June 2008 - Boost - lists.preview.boost.org

Review Wizard Status Report for May 2008
by Ronald Garcia 11 Jul '08

11 Jul '08

========================================== Review Wizard Status Report for May 2008 ========================================== News ==== December 7, 2007 - Forward Library Accepted - Awaiting SVN December 16 - Unordered Containers Library Accepted - In SVN December 21 - Factory Library Accepted - Awaiting SVN January 13, 2008 - Switch Library Accepted Provisionally - Awaiting submission for mini review January 18 - Singleton Library Rejected - Awaiting resubmission, John Torjo has already volunteered to manage the next review January 30 - Flyweight Library Accepted - Awaiting SVN February 13 - Logging Library Rejected - Awaiting resubmission for new review, John Torjo has already resubmitted and Gennadiy Rozental has again volunteered to manage the review February 27 - Floating Point Utilities Library Accepted - Awaiting SVN March 14 - Proto Library Accepted - Exists as a component in Xpressive, but not yet as a separate library April 20 - Egg review completed - Results pending May 7 - Scope Exit Library Accepted - Awaiting SVN Older Issues ============ The binary_int library, accepted in October 2005 has not yet been submitted to SVN. The authors are strongly encouraged to contact the review wizards The Quantitative Units library, accepted in April 2007 has not yet been submitted to SVN The Globally Unique Identifier library, accepted provisionally in May 2007 has not yet been submitted for mini-review and full acceptance The Time Series Library, accepted in August 2007 has not yet been submitted to SVN The Accumulators library, accepted in February 2007 is in SVN The Exception library, accepted in October 2007 is in SVN The Scope Exit review report had not been submitted by the review manager. John Phillips stepped in as substitute review manager and produced a report For libraries that are still waiting to get into SVN, please get them ready and into the repository. The developers did some great work making the libraries, so don't miss the chance to share that work with others. Also notice that the review process page has been updated with a section on rights and responsibilities of library submitters. For the Scope Exit review, we would like to publicly apologize to Alexander Nasonov for how long this has languished without a report. The review wizards will work to make sure this doesn't happen any more. General Announcements ===================== As always, we need experienced review managers. In the past few months there have been a large number of reviews, but the flow of high quality submissions is just as big, 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 or library contributors. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "garcia at cs dot indiana dot edu" and "phillips at mps dot ohio-state dot edu" respectively. 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. If you're a library author and plan on submitting a library for review in the next 3-6 months, send Ron or John a short description of your library and we'll add it to the Libraries Under Construction below. We know that there are many libraries that are near completion, but we have hard time keeping track all of them. Please keep us informed about your progress. Review Queue ============ * Finite State Machines * Property Map (fast-track) * Graph (fast-track) * Lexer * Thread-Safe Signals * Boost.Range (Update) * Shifted Pointer * DataFlow Signals * Logging * Futures (Braddock Gaskill) * Futures (Anthony Williams) * Join (Yigong Liu) * Pimpl (Vladimir Batov) -------------------- Finite State Machines --------------------- :Author: Andrey Semashev :Review Manager: Martin Vuille :Download: `Boost Sandbox Vault <http://tinyurl.com/yjozfn>`__ :Description: The Boost.FSM library is an implementation of FSM (stands for Finite State Machine) programming concept. The main goals of the library are: * Simplicity. It should be very simple to create state machines using this library. * Performance. The state machine infrastructure should not be very time and memory-consuming in order to be applicable in more use cases. * Extensibility. A developer may want to add more states to an existing state machine. A developer should also be able to specify additional transitions and events for the machine with minimum modifications to the existing code. Property Map (fast-track) ------------------------- :Author: Andrew Sutton :Review Manager: Jeremy Siek :Download: http://svn.boost.org/svn/boost/sandbox/graph-v2 :Description: A number of additions and modifications to the Property Map Library, including: * A constant-valued property map, useful for naturally unweighted graphs. * A noop-writing property map, useful when you have to provide an argument, but just don't care about the output. * See `ChangeLog <http://svn.boost.org/trac/boost/browser/sandbox/ graph-v2/libs/property_map/ChangeLog>`__ for details. Graph (fast-track) ------------------ :Author: Andrew Sutton :Review Manager: Jeremy Siek :Download: http://svn.boost.org/svn/boost/sandbox/graph-v2 :Description: A number of additions and modifications to the Graph Library, including: * Two new graph classes (undirected and directed) which are intended to make the library more approachable for new developers * A suite of graph measures including degree and closeness centrality, mean geodesic distance, eccentricity, and clustering coefficients. * An algorithm for visiting all cycles in a directed graph (Tiernan's from 1970ish). It works for undirected graphs too, but reports cycles twice (one for each direction). * An algorithm for visiting all the cliques a graph (Bron&Kerbosch). Works for both directed and undirected. * Derived graph measures radius and diameter (from eccentricity) and girth and circumference (from Tiernan), and clique number (from Bron&Kerbosch). * An exterior_property class that helps hides some of the weirdness with exterior properties. * run-time and compile-time tests for the new algorithms. * a substantial amount of documentation * Graph cores, implemented by David Gleich (@Stanford University) * Deterministic graph generators - capable of creating or inducing specific types of graphs over a vertex set (e.g., star graph, wheel graph, prism graph, etc). There are several other specific types that could be added to this, but I haven't had the time just yet. Lexer ----- :Author: Ben Hanson :Review Manager: Eric Neibler :Download: `Boost Sandbox Vault <http://boost-consulting.com/vault/ index.php? action=downloadfile&filename=boost.lexer.zip&directory=Strings%20-% 20Text%20Processing&>`__ :Description: A programmable lexical analyser generator inspired by 'flex'. Like flex, it is programmed by the use of regular expressions and outputs a state machine as a number of DFAs utilising equivalence classes for compression. Thread-Safe Signals ------------------- :Author: Frank Hess :Review Manager: Need Volunteer :Download: `Boost Sandbox Vault <http://www.boost-consulting.com/ vault/index.php?