will be documented, and tested to ensure correctness. A priority queue wrapper like std::priority_queue will also be provided. Heaps structures that will be provided: binary, binomial, fibonnaci, mutable heaps, suggestions are welcomed. Proposed Milestones and Schedule (work in progress): Binary heap implemented and submitted, possibly on top of STL heap algorithms, to have some foundation for the rest of the work, allowing tests on the other data structures to be compared to a simple but correct heap implementation. Moving heap structures from /boost/pending to the heap library, adapting them to a common interface and cleaning up where nescessary. No rewrites. Binomial Heap implementation. If any of the heap structures from pending were deemed unfit, rewritting them. This proposal is still under work, but I would like feedback from the community, not only on the project but also in the proposal itself.

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GSoC 2010 - Boost.Phoenix
by Thomas Heller 22 Mar '10

22 Mar '10

Hi List, As the subject indicates I am interested in the Boost.Phoenix project for this years summer of code. At first, a little information on me. I am currently studying at University of Erlangen-Nuremberg in Germany. I am learning C++ since 2005. I have experience with Expression Templates. I used them as part of my bachelors thesis: http://www10.informatik.uni- erlangen.de/Publications/Theses/2009/Heller_BA09.pdf Some months ago I discovered the Boost.Proto library. I was trying to implement a DSEL for a GUI description language. This attempt can be found here: http://gitorious.org/phobos/main/trees/c014102b5aefb2592eef625047340fa92d85… However this approach was not continued, and I developed a spirit parser which gives more flexibility in that particular domain. I like the idea of Boost.Phoenix as it is right now. I think an implementation with Boost.Proto seems only natural. I searched the boost SVN repository but i couldn't find the prototypes you mentioned. A link to these would be helpful to be able further look into this project proposal. Regards, Thomas Heller

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queries regarding the BigInt project @ GSoc 2010
by Ankit Malpani 22 Mar '10

22 Mar '10

hello all! i am really interested in developing the proposed BigInt library for Boost as a part of GSoC this summer . Here are a couple of queries i have. 1. With regard to the data structure for handling such integers - are we looking at bit-level implementation(less space and probably more execution time) or digit level manipulation (more space - and probably less execution time). i.e. for an n-digit number is it ok to use up [n/2 to n] bytes of space or necessary to stick to log n amount of space for a BigInt object. 1.1 The arbitrary precision calculations could be implemented using the BigInt data-structure along with a scaling factor variable 2. what all are the expected functions of this library - basic arithmetic(add, subtract ,multiply, divide, modulo, powers) , relational(<=, <, >,>=, !=, ==) , bitwise operation ,and maybe added functionality like gcd and lcm are some of the things i can think of, please do add on to the list . 3. i have no prior experience of using Boost libraries, will this prove to be a problem with regard to this project? Please do refine this design and point out all the flaws in my understanding. Hope to get your replies soon Thanking You, Cheers! Ankit Malpani, 3rd year Undergraduate | BE. (Hons) Computer Science, BITS Pilani - Goa Campus -- Ankit Malpani 3rd Year Undergraduate | BE. Hons Computer Science BITS Pilani Goa Campus

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Trac XMLRPC support
by Vladimir Prus 21 Mar '10

21 Mar '10

Would it be possible to have XMLRPC plugin installed in Boost Trac instance? See: http://trac-hacks.org/wiki/XmlRpcPlugin The installation appears to be fairly simple (and indeed seems to just work somewhere else). This will allow to use third-party tools to grab tickets from Boost Trac, which will hopefully lead to more issues fixed :-) - Volodya

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Boost.Graph and SoC2010
by Cezary Bartosiak 21 Mar '10

21 Mar '10

Hello, I am writing in regards to your SoC2010 participation. I am particurarly interested in developing the Boost Graph library. I have got a working knowledge of graph and networks theory and C++ programming experience. I think I can handle any of the ideas listed in Boost.Graph section of the Project Ideas page as well as I could provide my own proposals for the library. I would like to get in touch with somebody responsible for Boost.Graph in order to talk about possibilities and what are the priorities. I would be glad to provide this person with additional information. Best, Cezary

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