March 2011 - Boost - lists.boost.org

[type_traits] extension has_operator_xxx - cv qualifiers and references
by Frédéric Bron 06 Mar '11

06 Mar '11

New version of the type_traits extension available here: - vault unix newlines: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - vault dos newlines: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - sandbox: http://svn.boost.org/svn/boost/sandbox/type_traits/ This version now handles correctly cv qualifiers and references, which was not the case before. Frédéric

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[xint] Performance of fixed-size large integers
by Phil Endecott 06 Mar '11

06 Mar '11

Dear All, I've never needed to use arbitrary-precision integers, but I have sometimes wanted large fixed-size integers like uint128_t, and so I've had a quick look at that aspect of the proposed Xint. The docs' front page has a link under "Detailed Usage Information" to "Fixed-Length Integers" - which is not really very detailed, and has examples in the notes like "integer_t<8>" that don't work. I established quickly enough that the correct syntax is integer_t<fixedlength<8>>. Also I noted that the conventions here don't match the built-in (u)intN_t types, i.e. int64_t vs. int63_t and the "wrap-around" behaviour. Perhaps there is some rationale for this, but I would be happier to see it consistent with the built-in types. (It might also be appropriate to think about how this could work with the existing Boost.Integer.) I have done a quick test of the performance of a 96-bit type as follows: typedef boost::xint::integer_t< boost::xint::options::fixedlength<96> > uint96_t; uint96_t a = 0; uint96_t b = 0; for (int i=1; i<loops; ++i) { a = a + a + (a & b) + i; b = b + i; } This is an entirely contrived example, but the point is to minimise the work that I have to do to create something to compare it with; by using only operator+ and operator&, I can quickly hack together this: struct uint96_t { uint32_t top; uint32_t mid; uint32_t bottom; uint96_t() {} uint96_t(uint32_t val): top(0), mid(0), bottom(val) {} }; uint96_t operator&(uint96_t a, uint96_t b) { uint96_t r; r.top = a.top & b.top; r.mid = a.mid & b.mid; r.bottom = a.bottom & b.bottom; return r; } uint96_t operator+(uint96_t a, uint96_t b) { uint96_t r; __asm__( "adds %0, %3, %6\n" // Add and set carry flag "adcs %1, %4, %7\n" // Add with carry-in and set carry flag "adc %2, %5, %8\n" // Add with carry-in. : "=r" (r.bottom), // %0 "=r" (r.mid), // %1 "=r" (r.top) // %2 : "r" (a.bottom), // %3 "r" (a.mid), // %4 "r" (a.top), // %5 "r" (b.bottom), // %6 "r" (b.mid), // %7 "r" (b.top) // %8 : "cc" ); return r; } It seems to me that that is several hundred times faster than the Xint code (on my 1.2 GHz ARM test system). Yes, it requires assembler in order to do multi-word addition with carry, but we can write a less efficient portable version of that: uint96_t operator+(uint96_t a, uint96_t b) { uint96_t r; r.bottom = a.bottom + b.bottom; int carry0 = r.bottom < a.bottom ? 1 : 0; r.mid = a.mid + b.mid + carry0; int carry1 = r.mid < a.mid ? 1 : 0; // hmm, not totally sure about that... r.top = a.top + b.top + carry1; return r; } This is about half the speed of the assembler, but still hundreds of times faster than the Xint code. Based on that, I think the claim that the library is "fast" on its front page needs substantiating. I encourage anyone with experience of arbitrary-precision variable-length numbers to run some quick benchmarks. (Or, maybe I'm doing something horribly wrong here. I haven't even checked that I get the right answer.) Other reviews have reported that in this fixed-length case the library still stores some overhead in addition to the actual data. That's unfortunate as I would like to be able to, for example, store values in a memory-mapped file, or to use them in e.g. Beman's proposed b-tree library. I don't want to write a review that says "This library doesn't do what I want, therefore it should be rejected". No doubt others will find applications where it will be useful. But I think the performance when used for fixed-size integers should be investigated. Regards, Phil.