&direction=0&order=&directory=thread_safe_signals>`__ :Description: A thread-safe implementation of Boost.Signals that has some interface changes to accommodate thread safety, mostly with respect to automatic connection management. Boost.Range (Update) -------------------- :Author: Neil Groves :Review Manager: Needed :Download: `Boost Sandbox Vault <http://www.boost-consulting.com/ vault/index.php?action=downloadfile&filename=range_ex.zip&directory=>`__ :Description: A significant update of the range library, including range adapters. Shifted Pointer --------------- :Author: Phil Bouchard :Review Manager: Needed :Download: `Boost Sandbox Vault <http://www.boost-consulting.com/ vault/index.php?&direction=0&order=&directory=Memory>`__ :Description: Smart pointers are in general optimized for a specific resource (memory usage, CPU cycles, user friendliness, ...) depending on what the user need to make the most of. The purpose of this smart pointer is mainly to allocate the reference counter (or owner) and the object itself at the same time so that dynamic memory management is simplified thus accelerated and cheaper on the memory map. DataFlow Signals ---------------- :Author: Stjepan Rajko :Review Manager: Needed :Download: http://dancinghacker.com/code/dataflow/ :Description: Dataflow is a generic library for dataflow programming. Dataflow programs can typically be expressed as a graph in which vertices represent components that process data, and edges represent the flow of data between the components. As such, dataflow programs can be easily reconfigured by changing the components and/or the connections. Logging ------- :Author: John Torjo :Review Manager: Gennadiy Rozental :Download: http://torjo.com/log2/ :Description: Used properly, logging is a very powerful tool. Besides aiding debugging/testing, it can also show you how your application is used. The Boost Logging Library allows just for that, supporting a lot of scenarios, ranging from very simple (dumping all to one destination), to very complex (multiple logs, some enabled/some not, levels, etc). It features a very simple and flexible interface, efficient filtering of messages, thread-safety, formatters and destinations, easy manipulation of logs, finding the best logger/filter classes based on your application's needs, you can define your own macros and much more! Futures ------- :Author: Braddock Gaskill :Review Manager: Needed :Download: http://braddock.com/~braddock/future/ :Description: The goal of the boost.future library is to provide a definitive future implementation with the best features of the numerous implementations, proposals, and academic papers floating around, in the hopes to avoid multiple incompatible future implementations in libraries of related concepts (coroutines, active objects, asio, etc). This library hopes to explore the combined implementation of the best future concepts. Futures ------- :Author: Anthony Williams :Review Manager: Needed :Download: http://www.justsoftwaresolutions.co.uk/files/ n2561_future.hpp (code) http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/ n2561.html (description) :Description: This paper proposes a kind of return buffer that takes a value (or an exception) in one (sub-)thread and provides the value in another (controlling) thread. This buffer provides essentially two interfaces: * an interface to assign a value as class promise and * an interface to wait for, query and retrieve the value (or exception) from the buffer as classes unique_future and shared_future. While a unique_future provides move semantics where the value (or exception) can be retrieved only once, the shared_future provides copy semantics where the value can be retrieved arbitrarily often. A typical procedure for working with promises and futures looks like: * control thread creates a promise, * control thread gets associated future from promise, * control thread starts sub-thread, * sub-thread calls actual function and assigns the return value to the promise, * control thread waits for future to become ready, * control thread retrieves value from future. Also proposed is a packaged_task that wraps one callable object and provides another one that can be started in its own thread and assigns the return value (or exception) to a return buffer that can be accessed through one of the future classes. With a packaged_task a typical procedure looks like: * control thread creates a packaged_task with a callable object, * control thread gets associated future from packaged_task, * control thread starts sub-thread, which invokes the packaged_task, * packaged_task calls the callable function and assigns the return value, * control thread waits for future to become ready, * control thread retrieves value from future. Notice that we are in the unusual position of having two very different libraries with the same goal in the queue at the same time. The Review Wizards would appreciate a discussion of the best way to hold these two reviews to produce the best possible addition to Boost. 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 Sandbox Vault <http://www.boost-consulting.com/ vault/index.php?action=downloadfile&filename=Pimpl.zip&directory=&>`__ 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. Libraries under development =========================== Please let us know of any libraries you are currently developing that you intend to submit for review.

