March 2011 - Boost-users - lists.preview.boost.org

[ASIO] async_accept : Error m_val 1.
by Cyprien DIOT 09 Mar '11

09 Mar '11

Hello, I'm currently developping a tcp server with boost asio with vs2010 on win 7. My server class: Header file: class Server { private: boost::asio::io_service &_io; boost::asio::ip::tcp::acceptor *acceptor; bool connected; boost::asio::ip::tcp::socket *_client; }; Source file: Server::Server(boost::asio::io_service& io) : _io(io) { connected = false; } void Server::receiving() { boost::system::error_code error; acceptor = new tcp::acceptor(_io, tcp::endpoint(tcp::v4(), 14242)); _client = new tcp::socket(_io); connected = false; try { acceptor->async_accept(*_client, boost::bind(&Server::handle_accept, this, boost::asio::placeholders::error)); } catch(...) { } } void Server::handle_accept(const boost::system::error_code& error) { // problem appears here } In main function, i'm running io.run(); I'm using in another class boost asio as a tcp client (which work properly) with the same io_service. When a tcp client connect to boost asio tcp server (Class Server), handle_accept is called. error has the following values: m_val = 1; m_cat = 0x00ab8d00 instance; | [boost::asio::error::detail::misc_category] = {...} | boost::noncopyable_::noncopyable = {...} | __vfptr = 0x00a8bf18 const boost::asio::error::detail::misc_category::`vftable' | [0] = 0x0098aaaa boost::asio::error::detail::misc_category::`scalar deleting destructor'(unsigned int) | [1] = 0x0098b4e1 boost::asio::error::detail::misc_category::name(void) | [2] = 0x0098b603 boost::asio::error::detail::misc_category::message(int) | [3] = 0x0098e39e boost::system::error_category::default_error_condition(int) | [4] = 0x0098bef0 boost::system::error_category::equivalent(class boost::system::error_code const &,int) | [5] = 0x0098cb61 boost::system::error_category::equivalent(int,class boost::system::error_condition const &) Do anyone know what does it mean? Can you help me to fix it? Thank you ! Cyprien DIOT France

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[iostreams] restriction device/filter
by Borko Jandras 09 Mar '11

09 Mar '11

Hello, I'm looking at the implementation of the "restriction" device, from Boost.Iostreams library, which provides access to a subsequence of the original device. When it reaches the end of the input subsequence, the restriction device start performing read()'s of size zero on the original device. Shouldn't it be returning an end-of-sequence marker (EOF) instead? I am using a restriction device as source parameter for the iostreams::copy function and this always results in an infinite loop. Am I doing something wrong? Thanks! - Borko

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[Context] Mac OS X support?
by Nat Linden 09 Mar '11

09 Mar '11

I just glanced over the proposed Boost.Context library documentation prior to a more thorough read, and this TODO item jumped out at me: * support of Mac OS X This is one of our major target platforms. However, it's worth noting that Mac OS X 10.5 introduced support for the ucontext family. We are currently using the (proposed) Boost.Coroutine library [1], [2], a GSoC project from a couple years back. On Windows, Boost.Coroutine uses fibers; on Posix platforms, it uses ucontext. Because Mac OS X 10.4 did not yet support ucontext, I hacked in context-switching for that target based on the Pth library [3]. Boost.Coroutine did not introduce a context-library abstraction layer. Presumably one of the fruits of accepting Boost.Context would be the opportunity to port the Boost.Coroutine API to use Boost.Context rather than its own (similar but not as well-encapsulated) underpinnings. (If anyone cares -- I realize that acceptance of Boost.Fiber could make Boost.Coroutine moot. I intend to read up on that too.) Anyway -- it seems likely to me that Boost.Context will support Mac OS X 10.5+ "out of the box." I intend to check that. If it's important for Boost.Context to support Mac OS X <= 10.4, it might be fairly straightforward to implement the Boost.Context API on top of Pth. Reference [2] contains my macro-based attempt to establish equivalences between the ucontext API and the Pth API. However, at this moment in history, one must ask how important it still is to support Mac OS X <= 10.4? [1] http://www.crystalclearsoftware.com/soc/coroutine/ [2] http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost-… [3] http://www.gnu.org/software/pth/

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[Join] Simplified concept introduction?
by Nat Linden 09 Mar '11