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[xint] Review
by Mathias Gaunard 05 Mar '11

05 Mar '11

I would like to vote against acceptance of the XInt library in Boost. The various comments I have written in other threads should be enough to justify that vote.

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[Locale] Version 2.93 released
by Artyom 05 Mar '11

05 Mar '11

Hello All, New version 2.93 of Boost.Locale was released: ============================================== Documentation: http://cppcms.sourceforge.net/boost_locale/html/index.html Downloads: https://sourceforge.net/projects/cppcms/files/boost_locale/ What is Boost.Locale ==================== Boost.Locale is a library that provides high quality localization facilities in a C++ way. It uses std::locale facets to provide localization in transparent and C++-aware manner. Changes in this version ======================== Breaking changes: ----------------- - The default locale's narrow encoding under Microsoft Windows is now UTF-8. It can be reverted back to ANSI encoding by using boost::locale::generator::use_ansi_encoding() for compatibility with legacy applications - The default encoding of "add_messages_path" (location of message catalogs) on Windows is now locale's encoding. Removed wide path API as inconsistent and too Windows specific. New Features: ------------- - Added date_time and calendar support for non-ICU based backends. It is limited to the Gregorian calendar only but fully supports local start of week and OS specific local time handling. Enhancements: ------------- - Major performance optimizations for ICU backend. It uses TLS for caching of collation and formatting objects. Boost.Thread is now required dependency when using ICU or using Boost < 1.43 - Performance optimizations for std collation backend - Added support of checking if current time is in daylight savings time - Tutorial is converted to Doxygen format and now much easier to navigate. - Language corrections of the tutorial by Chad Nelson. Thanks! - Workaround of ICU bug in detection of the OS timezone on Linux for ICU versions 4.0-4.4 - Numerous bug fixes. TODO: ----- Currently Boost.Build is not supported only CMake is valid build option. It would be fixed in next release before the formal review. Regards, Artyom Beilis. ----------------------------------------------------------------- My other projects: CppCMS - C++ Web framework: http://cppcms.sourceforge.net/wikipp/en/page/main CppDB - C++ SQL Connectivity Library: http://cppcms.sourceforge.net/sql/cppdb/

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SVN slow again?
by John Maddock 05 Mar '11

05 Mar '11

I've been trying and failing to check out a copy of the release branch the last two days - I keep getting SVN timeouts. Looking at svn.boost.org I see the server load has gone up to 23.92 which seems crazy high compared to where it was before? Any ideas? Thanks, John.

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Knapsack problem
by Dávid Tóth 05 Mar '11

05 Mar '11

Would it be useful to have a library that would be able solve Knapsack problem?

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[DynamicAny] Feedback
by Daniel Larimer 05 Mar '11

05 Mar '11

I recently ran into a problem where I wanted to retrieve the value stored in a boost::any by casting to a base class. Unfortunately, boost::any requires you cast out the exact type as that held. Boost.DynamicAny is a vairant on Boost.Any which provides more flexible dynamic casting of the underlying type. Whereas retreiving a value from Boost.Any requires that you know the exact type stored within the Any, Boost.DynamicAny allows you to dynamically cast to either a base or derived class of the held type. Boost.DynamicAny passes all of the same unit tests as Boost.Any, but additionally supports the following test: #include <boost/dynamic_any.hpp> using boost::dynamic_any_cast; struct base { int a; }; struct base1 { int a1; }; struct derived : base, base1 { int b; }; struct other {}; void test_dynamic_cast() { derived d; dynamic_any a(d); derived & ra = dynamic_any_cast<derived&>(a); base & b = dynamic_any_cast<base&>(a); base1 & b1 = dynamic_any_cast<base1&>(a); const base1 & cb1 = dynamic_any_cast<const base1&>(a); TEST_CHECK_THROW( dynamic_any_cast<other&>(a), bad_dynamic_any_cast, "dynamic_any_cast to incorrect reference type"); For scalar types, Boost.DynamicAny works just like Boost.Any. This means that it currently does not support dynamic casting of pointers stored within the any, but that should not be too hard to add. https://github.com/bytemaster/Boost.DynamicAny

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[PATCH v2] [exception] Replace C cast with static_cast for Metrowerks C++
by Joshua Juran 05 Mar '11