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[constrained_value] Formal review request
by Robert Kawulak 10 Jul '08

10 Jul '08

Dear Boosters, I'm glad to say the Boost Constrained Value library is finally ready for a formal review. To remind what this library is about, an excerpt from the motivation section of the documentation is attached at the bottom of this message. Jeff, you volunteered to be the review manager - is your proposition still up to date? If so, I'd be thankful if you could do the work. ;-) The code and documentation can be downloaded here: http://rk.go.pl/f/constrained_value.zip The documentation is also available online here: http://rk.go.pl/r/constrained_value The only thing that's missing is test programs - I will try to add them during/after the review. The changes made since previous version: - rewritten the documentation at some points and added tutorial, - no more value generators - direct types or MPL integral constants are used instead, - bounded types use bounds exclusion instead of inclusion (so bounds are included by default in all cases), - changed order and default values of some of template parameters, - removed throw_verbose_exception error policy, - made other minor fixes and improvements. As always, feedback is welcome. Best regards, Robert Kawulak FROM THE MOTIVATION SECTION OF THE DOCUMENTATION: The Boost Constrained Value library contains class templates useful for creating constrained objects. A simple example is an object representing an hour of a day, for which only integers from the range [0, 23] are valid values: bounded_int<int, 0, 23>::type hour; hour = 20; // OK hour = 26; // exception! Behavior in case of assignment of an invalid value can be customized. For instance, instead of throwing an exception as in the example above, the value may be adjusted to meet the constraint: wrapping_int<int, 0, 255>::type buffer_index; buffer_index = 257; // OK: adjusts the value to fit in the range by wrapping it assert( buffer_index == 1 ); The library doesn't focus only on bounded objects as in the examples above -- virtually any constraint can be imposed by using a predicate: // constraint (a predicate) struct is_odd { bool operator () (int i) const { return (i % 2) != 0; } }; // and the usage is as simple as: constrained<int, is_odd> odd_int = 1; odd_int += 2; // OK ++odd_int; // exception! The library has a policy-based design to allow for flexibility in defining constraints and behavior in case of assignment of invalid values. Policies may be configured at compile-time for maximum efficiency or may be changeable at runtime if such dynamic functionality is needed.

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[Boost.Log1]: Bug in boost/log/detail/ts_posix.hpp
by Jens Seidel 09 Jul '08

09 Jul '08

Hi, I know that version 1 of John's logging library was never accepted and is probably not wildly used anymore nevertheless I found a nasty bug in it. It's strange but even after applying valgrind I found initially not the reason (probably I just assumed John's code is OK and it's something else) and it took some time until I resolved it. OK, for all users of this lib here is the patch: boost/log/detail/ts_posix.hpp: @@ -51,7 +51,7 @@ mutex & operator = ( const mutex & Not_Implemented); mutex( const mutex & From); public: - mutex() : m_mutex() { + mutex() : m_mutex(), m_count(0) { pthread_mutexattr_t attr; int res = pthread_mutexattr_init(&attr); assert(res == 0); I haven't checked whether this occurs in version 2 as well. Jens

3 3

[test][darwin][trunk] using some undefined signal macros on Power PC
by JOAQUIN M. LOPEZ MUÑOZ 07 Jul '08

07 Jul '08

Hello, I guess it is pretty apparent by now, but Boost.Test is causing a lot of regressions in the Sandia-darwin-ppc regression runner with the following: http://tinyurl.com/689u7x ../boost/test/impl/execution_monitor.ipp: In member function 'void boost::detail::system_signal_exception::report() const': ../boost/test/impl/execution_monitor.ipp:292: error: 'ILL_ILLOPN' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:297: error: 'ILL_ILLADR' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:312: error: 'ILL_PRVREG' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:317: error: 'ILL_COPROC' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:322: error: 'ILL_BADSTK' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:332: error: 'FPE_INTDIV' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:337: error: 'FPE_INTOVF' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:367: error: 'FPE_FLTSUB' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:397: error: 'BUS_ADRERR' was not declared in this scope ../boost/test/impl/execution_monitor.ipp:402: error: 'BUS_OBJERR' was not declared in this scope AFACIS <signal.h> does not define these macros in Power PC architectures, further confirmation of this fact here http://source.winehq.org/source/dlls/ntdll/signal_powerpc.c I guess it's easy enough to conditionally #define the offending parts out relying on defined(__POWERPC__). I'd propose a patch mysel but I don't have the appropriate environment to test locally with. And unfortunately we don't have a Darwin/PPC champion yet: http://svn.boost.org/trac/boost/wiki/PlatformChampions HTH, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