09 Mar '11

I saw the Join library on the review queue and am somewhat curious. But I find the terminology a bit off-putting: ports, chords, joints. I've read the Introduction, the discussion on Join concurrency and the comparison with Futures/Promises. I know this sounds awfully dumb, but I still don't understand the moving parts or how they relate to each other. The Introduction leaves the impression that I could only understand (would only be interested) if I were already a fan of JoCaml or C(omega), neither of which I'd ever heard of before. The library author might reasonably assert that I should read all the available documentation if I want to understand the library. But that's backwards: I have not yet found any reason why I should want to understand this library. When I encounter a new Boost library, my first question is always: how would I use this? What problems in my work would be addressed by this library? How could it make my life easier? The closest I've so far gotten with Join is a vague sense that I could use it to implement Futures, if I didn't already have such a thing. Were I not already somewhat curious about ways to organize async code, I wouldn't have read even this much of the documentation. What's the point of this rant? - I'd like to request a bit more introductory material. If one of the References includes an excellent discussion of why I should be interested, please promote the link (a specific section link) to the Introduction. Otherwise, please add some new prose with specific examples. - I'm aware that this may be clearer to others than it is to me. If you understand the proposed Join library and feel its documentation is sufficient, now would be a good time to say so. My assumption at the moment is that if the Join library were accepted as-is into Boost, few people would even attempt to understand it because, like me, they would have a tough time figuring out how it might apply to their problem space.

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[Review] Phoenix V3: review results
by Hartmut Kaiser 09 Mar '11

09 Mar '11

All, The review of Phoenix V3 ended on March 2nd. We've got quite some discussion, even if we hoped for more. Overall, 3 people have confirmed that the Phoenix rewrite addresses all issues raised during the original review back in 2008. Nobody raised any concerns or serious issues. So here is the result of the mini-review: Boost.Phoenix is ready to be moved to the Boost SVN trunk! All other discussions were about minor inconsistencies, which Thomas has already fixed by now. There are a couple of suggestions related to the documentation, which he agreed to address as soon as possible: 1) The Phoenix documentation should have a "What's New" section 2) Compile time is often a concern with libraries that make heavy use of expression templates. Adding a compile time test would be ideal. This should be easily invoked and results from various compilers reported within the documentation. The only thing, which needs to be decided (and which has not been discussed yet) is how the migration from Boost.Bind, Boost.Lambda, and Phoenix V2 has to be organized, ensuring minimal disruption for the users of those libraries. I see several possible ways of doing so, but would like to open up the discussion. Any suggestions and comments are welcome. With high likelihood this migration process will be implemented using forwarding headers. Therefore, this point has not to be resolved before moving the main code base to trunk. On the other hand, this migration strategy needs to be in place before merging to the release branch. -------------------- This mini-review wraps up the review process of Boost.Phoenix. Congratulations to Thomas for this version of the excellent library, which will contribute to the unification of the functional landscape in Boost. At the same time I would like to mention a couple of names which are related to the development of Phoenix since its inception, and without those Boost.Phoenix wouldn't have happened. - Joel de Guzman, who wrote the initial V1 and since then was actively involved and driving the development of Boost.Phoenix - Dan Marsden, who is the main developer (with Joel) of Phoenix V2 - Angus Leeming and Daniel Wallin who contributed to V2 - Eric Niebler, the author of Boost.Proto, who contributed to V2 and was actively driving and supporting the development of V3, he also mentored Thomas Heller's GSoC project. Regards Hartmut Review Manager --------------- http://boost-spirit.com

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Review Wizard Report for March 2011
by Ronald Garcia 09 Mar '11