05 Mar '11

Metrowerks C++ 2.4.1 thinks the type of (T*)0 is T, rather than T*. But static_cast works fine. --- This patch doesn't affect the compilation of g++ 4.0.1. diff --git boost/exception/exception.hpp boost/exception/exception.hpp index adaac68..afb2008 100644 --- boost/exception/exception.hpp +++ boost/exception/exception.hpp @@ -334,7 +334,7 @@ boost struct enable_error_info_return_type { - typedef typename enable_error_info_helper <T,sizeof(exception_detail::dispatch_boost_exception((T*)0))>::type type; + typedef typename enable_error_info_helper < T ,sizeof (exception_detail ::dispatch_boost_exception(static_cast<T*>(0)))>::type type; }; }

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[PATCH] [exception] Replace C cast with reinterpret_cast for Metrowerks C++
by Joshua Juran 05 Mar '11

05 Mar '11

Metrowerks C++ 2.4.1 thinks the type of (T*)0 is T, rather than T*. But reinterpret_cast works fine. --- This patch doesn't affect the compilation of g++ 4.0.1. diff --git boost/exception/exception.hpp boost/exception/exception.hpp index fd516dd..87063af 100644 --- boost/exception/exception.hpp +++ boost/exception/exception.hpp @@ -334,7 +334,7 @@ boost struct enable_error_info_return_type { - typedef typename enable_error_info_helper <T,sizeof(exception_detail::dispatch_boost_exception((T*)0))>::type type; + typedef typename enable_error_info_helper < T ,sizeof (exception_detail ::dispatch_boost_exception(reinterpret_cast<T*>(0)))>::type type; }; }

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[chrono] [thread] Incorporating Chrono into Boost.Thread implementation
by David Deakins 05 Mar '11

05 Mar '11

During the review of the Boost.Chrono library and earlier, there was some discussion about how Boost.Thread might adopt the Chrono-based interfaces once Chrono was formally accepted and merged into the trunk. I believe that Vicente even had proposed code for some of the possible changes. Now that Ratio and Chrono are officially part of Boost, is there still an intention to do this? If so, is there any timeline for when these Boost.Thread changes might begin appearing in the trunk? I know this depends on Anthony and others' availability, but I was just curious. Thanks, -Dave

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[general] mingw.org site was hacked
by Jim Bell 04 Mar '11

04 Mar '11

Of interest to MinGW users: It seems that the mingw.org site was hacked a couple days ago: <http://sourceforge.net/mailarchive/message.php?msg_id=27147169>

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Review Wizard Report for March 2011
by Ronald Garcia 04 Mar '11

04 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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[ASIO] async_accept : Error m_val 1.
by Cyprien DIOT 04 Mar '11

04 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(); Moreover, 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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[date_time] Concurrent posix_time streaming crashes under MinGW-32
by Jim Bell 04 Mar '11

04 Mar '11

The attached program crashes under MinGW-32 (gcc-4.4), but works under VC8. It does concurrent streaming of posix_time::ptime values to independent std::ostringstream's. Mutexing the ostringstream from construction to destruction keeps it from crashing, but that shouldn't have to be done for independent streams. Mutexing just the ptime insertions makes it run longer, but it still crashes. I made it a Trac ticket, but wondered if anyone here had any input on it. Could it be a GCC or MinGW bug? Are other platforms escaping a crash just by luck? Building: MinGW: g++ -DBOOST_THREAD_USE_LIB DTConcur.cpp -IC:\Software\Open\lib\boost_1_45_0\ -DWIN32 -D_WINDOWS -LC:\Software\Open\lib\boost_1_45_0\mgw44\lib -mthreads -g -frtti -fexceptions -mthreads -Wall -lstdc++ -lmingw32 -o DTConcur -lboost_thread-mgw44-mt-s-1_45 VC8: cl DTConcur.cpp /IC:\Software\Open\lib\boost_1_45_0\ /MT /D BOOST_THREAD_USE_LIB /GR /EHsc /D "WIN32" /D "_WINDOWS" /FeDTConcur.exe /link /LIBPATH:C:\Software\Open\lib\boost_1_45_0\msvc8\lib