5 5

[utility/swap] Okay to add array support to Boost.Swap (sandbox/swap)?
by Niels Dekker - mail address until 2008-12-31 06 Jul '08

06 Jul '08

Hi Joe, hi Steven, Would it be okay to you if we would add support for array types to the Boost.Swap utility that is located in the sandbox? I'm asking now, because I wrote an issue, asking the C++ Standards Committee to add an overload of std::swap for array types. And Howard Hinnant just mailed me the other day that the issue has reached status Ready. :-) LWG issue 809, "std::swap should be overloaded for array types" http://home.twcny.rr.com/hinnant/cpp_extensions/issues_preview/lwg-active.h… Of course, it will still take a while before STL implementations will actually add such an std::swap overload. It isn't yet part of the Standard, officially. So I would very much appreciate if boost::swap would already start supporting array types. And I think it would be helpful when implementing swap member functions for templates like boost::value_initialized<T>. Array support could easily be added to swap/boost/utility/swap.hpp (http://svn.boost.org/trac/boost/browser/sandbox/swap/boost/utility/swap.hpp) by overloading boost_swap_impl::swap_impl, as follows: template<class T, std::size_t N> void swap_impl(T (& left)[N], T (& right)[N]) { for (std::size_t i = 0; i < N; ++i) { ::boost_swap_impl::swap_impl(left[i], right[i]); } } Please tell me what you think. I do have SVN write access, so I wouldn't mind committing the necessary changes. :-) Kind regards, -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

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Inspection report and non-ASCII characters
by John Maddock 05 Jul '08

05 Jul '08

Would it be possible for the inspection report to print out the line containing the non-ASCII characters? There are a few files that are being flagged up, where I just can't find anything wrong with them :-( Thanks, John.

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[dynamic_bitset] bug in to_ulong() in dynamic_bitset.hpp
by Boris Gubenko 05 Jul '08