09 Mar '11

============================================== Review Wizard Status Report for March 2011 ============================================== News ==== 1. Move Library Accepted 2. Ratio Library Accepted 3. Chrono Library Accepted 4. GIL.IO Library Accepted 5. Boost 1.46 Released New Libraries: Interval Containers Revised Libraries: Array, Asio, Bind, Concepts, Filesystem, Fusion, Graph, Hash, Iterator, Math, Meta State Machine, Optional, Pool, Program Options, Proto, Signals, Spirit, Tokenizer, Unordered, Wave Revised Tools: Boostbook, Inspect, Quickbook Open Issues =========== The following libraries have been reviewed and await reports from their review managers: * Process - reviewed February 2011; review manager: Marshall Clow. * Phoenix - reviewed March 2011; review manager: Hartmut Kaiser. The following libraries have been accepted to Boost, but have not yet been submitted to SVN: * GIL.IO - accepted January 2011; author: Christian Henning. * Move - accepted February 2011; author: Ion Gaztanaga. The following libraries have been accepted and submitted to SVN, but have not yet appeared in a release: * Geometry Library - accepted November 2009; author: Barend Gehreis et al. * Ratio - accepted October 2010; author: Vicente Botet. * GIL.IO - accepted January 2011; author: Christian Henning. * Chrono - accepted January 2011; author: Vicente Botet. The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * Switch - accepted provisionally January 2008; author: Steven Watanabe. * Log - accepted provisionally March 2010; author: Andrey Semashev. General Announcements ===================== As always, we need experienced review managers. The review schedule has grown substantially but we have few volunteers, so manage reviews if possible and if not please make sure to watch the review schedule and participate. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "rxg at cs dot cmu dot edu" and "phillips at mps dot ohio-state dot edu" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report before we do that, please email Ron or John. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Review Schedule =============== * Join (M) * Pimpl (M) * Endian * Conversion (M) * Sorting (M) * AutoBuffer (M) * Convert * Containers * Type Traits Extensions * Lockfree (M) * Fiber (M) * Quaternions, Vectors, Matrices (M) * Locale * Context * Stopwatches * Autoindex * Variadic Macro Data (M) ``(M)`` marks libraries that need review managers. -------------------- Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Pimpl ----- :Author: Vladimir Batov :Review Manager: Needed :Download: | `Boost Vault <http://www.boost-consulting.com/vault/index.php?action=downloadfile&fil…>`__ | http://www.ddj.com/cpp/205918714 (documentation) :Description: The Pimpl idiom is a simple yet robust technique to minimize coupling via the separation of interface and implementation and then implementation hiding. This library provides a convenient yet flexible and generic deployment technique for the Pimpl idiom. It's seemingly complete and broadly applicable, yet minimal, simple and pleasant to use. Endian ------ :Author: Beman Dawes :Review Manager: Joel Falcou :Download: http://svn.boost.org/svn/boost/sandbox/endian/ :Description: Conversion ---------- :Author: Vicente Botet :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=co…>`__ :Description: Generic explicit conversion between unrelated types. Boost.Conversion provides: * a generic ``convert_to`` function which can be specialized by the user to make explicit conversion between unrelated types. * a generic ``assign_to`` function which can be specialized by the user to make explicit assignation between unrelated types. * conversion between ``std::complex`` of explicitly convertible types. * conversion between ``std::pair`` of explicitly convertible types. * conversion between ``boost::optional`` of explicitly convertible types. * conversion between ``boost::rational`` of explicitly convertible types. * conversion between ``boost::interval`` of explicitly convertible types. * conversion between ``boost::chrono::time_point`` and ``boost::ptime``. * conversion between ``boost::chrono::duration`` and ``boost::time_duration``. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=al…>`__ :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 2X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 70% faster than std::sort. string_sort is roughly 2X as fast as std::sort. AutoBuffer ---------- :Author: Thorsten Ottosen :Review Manager: Robert Stewart :Download: http://www.cs.aau.dk/~nesotto/boost/auto_buffer.zip :Description: Boost.AutoBuffer provides a container for efficient dynamic, local buffers. Furthermore, the container may be used as an alternative to std::vector, offering greater flexibility and sometimes better performance. Convert -------------- :Author: Vladimir Batov :Review Manager: Edward Diener :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=bo…>`__ :Description: The Convert library takes the approach of boost::lexical_cast in the area of string-to-type and type-to-string conversions, builds on the past boost::lexical_cast experience and advances that conversion functionality further to additionally provide: * throwing and non-throwing conversion-failure behavior; * support for the default value to be returned when conversion fails; * two types of the conversion-failure check -- basic and better/safe; * formatting support based on the standard I/O Streams and the standard (or user-defined) I/O Stream-based manipulators (like std::hex, std::scientific, etc.); * locale support; * support for boost::range-compliant char and wchar_t-based string containers; * no DefaultConstructibility requirement for the Target type; * consistent framework to uniformly incorporate any type-to-type conversions. It is an essential tool with applications making extensive use of configuration files or having to process/prepare considerable amounts of data in, say, XML, etc. Containers ---------- :Author: Ion Gaztanaga :Review Manager: John Maddock :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=bo…>`__ :Documentation: `Boost Sandbox <http://svn.boost.org/svn/boost/sandbox/move/libs/container/doc/html/index.h…>`__ :Description: Boost.Container library implements several well-known containers, including STL containers. The aim of the library is to offers advanced features not present in standard containers or to offer the latest standard draft features for compilers that comply with C++03. Type Traits Extensions -------------------------- :Author: Frederic Bron :Review Manager: Joel Falcou :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ty…>`__ :Description: The purpose of the addition is to add type traits to detect if types T and U are comparable in the sense of <, <=, >, >=, == or != operators, i.e. if t<u has a sens when t is of type T and u of type U (same for <=, >, >=, ==, !