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[phoenix 3] Review
by Michael Caisse 04 Mar '11

04 Mar '11

I have been anticipating this mini-review since the Phoenix V2 review results were first announced. I am a heavy user of Phoenix and am excited to see it take it's place as a first class citizen. Thomas has done an excellent job at surpassing the requirements for the review and making Phoenix an extensible FP tool. Executive Summary: Phoenix 3 has meet the requirements and should be moved to the trunk for integration. ----- The initial review concluded with the following main points needing to be addressed in the mini-review. - the breaking interface changes from v2 - the migration path from boost::bind and lambda to Phoenix - how the interoperability with std::bind is solved (result_of semantics) - C++0x features such as rvalue references and variadic templates - the new extensibility mechanism - unified placeholders and interoperability issues with other Proto-based DSELs (such as Spirit.Qi, Spirit.Karma, and Xpressive) - compile times Thomas has addressed all of the above points; however, I would like to see two of them "documented" differently. o The Phoenix documentation should have a "What's New" section such as Spirit does. It can tersely represent the improvements, changes and most of all breaking-changes. o Compile time is often a concern with libraries that make heavy use of expression templates. While I personal don't care much about the subject, I also don't see an objective way to determine if it is better or worse with subsequent releases. Adding a compile time test would be ideal. This should be easily invoked and results from various compilers reported within the documentation. ----- Not on the list of items to review: o At some point there should be a runtime benchmark added. o Minor doc diffs attached o function.qbk : factorial.cpp is missing o BOOST_PHOENIX_DEFINE_EXPRESSION_EXT_VARARG bottom of page has TBD for the Example Thank you Thomas and the Phoenix team for such a wonderful library! michael -- Michael Caisse Object Modeling Designs www.objectmodelingdesigns.com

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detect an enum type in template arguments
by Aston 03 Mar '11

03 Mar '11

Hi, consider the example below, is there a way to detect an enum type and non-enum type ? thus if there were a way to do it, assume it to be "is_enum<T>::value" then the output of example below would have been output: Generic Type Enumeration Type **************************** example begins *************************** // all types except enumeration come here template T> class Foo { void identify() { std::cout << "Generic"; } }; // all enumerations types come here <template T> class Foo<is_enum<T>::value> { void identify() { std::cout << "Enumeration"; } }; enum BarEnum { Mon, Tue, Wed }; int main( int argc, char* argv[]) { std::cout << Foo<int> << " Type" << std::endl; std::cout << Foo<BarEnum> << " Type" << std::endl; return 0; } **************************** example ends *************************** Aston

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[1.46.1] branches/release open for bug fixes only
by Beman Dawes 03 Mar '11

03 Mar '11

We are going to do a point release next week. branches/release is now open for merging bug fixes only, including documentation fixes. As always, please make sure the fix is stable on trunk before merging to release. The cutoff for merging is noon Eastern US time on Tuesday, March 8th. We have to hold to a tight schedule because of other commitments later in the month. --Beman

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New meta-multiprecision library of interest.
by Topher Cooper 03 Mar '11

03 Mar '11

The following will be of interest to the numericists among us: Christopher Kormanyos. 2011. Algorithm 910: A Portable C++ Multiple-Precision System for Special-Function Calculations. ACM Trans. Math. Softw. 37, 4, Article 45 (February 2011), 27 pages. DOI=10.1145/1916461.1916469 http://doi.acm.org/10.1145/1916461.1916469 The abstract: This article presents a portable C++ system for multiple precision calculations of special functions called e_float. It has an extendable architecture with a uniform C++ layer which can be used with any suitably prepared MP type. The system implements many high-precision special functions and extends some of these to very large parameter ranges. It supports calculations with 30 ... 300 decimal digits of precision. Interoperabilities with Microsoft’s® CLR, Python, and Mathematica® are supported. The e_float system and its usage are described in detail. Implementation notes, testing results, and performance measurements are provided. I only just saw this, and skimmed the article but, based on that skimming (and subject to possible misunderstandings) it is worth noting: A key part of the package not fully captured in the abstract is that it provides a uniform C++ interface for MP packages. For the purposes of that uniform interface its special functions includes a pretty good set of not-so-special functions like addition, integer part, etc. It includes its own MP package designed for portability. There are a lot of functions (inevitably) not covered. I noticed the total absence of specifically statistical distribution functions -- not even the error function seems to be included. The author claims to welcome others to extend the package, however. The Python interoperability is provided via Boost.Python so the author has some awareness of Boost. To me this library seems very Boostish, some Booster deeper in the numerical library field might wish to investigate how hard it would be to Boostify this and whether the author is interested. The ACM, which holds the copyright on this paper, allows copies to be made for "personal use." I think that sharing a copy with anyone with a reasonably serious non-comercial interest who doesn't otherwise have access falls within this permission, so if you need a copy of the paper let me know via my first name on my net domain at company topherc. Topher