05 Jul '08

A failure of dynamic_bitset library test dyn_bitset_unit_tests3 on Tru64/cxx and HP-UX/aCC revealed what appears to be a bug in <boost/dynamic_bitset/dynamic_bitset.hpp> introduced after Boost 1.34. The bug affects platforms where 'long' type is larger than 'int'. On both Tru64 and HP-UX, 'int' is a 32-bit type. On Tru64, 'long' is a 64-bit type. On HP-UX, 'long' is a 64-bit type in 64-bit data model (+DD64, which is how Boost testing is done on this platform) and 32-bit type otherwise. The test also fails on other platforms and while I cannot verify it, from the test output it apears that these platforms are affected by the same bug. What fails is the two testcases below in b.to_long() suite in boost/libs/dynamic_bitset/dyn_bitset_unit_tests3.cpp invoked with run_test_cases<unsigned int>() : { std::string str(ul_width - 1, '1'); boost::dynamic_bitset<Block> b(str); Tests::to_ulong(b); } { std::string ul_str(ul_width, '1'); boost::dynamic_bitset<Block> b(ul_str); Tests::to_ulong(b); } The code in <boost/libs/dynamic_bitset/bitset_test.hpp> converts dynamic_bitset<unsigned int> argument to unsigned long and checks that the appropriate bits in the result are set: result_type num = lhs.to_ulong(); // Be sure the number is right if (sz == 0) BOOST_CHECK(num == 0); else { for (std::size_t i = 0; i < sz; ++i) BOOST_CHECK(lhs[i] == (i < n ? nth_bit(num, i) : 0)); } This check fails for the bits in the upper half of the result. Here is an excerpt from dynamic_bitset<Block, Allocator>::to_ulong() function in <boost/dynamic_bitset/dynamic_bitset.hpp> in the trunk: result_type result = 0; for (size_type i = 0; i <= last_block; ++i) { assert((size_type)bits_per_block * i < (size_type)ulong_width); result |= (m_bits[i] << (bits_per_block * i)); } In our case, last_block = 1 and bits_per_block = 32. m_bits[i] has 'unsigned int' type. On the second loop iteration, a 32-bit integer is left-shifted by 32 bit positions. This triggers undefined behaviour. From 5.8 - Shift operators [expr.shift] : "The behavior is undefined if the right operand is [...] greater than or equal to the length in bits of the promoted left operand." With cxx and aCC, such shift results in zeroing of all bits of the left operand. Here is the code from <boost/dynamic_bitset/dynamic_bitset.hpp> in Boost 1.34 : unsigned long result = 0; for (size_type i = 0; i <= last_block; ++i) { assert((size_type)bits_per_block * i < (size_type)ulong_width); // gps unsigned long piece = m_bits[i]; result |= (piece << (bits_per_block * i)); } Here on the second loop iteration, a 64-bit long is left-shifted by 32 bit positions which yields the intended result. x.cpp below illustrates the difference between trunk and Boost 1.34: x.cpp ----- #include <stdio.h> #include <limits.h> int main() { unsigned int m_bits[] = { UINT_MAX, UINT_MAX }; unsigned int bits_per_block = sizeof(int) * CHAR_BIT; unsigned long result = 0; for(int i = 0; i <= 1 ; ++i) { #ifndef Boost_1_34 result |= (m_bits[i] << (bits_per_block * i)); #else unsigned long piece = m_bits[i]; result |= (piece << (bits_per_block * i)); #endif printf("result = %llx\n", result); } } cxxosf.zko.hp.com> cxx x.cpp && a.out result = ffffffff result = ffffffff cxxosf.zko.hp.com> cxx x.cpp -DBoost_1_34 && a.out result = ffffffff result = ffffffffffffffff cxxosf.zko.hp.com> Replacing result |= (m_bits[i] << (bits_per_block * i)); with unsigned long piece = m_bits[i]; result |= (piece << (bits_per_block * i)); on the trunk makes the test succeed: verified on Tru64/cxx and on HP-UX/aCC. In <http://lists.boost.org/Archives/boost/2007/12/131126.php> I said: > It looks like a regression in boost/dynamic_bitset/dynamic_bitset.hpp > introduced in 1.35, but even in 1.34.1, it seems to me that the code in > to_ulong() is relying on undefined behaviour. What I was referring to is the code in 1.34 applying bitwise shift operator to a long operand. It would trigger an undefined behavior in C where "The operands shall have integer type", but it is legal in C++ where "The operands shall be of integral or enumeration type". So, I no longer claim that the code in 1.34 is relying on undefined behaviour. And the last thing: why the bug affects only platforms where 'long' type is larger than 'int'? Because if they are the same, as is the case on VMS or HP-UX in 32-bit data model, last_block = 0 and the single iteration of the for loop just assigns m_bits[0] to the result: the right operand of the shift operator is zero. To fix the problem, I suggest to replace the buggy code in <boost/dynamic_bitset/dynamic_bitset.hpp> in the trunk with that in 1.34. If there are no objections, I can do it. Thanks, Boris

3 3

[math] pow redux and observations
by John Moeller 05 Jul '08

05 Jul '08

I noticed that the trunk now has corrections for pow<N> to reduce template instantiations. However, the "N=1" specialization isn't correct. The second template parameter (bool odd) should be "true," not "false." I could be mistaken that 1 is an odd number, though. :-) As it is now, the whole template would work, but would ignore the 1/false specialization and create a new 1/true specialization that just multiplies "base" by the result of 0/false. Changing 1/false to 1/true will just cause it to return "base," as desired. Note also, please, that positive_power<0,false> returns 1 when base is 0. Since 0^0 is technically undefined, the "N=0" case should probably be handled at a higher level (in power_if_positive, perhaps), and cause an error, just like negative powers of 0. If that is done, the 0/false case could be removed from positive_power.

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libs/dynamic_bitset/bitset_test unmerged changes?
by David Abrahams 05 Jul '08

05 Jul '08

Should these be in the trunk? Index: bitset_test.hpp =================================================================== --- bitset_test.hpp (revision 40672) +++ bitset_test.hpp (working copy) @@ -1006,7 +1006,8 @@ bool did_throw = false; try { - s << b; + static_cast<void> + (s << b); } #if defined BOOST_OLD_IOSTREAMS catch(...) { @@ -1081,7 +1082,8 @@ const std::ios::iostate except = is.exceptions(); bool has_stream_exceptions = true; try { - is >> b; + static_cast<void> + (is >> b); } catch(const std::ios::failure &) { did_throw = true; -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

2 1

[allocators] Article and library about allocator improvements
by Ion Gaztañaga 03 Jul '08