=). The following traits are added: is_equal_to_comparable<T,U> is_greater_comparable<T,U> is_greater_equal_comparable<T,U> is_less_comparable<T,U> is_less_equal_comparable<T,U> is_not_equal_to_comparable<T,U> The names are based on the corresponding names of the standard template library (<functional> header, section 20.3.3 of the standard). The code has the following properties: * returns true if t<u is meaningful and returns a value convertible to bool * returns false if t<u is meaningless. * fails with compile time error if t<u is meaningful and returns void (a possibility to avoid compile time error would be to return true with an operator, trick but this has little sens as returning false would be better) Lockfree ------------------ :Author: Tim Blechmann :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=bo…>`__ :Documentation: http://tim.klingt.org/boost_lockfree/ :Description: Lockfree provides implementations of lock-free data structures. Lock-free data structures can be accessed by multiple threads without the necessity of blocking synchronization primitives such as guards. Lock-free data structures can be used in real-time systems, where blocking algorithms may lead to high worst-case execution times, to avoid priority inversion, or to increase the scalability for multi-processor machines. Lockfree provides: * boost::lockfree::fifo, a lock-free fifo queue * boost::lockfree::stack, a lock-free stack Fiber ----- :Author: Oliver Kowalke :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=bo…>`__ :Description: C++ Library for launching fibers (micro-threads) and synchronizing data between the fibers. Quaternions, Vectors, Matrices ------------------------------ :Author: Emil Dotchevski :Review Manager: Needed :Download: http://www.revergestudios.com/boost-qvm/ :Description: QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Locale ------ :Author: Artyom Beilis :Review Manager: Chad Nelson :Download: https://sourceforge.net/projects/cppcms/files/boost_locale/boost_locale_for… :Description: The Locale library provides powerful tools that extend existing built-in C++ localization facilities in a Unicode-aware way. Context ------- :Author: Oliver Kowalke :Review Manager: Vicente Botet :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=bo…>`__ :Description: Context provides the ability to switch between different user-level context and is intended to be the basis for a higher abstraction like coroutine and fiber. A user-level context represents the current execution state, including all registers and CPU flags, the instruction pointer, the stack pointer. boost::context encapsulates such a user-level context and is able to store/restore its associated user-level context. This allows multiple execution paths running on a single thread using a sort of cooperative scheduling (in contrast a thread is preemptively scheduled) - the running boost::context decides explicitly when its yields to allow another boost::context to run (user-level context switching). A context can only run on a single thread at any point in time but may be migrated between thread. Stopwatches ----------- :Author: Vicente Botet :Review Manager: Anthony Williams :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=st…>`__ :Description: On top of the standard facilities of Boost.Chrono, Stopwatches provides: * Stopwatches: A facility to measure elapsed time with the ability to start, stop, suspend, or resume measurement. * Stopwatch concept * Scoped helper classes allowing to pairwise start/stop operations, suspend/resume and resume/suspend a Stopwatch. * stopwatch, model of Stopwatch capturing elapsed Clock times. * stopwatch_accumulator, model of Stopwatch capturing accumulated elapsed Clock times. * Stopclocks: a complete time reporting package that can be invoked in a single line of code. * stopwatch_reporter, convenient reporting to an output stream (including wide char streams) of the elapsed time of models of Stopwatch results. * stopclock<Clock> shortcut of stopwatch_reporter<stopwatch<Clock>> AutoIndex (Tool) ---------------- :Author: John Maddock :Review Manager: Daniel James :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=au…>`__ :Documentation: `Boost Sandbox <http://svn.boost.org/svn/boost/sandbox/tools/auto_index/doc/html/index.html>`__ :Description: AutoIndex is a tool for taking the grunt work out of indexing a Boostbook/Docbook document (perhaps generated by your Quickbook file mylibrary.qbk, and perhaps using also Doxygen autodoc) that describes C/C++ code. Traditionally, in order to index a Docbook document you would have to manually add a large amount of <indexterm> markup: in fact one <indexterm> for each occurrence of each term to be indexed. Instead AutoIndex will automatically scan one or more C/C++ header files and extract all the function, class, macro and typedef names that are defined by those headers, and then insert the <indexterm>s into the Docbook XML document for you. Variadic Macro Data ------------------- :Author: Edward Diener :Review Manager: Needed :Download: `Boost Sandbox <http://svn.boost.org/svn/boost/sandbox/variadic_macro_data/>`__ :Description: The variadic_macro_data library adds support and functionality for variadic macros to Boost as well as integrating variadic macros with the Boost PP library without changing the latter library in any way. Libraries under development =========================== See http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction for a current listing of libraries under development.