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[xint] Review
by Christian Henning 03 Mar '11

03 Mar '11

Hi there, first I like to congratulate Chad for his very valuable contribution to the boost community. > 3. Please explicitly state in your review whether the library should be accepted. YES! > > 4. The general review checklist is provided below: > > - What is your evaluation of the design? Looks very thought out to me. No complains. > - What is your evaluation of the implementation? I find the code pretty hard to read. Is it true that the code is cut to 80 characters a line? I'm not sure if that's a good decision. There are plenty of warnings when warning level is set to 4 on VS2010. Most of them are "warning C4127: conditional expression is constant" which seems to me that they could be removed by using compile time polymorphism. > - What is your evaluation of the documentation? Looks very nice. Just one thing. Where can I find a list of preprocessor symbols that are used during the compilation process. For instance, I like to know more about BOOST_XINT_MOVE. The rsa example is missing the "iterator" header. > - What is your evaluation of the potential usefulness of the library? If someone needs a bigint lib he/she should look no further. Would be interesting to see how well this lib compares to similar C libs in terms of performance and functionality. > - Did you try to use the library? With what compiler? Did you have any > problems? I used it with VS2010 in 64bit configuration. > - How much effort did you put into your evaluation? A glance? A quick > reading? In-depth study? A glance with some example code testing. > - Are you knowledgeable about the problem domain? Not really. Regards, Christian

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[1.46.1] Should we try for a point release?
by Beman Dawes 03 Mar '11

03 Mar '11

>From my viewpoint, the process of putting together a release is now smooth enough that I'm willing to do a point release, but... (1) Do we have enough fixes that will be ready by, say, a week from today to make a point release worthwhile? (2) We would need to be sure that we have a procedure that ensures that fixes for the point release don't get dropped from the next full release. (3) The C++ committee meets March 21-26 in Madrid. That means there's about three weeks, say March 14 - April 3, where those of us, including me, going to that meeting will be too tied up for Boost work. That why (1) says "a week from today". --Beman

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Re: [boost] [xint] Boost.XInt formal review
by Jarrad Waterloo 03 Mar '11

03 Mar '11

This library is useful as is but I would suggest a few additional features for convenience especially among the most common use cases. 1) convenience functions preferably, documented example is acceptable, for extracting a integer, int, long int ... starting at a particular unsigned bit offset for a particular length 2) convenience functions preferably, documented example is acceptable, for creating a mask starting at a particular unsigned bit offset for a particular length 3) examples of using this if possible with boost::date in order to efficient work with dates outside the existing limits 4) conversion to and from dynamic_bitset [already suggested just seconding] 5) conversion to and from bitset For all those other reviewers who may complain about performance when comparing with GMP, please bear in mind that large numbers are useful to domains other than security were assembly level performance is nice but doesn't outweigh other concerns such as portability and ease of use. This library and others much needed even overdue for the C++ non C community.