03 Jul '08

Hi, While developing of Interprocess, I started to think about optimizations for STL-like allocators. I even wrote a proposal about some new features for standard containers (N2045, http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2045.html) that was not received with much interest by the committee. I refined those improvements for shared memory containers and I measured performance benefits when containers take advantage of more advanced allocators. The last few months, I've taken another step forward and I've developed a small Boost library based on a modified DLmalloc code. I've developed some allocators above the modified DLmalloc and I've measured the performance benefits that can be obtained with optimized allocators that offer some new features like buffer expansion, burst allocation, etc... Test were performed using Interprocess containers, but instead of shared memory allocators, I've compared DLmalloc based heap allocators against the standard std::allocator<>. I've written a long article with my explanations and conclusions: http://www.drivehq.com/web/igaztanaga/allocplus/ The library (includes the article) can be downloaded here: http://www.drivehq.com/web/igaztanaga/allocplus.zip The library has no docs (the article explains all the basics) and does not surely meet Boost standards. The only goal of this article, the library and this post is to share information with other Boost container authors and discuss possible improvements that maybe could be applied to Boost containers. If those improvements are considered interesting, it would be great if we could write a library with allocators and develop some "existing practice" with boost containers before writing a future proposal to improve allocators. I plan to publish the article somewhere (supposing someone is crazy enough to publish it ;-) ) but first I wanted to share this with boosters to try to improve the article/library and know if developers are interested in allocator issues. Comments are welcome! Regards, Ion

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A branching/tagging idea for releases
by Daryle Walker 03 Jul '08

03 Jul '08

Here's an idea on how we can manage our source-control for releases: 1. When we're ready to start a new release, make a branch from the trunk with a name like release_1_??_x (e.g. "release_1_37_x") 2. Finalize what needs to be done to make that branch ship-worthy 3. Make a tag from that branch with a name like release_1_??_0 (e.g. "release_1_37_0") 4. Export that tag to a fresh directory and create the appropriate archive file to upload to SourceForge, etc. (The directory shouldn't have any source-control debris in it. Maybe this needs to be done once on each platform to ensure the best archive format and the proper line-ending markers.) 5. If bug-fixes for that release need to be done, continue to use the release_1_??_x branch (and merge the fixes back to the trunk, or vice versa) 6. Make a new tag named like release_1_??_1 and ship it as in [4] for any bug-fix releases (increase the number for subsequent bug- fixes published) 7. New stuff and substantial changes go on the trunk; publish those by going back to [1] with a release_1_(??+1)_x branch -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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Documentation for Boost libraries
by Edward Diener 03 Jul '08

03 Jul '08

In general Boost has many libraries with good to absolutely first class documentation. Among the many Boost libraries I have used, all with good documentation, are regex, iostreams, function, bind, optional, signals. tribool, tokenizer, and spirit, but of course there are many other libraries with great documentation in Boost. One of my prerequisites for a library with good documentation is that some sort of overview must be given for the functionality of the library so that the end user knows what is available, and what each available part of the library generally entails. For me this overview must be written out and not just given as a series of programming examples, whether in the form of tutorial code, example code, or whatever one wants to call explanations of functionality based almost purely on some hypothetical program or mini-program. In this I may be different from many programmers but I just find it very hard to understand library functionality from example code without basic generalized explanations of functionality. Today, looking for a socket library to use in my C++ code I decided to look at the documentation for ASIO. I was shocked to find out that there is no overview of the functionality of this library at all, but just a series of tutorials and examples and then a reference listing a multitude of classes. I do not believe this is adequate for explaining library functionality and puts a totally unnecessary burden of the end-user when learning the functionality of a library. I would like to encourage Boost developers to always give an overview of the functionality of their library and its general concepts and classes, as almost all libraries currently do. While I am appreciative of tutorials and exmaples as an extra learning device, I do not believe that library documentation should exist with some sort of overview, as mentioned above. I have written this because I am disturbed that ASIO was accepted with the sort of documentation which has been created for it. I do not think such a way of presenting a library is adequate for an organization like Boost whose overall excellence is acknowledged throughout the C++ community.

6 12

Is "+" safe for file names?
by Rene Rivera 02 Jul '08

02 Jul '08

Just noticed this directory name: libs/filesystem/test/vc++.boost.filesystem Is "+" safe to use across file systems? Hm, actually I'm fairly sure more than one "." is not safe. For example in the MVS systems? -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org (msn) - grafik/redshift-software.com -- 102708583/icq - grafikrobot/aim,yahoo,skype,efnet,gmail

7 11

[asio] failure in ~wrapped_handler
by Dean Michael C. Berris 02 Jul '08

02 Jul '08

Hi everyone, I recently ran into a problem with Boost.Asio while using a slightly modified version of the HTTP 2 example server. The debugger trace (attached) shows where a segfault had occurred in the code. The short of it is that when ~wrapped_handler is called, the call to boost::detail::atomic_exchange_and_add fails when boost::detail::sp_counted_base::release is invoked. It occurs when a handler_wrapper is deleted/destructed (~handler_wrapper is called) in the strand_service. I'm just wondering what could be causing this -- it's worth noting that under not-so-heavy load, the problem does not manifest itself; but soon enough when the load on the server goes up (more incoming connections) the server crashes consistently. Any pointers where I should be looking? I'm using Boost.Trunk revision number 43296. -- Dean Michael Berris Software Engineer, Friendster, Inc.