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[xint] Review ending in 2 days
by Vladimir Prus 09 Mar '11

09 Mar '11

Boosters, I just wanted to remind that review of the Boost.XInt library, by Chad Nelson, is about to end at March 11. So, if you plan to submit a review, please do it now. The documentation for the current version is available at: http://www.oakcircle.com/xint_docs/ The source code is available via Subversion at: http://svn.boost.org/svn/boost/sandbox/xint or can be downloaded at: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=xint.z… Here are the important points: 1. All comments are appreciated. Even if you don't have the time for in-depth study of everything, comments on parts of the library are welcome. In particular, if you are already using logging in your applications and have specialized requirements, you might want to directly check how the proposed library handles them. 2. The reviews and all comments should be submitted to the developers list, boost(a)lists.boost.org and the email should have "[xint]" prefix in the subject to make sure it's not missed. The deadline for reviews is 23:59, March 11, PST, or 2:59, March 12, EST, or 7:59 March 12, UK time, 10:59, March 12 MSK 4. The general review checklist is provided below: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Thanks, Volodya -- Vladimir Prus Mentor Graphics +7 (812) 677-68-40

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Thread question.... detecting deadlocks?
by Eric J. Holtman 09 Mar '11

09 Mar '11

I assume I will find the answer to this right after hitting "send", but my googling so far has turned up nothing. Is there a way to turn on deadlock detection in the thread library somehow? I realize it would be slow, and possibly change the behavior of my program so as to give a "false negative", but I'd still like the option. Sigh. (note to self: don't hold locks across a function, unless you know exactly who and what that function will call).

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[Review] Boost.Type Traits Extension by Frederic Bron
by Joel Falcou 09 Mar '11

09 Mar '11

Dear All, According to the Boost Formal Review Schedule [1], fast track review of Frédéric Bron's extensions to the Type Traits Library starts on March 14th and lasts until March 18th, 2011 under my management. [1]http://www.boost.org/community/review_schedule.html =========== What is it? =========== This extension adds 37 new traits corresponding to the following 37 operators: - binary: ==, !=,<,<=,>,>=, , +, -, *, /, %, +=, -=, *=, /=, %=, , &&, ||, ,&, |, ^,<<,>>,&=, |=, ^=,<<=,>>= - prefix: ++, --, +, -, !, ~, * - postfix: ++, -- Each trait can detect if the operator can be used with particular types and if needed, if the return type is convertible to some type. =================== Getting the library =================== The latest version can be downloaded by different ways: - from the vault with unix line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the vault with dos line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the sandbox:http://svn.boost.org/svn/boost/sandbox/type_traits/ The entry point of the documentation is type_traits/libs/type_traits/doc/html/boost_typetraits/category/value_traits/operators.html The library has been tested with: - MSVC 8, 9, 10 on Windows, - g++ 4.4.5 on Linux, - intel 10.0 and 11.1 on Linux. To test the library, the simplest is to untar the headers in your boost include directory. For this, you can download the header part of the extension: - from the vault with unix line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the vault with dos line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t…

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Review Results for Proposed Boost.Process library
by Marshall Clow 08 Mar '11

08 Mar '11

---------------------------- Executive Summary ---------------------------- Boris Schäling's Process library was reviewed from February 7th, 2011 through February 20, 2011. The library sparked a lively debate on the mailing list, and in the end, eight reviews were submitted: - 1 review ACCEPT - 2 reviews CONDITIONALLY ACCEPT - 5 review DO NOT ACCEPT Since there was not a clear view in either the discussion or the votes that this library should be accepted: The Process library IS NOT ACCEPTED into Boost. There was considerable disagreement both about the scope of the library (what features to provide) and how the features were implemented. More than one alternate design was proposed, and the advantages and disadvantages of various approaches (where to install signal handlers, having a single thread vs. one thread/child) were debated vigorously. However, there was a fairly broad consensus that the library, in its present state, was not ready to be included into Boost. Thank you to everyone who participated, and especially to Boris and those who wrote a review. I would like to encourage Boris to continue development of his library and to resubmit it for review at a future date. ---------------------------- Concerns voiced by reviewers (a partial list) ---------------------------- * There was considerable push back by the reviewers about the cross-platform interface; specifically the use of #ifdefs * Artyom pointed out the possibility of deadlock given the current implementation, and a lack of wide-character support on Windows. * Oliver said "I'm missing the possibility to send signals to a process and to wait for a process to be stopped (SIGSTOP) or resumed (SIGCONT) using boost.asio." * There was a lot of discussion about the correct way to handle SIGCHILD, and how to implement passing data back and forth between the parent and child processes. * There was an involved many-sided discussion on about what facilities a Boost.Process library should provide. * More than one person proposed an alternate interface for the library (Jeff Flinn, Darren Garvey, Max Sobolev, possibly more) * Brendon Costa expressed concerns that it would be easy to end up with zombie processes using the current library. * Jeremy Maitin-Shepard felt that "The lack of efficient asynchronous waiting support, and the overly complicated stream behavior interface, are show-stoppers for me". * Jeff Flinn did not like the lack of launch error reporting (among other things) -- Marshall Clow; Review Manager

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[graph] Is reverse_graph<> read-only?
by al.zatv 08 Mar '11

08 Mar '11

Hello! Is reverse_graph<> in Boost::Graph Library, read-only? I just can't beleive it:) Can it be fixed?