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Phoenix 3 Review
by Joel Falcou 03 Mar '11

03 Mar '11

So here is my short review on phoenix 3. I wont comment on the quality of the code and the implementation as I followed Thomas durign his GSoC. On an user perspective, i'll place myself on the "advacned user" plate. i see Phoenix as a great to enable lazy evalaution in a large number of situation. its integration in proto is now making it a nice boilerplate code for more advanced libraries. I've played with test adn examples and found them to be good. My overall opinion is that YES, this version of Phoenix fulfills the requirements of th eprevious review adn thomas addressed them in quite an efficient way. Now, as an advanced nitpicker ;) i have a small set of request: - the doc need more examples of proto interoperability either in use cases or in various extension points. IIRC there was sone phoenix-> C cod ein a string example that was never finished, it coudl be good if this could be fleshed out. multistage programming is a Nice technique that need promotion and exposure. Phoenix seems to be perfect for that. - Could the various compile time / runtime performances tests be itnegrated in the doc if they are a/ done and b/ give some insight. If needed i can run some on non-trivial architecture/compiler and report results So, I very welcome the addition of Phoenix 3 as a full citizen of boost.

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1.46 problems
by Nikolay Mladenov 03 Mar '11

03 Mar '11

I am resending this since I accidentally sent an unfinished email. I recently upgraded from 1.43 to 1.46 and this broke our serialization. We could not read archives saved with 1.43. I the investigation I noticed the following issues. 1. in basic_binary_iarchive tracking_type is loaded as integer type or bool, but in basic_binary_oarchive it is stored as primitive type tracking_type. This breaks custom binary archives that have overloads for integer types and bool. this problem probably applies to other internal serialization types (collection_size_type, version_type, etc), but I have not investigated this. 2. We use custom binary archives which have overloads for integer types (loosely) like that: class custom_binary_iarchive : boost::archive::binary_iarchive_impl<custom_binary_iarchive> { public: void load(integral_type &t){...} void load(non_integral_type &t){...} }; When loading std::vector from archive stored with 1.43 the following execution paths occur: std::vector <T> v; custom_binary_iarchive ar(..); ar >> v; .... //goes in load_collection(Archive& ar, Container &s) collection_size_type count; ar>>BOOST_SERIALIZATION_NVP(count); .... //and finally reaches custom_binary_iarchive::load(non_integral_type &t); if instead I use polymorphic archive based on the custom_binary_iarchive I get: std::vector <T> v; polymorphic_iarchive_route<custom_binary_iarchive> ar(..); ar >> v; .... //in load_collection(Archive& ar, Container &s) collection_size_type count; ar>>BOOST_SERIALIZATION_NVP(count); ...... //goes into polymorphic_iarchive_impl::load_override(nvp<collection_size_type> &t) ..... //goes into polymorphic_iarchive_route::load(boost::ulong_long_t &t) //since collection_size_type has conversion to unsigned long long ... //and finally reaches custom_binary_iarchive::load(integral_type &t) The bottom line is that collection_size_type deserializes differently with polymorphic and regular archives. I am now trying to fix the problems by introducing overloads for all the serialization library's internal types, but it seems to me that some of those problems are actually bugs. Please advise on the best way to tackle this issues. Another question I have, and excuse me if this has been discussed (but I could not find it), is when should a custom archive overload save/load and when save_override/load_override? Thanks in advance, Nikolay Mladenov Sitius Automation Inc

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[serialization] 1.46 problems
by Nikolay Mladenov 03 Mar '11

03 Mar '11

I recently upgraded from 1.43 to 1.46 and this broke the serialization. We could not read archives save with 1.43. I the investigation i noticed the following issues. 1. in basic_binary_iarchive tracking_type is loaded as integer type or bool, but in basic_binary_oarchive it is stored as primitive type tracking_type. This breaks custom binary archives that have overloads for integer types and bools to be broken this problem probably applies to other internal serialization types (collection_size_type, version_type, etc), but I have not investigated this. 2. I have a custom binary archives which have overloads for integer types (loosely) like: class custom_binary_iarchive : boost::archive::binary_iarchive_impl<custom_binary_iarchive> { };

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[log] Current status
by Gregory Symons 02 Mar '11

02 Mar '11

Hi, I've been looking at Boost.Log, and I was wondering what it's current status is? It was provisionally accepted almost a year ago; any ideas when it will make it into a boost release? -- Gregory Symons <gsymons(a)drillinginfo.com> Developer DrillingInfo <http://www.drillinginfo.com>

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