3 2

Anyone interested in a generic loop (and loop unrolling) library ?
by Hui Li 01 Jul '08

01 Jul '08

Loops, in particular loop-unrolling, can be made generic, easy to write, and accessible to everybody. With the help of Boost.Lambda (and a few other boost libraries), we can easily construct arbitrary loops that are unrolled at compile-time. I haven't implemented the full library yet, in fact I've implemented only a few very preliminary functionalities (hardly flawless), it serves only to illustrate the ideas. From what they can do, a possible Boost.Loop library looks very promising. However I feel that I need much help on the design of such a library. The implementation could be straightforward (with the help of so many good libraries in Boost), once a good design is found. Hopefully there are interested people here so I won't have to work on my own. (If there already exists such a library, please let me know.) In the example, you can see how easy it is to construct arbitrary (limited only by Boost.Lamda) loops that are generically unrolled at compile time. With an optimizing compiler, it can be as efficient as hand-written codes. Not only that, but also can we make (almost) any linear-algebra libraries work together without difficulty. In the example, we don't need any extra coding to make a c_array, std::vector, or even a column_view of a ublas::matrix to work together. In the following I give the full example code to illustrate what it's capable of and how to use it. The header file, loop.hpp, is attached at the end of this post. The example has been tested with apple-gcc4.0.1 . Thanks, Hui /**********************************************************************************************************/ #include <vector> #include <iostream> #include <iterator> #include <functional> #include <boost/array.hpp> #include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/matrix_proxy.hpp> #include <boost/numeric/ublas/io.hpp> #include "loop.hpp" using namespace std; using namespace boost; using namespace boost::lambda; using namespace boost::numeric; using namespace boost::numeric::ublas; using namespace loop; int idt(int i) { return i; } int main(int argc, char* argv[]) { const size_t N = 8, M = 3; boost::array<double,N> v; std::vector<double> w(N); matrix<double> m(N,M); // All loops are unrolled at compile time // indtrans acts like an array whose individual element equals its index index_transform<double(int)> indtrans(&idt); // equivalent to for(i=0;i<N;i+=2){ v[i]=w[i]=1; } loop_over< linear_range<0,N,2> >( _1 = _2 = 1, v, w ); // equivalent to for(i=1;i<N;i+=2){ v[i]=i; } loop_over< linear_range<1,N,2> >( _1 = _2, v, indtrans ); // equivalent to for(i=1;i<N;i+=2){ w[i]=i; } loop_over< linear_range<1,N,2> >( _1 = _2, w, indtrans ); // loop_over< linear_range<1,N,2> >( _1 = _2 = _3, v, w, indtrans ); // I wonder why this line doesn't compile with gcc4?? m.clear(); // set m to a zero matrix // equivalent to for(i=1;i<N;++i){ column(m,2)[i]=1+i*2; } loop_over< linear_range<0,N,1> >( _1 = 1+_2*2, loop::ref(column(m,2)), indtrans ); // equivalent to for(i=1;i<2;++i){ v[i]*=-2; } followed by for(i=N-3;i<N;++i){ v[i]*=-2; } loop_over< link_range<linear_range<0,2,1>,linear_range<N-3,N,1> > >( _1 *= -2, v); // vertically print out v and w, side by side loop_over< linear_range<0,N,1> >( cout << _1 << constant('\t') << _2 << constant('\n'), v, w ); cout<<endl; // print out m cout << m << endl << endl; double s = 0; // calculate the inner-product of w and column(m,2) (when the column is viewed as a vector/array) loop_over< linear_range<0,N,1> >( _1 += _2*_3, loop::ref(loop::scalar(s)), w, loop::ref(column(m,2)) ); cout << s << endl << endl; return 0; } /**********************************************************************************************************/ Here is the loop.hpp /********************************************************************************************************** * loop.hpp * Created by Hui Li on 6/26/08. ******************************************************************************************************** */ #ifndef LOOP_H #define LOOP_H #include <boost/static_assert.hpp> #include <boost/ref.hpp> #include <boost/lambda/lambda.hpp> #include <boost/function.hpp> #include <boost/function_types/function_arity.hpp> #include <boost/mpl/if.hpp> #include <boost/mpl/bool.hpp> #include <boost/mpl/assert.hpp> namespace loop { // the empty range struct empty_range {}; // a range starting from Start, ending at End, with stride Stride template < int Start, int End, int Stride = 1 > struct linear_range { BOOST_MPL_ASSERT(( boost::mpl::bool_<(Start*Stride<End*Stride)> )); static const int first = Start; typedef typename boost::mpl::if_ < boost::mpl::bool_< ((Start+Stride)*Stride < End*Stride) >, linear_range < Start+Stride, End, Stride >, empty_range >::type next_range; }; // link two arbitrary ranges template < typename LeftRange, typename RightRange > struct link_range { static const int first = LeftRange::first; typedef typename boost::mpl::if_ < typename boost::is_same < typename LeftRange::next_range, empty_range >::type, RightRange, link_range < typename LeftRange::next_range, RightRange > >::type next_range; }; // implementation of the unrolled loop over a range template < typename LambdaExpr, typename Range > struct loop_Impl { template < typename V1 > void operator()(LambdaExpr& expr, V1& v1) { expr(v1[Range::first]); loop_Impl < LambdaExpr, typename Range::next_range >()(expr,v1); } template < typename V1, typename V2 > void operator()(LambdaExpr& expr, V1& v1, V2& v2) { expr(v1[Range::first],v2[Range::first]); loop_Impl < LambdaExpr, typename Range::next_range >()(expr,v1,v2); } template < typename V1, typename V2, typename V3 > void operator()(LambdaExpr& expr, V1& v1, V2& v2, V3& v3) { expr(v1[Range::first],v2[Range::first],v3[Range::first]); loop_Impl < LambdaExpr, typename Range::next_range >()(expr,v1,v2,v3); } }; // looping over an empty range does nothing template < typename LambdaExpr > struct loop_Impl < LambdaExpr, empty_range > { template < typename V1 > void operator()(LambdaExpr&, V1){} template < typename V1, typename V2 > void operator()(LambdaExpr&, V1&, V2&){} template < typename V1, typename V2, typename V3 > void operator()(LambdaExpr&, V1&, V2&, V3&){} }; // helper functions template < typename Range, typename LambdaExpr, typename V1 > void loop_over(LambdaExpr& expr, V1& v1) { loop_Impl<LambdaExpr,Range>()(expr,v1); } template < typename Range, typename LambdaExpr, typename V1, typename V2 > void loop_over(LambdaExpr& expr, V1& v1, V2& v2) { loop_Impl<LambdaExpr,Range>()(expr,v1,v2); } template < typename Range, typename LambdaExpr, typename V1, typename V2, typename V3 > void loop_over(LambdaExpr& expr, V1& v1, V2& v2, V3& v3) { loop_Impl<LambdaExpr,Range>()(expr,v1,v2,v3); } // map a call to operator[] to a unary function all template < typename Function > struct index_transform { BOOST_STATIC_ASSERT(( boost::function_types::function_arity<Function>::value == 1 )); typedef boost::function<Function> func_type; typename func_type::result_type operator[](typename func_type::argument_type x) { return func(x); } template < typename FuncTp > index_transform(FuncTp f):func(f){} private: func_type func; }; // force removal of const-ness of a reference // not so elegant but should be okay template < typename T > T& ref(const T& t) { return const_cast<T&>(t); } // independent of whatever the index might be, it always returns the reference to the same variable template < typename T > struct scalar_Impl { T& operator[](int) { return ref; } scalar_Impl(T& t):ref(t){} private: T& ref; }; // scalar helper template < typename T > scalar_Impl<T> scalar(T& t) { return scalar_Impl<T>(t); } } // namespace loop #endif /**********************************************************************************************************/