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FW: compiling parallel boost graph lib
by Xin Sui 08 Mar '11

08 Mar '11

Hi: When I compile parallel boost graph library, I encounter the following errors: parallel-bgl-0.7.0/boost/graph/distributed/adjlist/serialization.hpp: In function `std::vector<int, std::allocator<int> > boost::detail::parallel::available_process_files(const std::string&)': parallel-bgl-0.7.0/boost/graph/distributed/adjlist/serialization.hpp:97: error: conversion from `boost::filesystem3::path' to non-scalar type `std::basic_string<char, std::char_traits<char>, std::allocator<char> >' requested make[2]: *** [libs/graph_parallel/test/CMakeFiles/adjlist_build_test.dir/adjlist_build_test.cpp.o] Error 1 make[1]: *** [libs/graph_parallel/test/CMakeFiles/adjlist_build_test.dir/all] Error 2 The CMake found the following software: gcc (GCC) 3.4.6, Boost version: 1.46.0 and openmpi 1.3, c++ (GCC) 3.4.6 20060404 (Red Hat 3.4.6-11) Do you guys have an idea what the problem is? Thanks Xin

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Boost Interprocess error on Solaris sun studio 12
by aidan mcgurn 08 Mar '11

08 Mar '11

Hi, Currently my company are having issues compiling Boost Interprocess 1.42 on Solaris sun Studio. I see from Boost documentation that this compiler is not listed as having been used to build Interprocess: i.e. * Visual 7.1 Windows XP * Visual 8.0 Windows XP * GCC 4.1.1 MinGW * GCC 3.4.4 Cygwin * Intel 9.1 Windows XP * GCC 4.1.2 Linux * GCC 3.4.3 Solaris 11 * GCC 4.0 MacOs 10.4.1 I have also seen from this next thread that there is a bug logged against this issue as posted from someone with a similar issue: http://forums.oracle.com/forums/thread.jspa?threadID=1992480&tstart=45 "Unfortunately, your problem is one of the outstanding issues with Boost that we have not yet resolved. This one is bug number 6954828, generated internally, and not visible at bugs.sun.com. Fixing bugs that prevent Boost from compiling is a priority item for us, but I can't predict when a fix for this problem will be available." This was posted a year ago so i am wondering has this been fixed in recent Boost editions or plans to? If not is there a recommended workaround? (outside the posts suggested flag changes "-D_POSIX_C_SOURCE=4 -D_XPG4 -D_XPG4_2" which are unpredictable to other parts of our system) thanks for any suggestions, /aidan ======= Errors i see: "/spare/integra/thirdparty/include/boost/interprocess/mapped_region.hpp", line 549: Error: Formal argument 1 of type char* in call to shmdt(char*) is being passed void*. "/spare/integra/thirdparty/include/boost/interprocess/shared_memory_object.hpp", line 284: Error: The function "shm_open" must have a prototype. "/spare/integra/thirdparty/include/boost/interprocess/shared_memory_object.hpp", line 307: Error: The function "shm_unlink" must have a prototype.

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[Regex] Search Substring
by S Nagre 08 Mar '11

08 Mar '11

Hi, I am new to boost Libraries and I am trying to find a substring using Boost::Regex Lets say I want to find string "Hello" in "Hello world". std::string completeStr = "Hello World"; std::string::const_iterator startOffset = completeStr.begin(); std::string::const_iterator endOffset = completeStr.end(); std::string searchWord= "Hello"; boost::regex expression(searchWord); boost::match_flag_type flags = boost::match_any; while(boost::regex_search(startOffset, endOffset, what, expression, flags)) { int32 position = what.position(1); int32 len = what[1].length(); } but value of this position and length value is coming out to be -1. It is not able to find this substring, Could anyone tell me what I am doing wrong ? Subhash

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multi_index_container insert is excruciatingly slow
by Georges Dupret 08 Mar '11

08 Mar '11

Hi! In spite of compiling with NDEBUG set: g++ -Wall -D_REENTRANT -msse2 -mfpmath=sse -Wno-deprecated -DNDEBUG -c -O3 -I/home/gdupret/.local/lib64/include/ -MMD -MP -MF build/Release/GNU-Linux-x86/Model.o.d -o build/Release/GNU-Linux-x86/Model.o Model.cpp, inserting into a multi_index_container is excruciatingly slow. I have a large nbr. of elements to insert (10^5) but even the first 1000 are very slow. I also set: #ifndef NDEBUG #define NDEBUG #endif #ifdef BOOST_MULTI_INDEX_ENABLE_INVARIANT_CHECKING #undef BOOST_MULTI_INDEX_ENABLE_INVARIANT_CHECKING #endif #ifdef BOOST_MULTI_INDEX_ENABLE_SAFE_MODE #undef BOOST_MULTI_INDEX_ENABLE_SAFE_MODE #endif in the header calling the multi_index_container, but I see no change. Any suggestion on how I should do? Best ge

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[uBLAS] Results of different size matrix addition
by Ryan 08 Mar '11

08 Mar '11

According to the preconditions for binary matrix operations both matrix must have the same size ( http://www.boost.org/doc/libs/1_46_0/libs/numeric/ublas/doc/matrix_expressi…) What runtime error should I expected if the matrix sizes are not the same? Ryan

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[ICL] More compilation questions/problems
by John Reid 08 Mar '11

08 Mar '11

#include <boost/icl/interval.hpp> template< typename IntervalT > void check_contains() { IntervalT interval; typedef typename IntervalT::domain_type domain_t; ::boost::icl::contains( interval, domain_t() ); } void h() { namespace icl = ::boost::icl; check_contains< icl::continuous_interval< float > >(); check_contains< icl::discrete_interval< int > >(); check_contains< icl::right_open_interval< float > >(); check_contains< icl::left_open_interval< float > >(); check_contains< icl::closed_interval< float > >(); check_contains< icl::open_interval< float > >(); } The last 2 lines in h() do not compile whilst the preceeding 4 do. Is this by design or a bug? Testing elements for membership of a closed or open interval seems natural enough. I'm using gcc 4.4.3. Thanks, John.

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[general] is there a noop deallocator in boost?
by Mostafa 07 Mar '11

07 Mar '11

Hi all, I'm interested in a noop deallocator for use in shared_ptr, but can't find one in boost, so does anyone know of one? (I know it's trivial to write one, but that doesn't out weight the convenience of using a standardized one.) Thanks, Mostafa

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[ptr_container] compiler error with BOOST_RESULT_OF_USE_DECLTYPE
by Nathan Ridge 07 Mar '11

07 Mar '11

Hello, The following code: #include <boost/ptr_container/ptr_set.hpp> struct A { bool operator<(const A&) const; }; int main() { boost::ptr_set<A> s; return 0; } gives the following compiler errors when compiling with BOOST_RESULT_OF_USE_DECLTYPE defined: In file included from ../../lib/boost- 1.45/boost/preprocessor/iteration/detail/iter/forward1.hpp:52:0, from ../../lib/boost-1.45/boost/utility/result_of.hpp:92, from ../../lib/boost-1.45/boost/ptr_container/indirect_fun.hpp:23, from ../../lib/boost-1.45/boost/ptr_container/ptr_set.hpp:19, from test.cpp:1: ../../lib/boost-1.45/boost/utility/detail/result_of_iterate.hpp: In instantiation of 'boost::detail::cpp0x_result_of_impl<less<A>(A &)>': ../../lib/boost-1.45/boost/utility/detail/result_of_iterate.hpp:44:8: instantiated from 'boost::result_of<less<A>(A &)>' ../../lib/boost-1.45/boost/ptr_container/indirect_fun.hpp:107:9: instantiated from 'boost::void_ptr_indirect_fun<less<A>, A, A>' stl_tree.h:462:31: instantiated from '_Rb_tree< void *, void *, _Identity<void *> , boost::void_ptr_indirect_fun<less<A>, A, A> >' stl_set.h:112:17: instantiated from 'set< void *, boost::void_ptr_indirect_fun<less<A>, A, A> >' ../../lib/boost-1.45/boost/ptr_container/ptr_set_adapter.hpp:40:21: instantiated from 'boost::ptr_container_detail::set_config< A, set<void *, boost::void_ptr_indirect_fun<less<A>, A, A> >, true >' ../../lib/boost-1.45/boost/ptr_container/detail/reversible_ptr_container.hpp:87:59: instantiated from 'boost::ptr_container_detail::reversible_ptr_container< boost::ptr_container_detail::set_config< A, set<void *, boost::void_ptr_indirect_fun<less<A>, A, A> >, true >, boost::heap_clone_allocator >' ../../lib/boost-1.45/boost/ptr_container/detail/associative_ptr_container.hpp:32:11: instantiated from 'boost::ptr_container_detail::associative_ptr_container< boost::ptr_container_detail::set_config< A, set<void *, boost::void_ptr_indirect_fun<less<A>, A, A> >, true >, boost::heap_clone_allocator >' ../../lib/boost-1.45/boost/ptr_container/ptr_set_adapter.hpp:122:11: instantiated from 'boost::ptr_container_detail::ptr_set_adapter_base< A, set<void *, boost::void_ptr_indirect_fun<less<A>, A, A> > , boost::heap_clone_allocator, true >' ../../lib/boost-1.45/boost/ptr_container/ptr_set_adapter.hpp:299:11: instantiated from 'boost::ptr_set_adapter< A, set<void *, boost::void_ptr_indirect_fun<less<A>, A, A> > , boost::heap_clone_allocator, true >' ../../lib/boost-1.45/boost/ptr_container/ptr_set.hpp:33:11: instantiated from 'boost::ptr_set<A>' ../shared/test/test.cpp:10:23: instantiated from here ../../lib/boost-1.45/boost/utility/detail/result_of_iterate.hpp:70:69: error: no match for call to '(less<A>) (A &)' stl_function.h:230:12: candidate is: stl_function.h:233:7: bool less<A>::operator()(const A &, const A &) const stl_function.h:233:7: candidate expects 2 arguments, 1 provided I am compiling with g++ 4.5 with the --std=c++0x flag. The error goes away if I do not define BOOST_RESULT_OF_USE_DECLTYPE (but I need this define for other things). Am I doing something wrong or is this a bug? Thanks, Nate.

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spirit classic - matching end of file space
by Noah Roberts 07 Mar '11

07 Mar '11

I have a parser that works great except if there's space at the end of the stream. I can't seem to come up with a manner to match that space. The file consists of a header block followed by any number of "shape" blocks. I'm calling the parser with: boost::spirit::classic::parse(begin, end, grammar, boost::spirit::classic::space_p) My file grammar looks like so: shape_file = !( header[assign_a(self.header_was_read, t)][assign_a (self.read_header, shape_file_header_grammar::current_header)] ) >> *( shape[push_back_a(self.read_shapes, shape_grammar::current_shape)] ) ; The parser seems to break down because space at the end of the stream makes it try to read another shape. My shape grammar looks like so: shape_block = // := <shape_header> "Begin" <element>* "End" (shape_header | shapeheader_error) >> (as_lower_d["begin"] | begin_error) >> *element >> as_lower_d["end"] ; I've tried adding '*space_p' at the end of both of the above. I've also tried '*lexeme_p[space_p]' in both. Neither fixes the problem. I've left out the various other bits of the grammars because it all works, with this minor issue about end of file space. I'm hoping that it's irrelevant to the problem. How might I go about gobbling up any end-of-file spaces in this setup? -- http://crazycpp.wordpress.com/

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[GIL] write gray32fc_view_t to PNG
by Alex Flint 07 Mar '11

07 Mar '11

Hi there, I'm trying to write a grayscale image of 32-bit floats to a file. I understand that I need to construct some kind of color converted view but I can't find much documentation on this. So far I have gray32fc_view_t view = ....; png_write_view(file, view); Which gives me a static assertion failure (I suppose png_write_view can't handle 32-bit float views directly). Cheers, Alex

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GUI creation for boost::graph
by Bastien ROUCARIES 07 Mar '11

07 Mar '11

Hi, I whish to create a boost graph gui using qt However I have a problem I do not know how to link qt to boost graph. If I use bundle property of qt object could I get next and previous node from the qtobject? I am thinking about using a sets indexed by qtobject adress but I seems really painfull for managing memory. Particularly I want my implement my algorigthm on the graph and able to modify the graphical object from the boost::graph but also able to modify the graph from graphical qt object Any ideas? Bastien

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[gil] inverting alpha channel
by Alex Flint 07 Mar '11

07 Mar '11

Hi there, I have RGBA images using alpha=0 as opaque and alpha=255 as transparent. Is there any way that I can get png_write_view to use this convention without actually changing the data? Cheers, Alex

2 1

[GIL] IO Errors
by Szymon Gatner 07 Mar '11

07 Mar '11

Hi, Why calls like png_read_image that take actual filename to load do not throw an exception that carries that filename? cheers, Szymon

2 1

[BGL] depth first search : forcing backtrack
by andreas tanner 07 Mar '11

07 Mar '11

I understand that for early exit from a depth_first_search, I use exceptions thrown in a visitor. Now how can I force not a complete exit, but just an immediate backtrack towards the root node?

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