4 3

[system] boost compilation
by simonvifr＠voila.fr 01 Jul '08

01 Jul '08

Hello, I contact you because an error occurs when compiling the "system" library with the following command prompt : bjam --with-system --toolset=intel --debug-configuration stage The intel compiler seems to be invoked correctly (see mail below). The message error is : error_code.cpp libs\system\src\error_code.cpp(90): error: namespace "std" has no member "strerror" const char * c_str = std::strerror( ev ); ^ compilation aborted for libs\system\src\error_code.cpp (code 2) My OS version is Windows XP. My boost version is 1.35.0 My boost-jam version is 3.1.16-1 (ntx86) My intel compiler version is 10.1.021 Thank you for your answer to fix this error. Regards. > Message du 29/06/08 à 16h30 > De : "Vladimir Prus" <ghost(a)cs.msu.su> > A : simonvifr(a)voila.fr > Copie à : boost-build(a)lists.boost.org > Objet : Re: [Boost-build] boost compilation > > > On Sunday 29 June 2008 18:14:43 simonvifr(a)voila.fr wrote: > > > > Hello, > > > > It is now ok for running the icl.exe in the same command prompt. > > However the following command prompt generate errors : bjam --with-system --toolset=intel stage > > I have then added "--debug-configuration" but I have still errors when executing the command prompt : bjam --with-system --toolset=intel --debug-configuration stage > > > > The error messages are : > > > > error_code.cpp > > libs\system\src\error_code.cpp(90): error: namespace "std" has no member "strerror" > > const char * c_str = std::strerror( ev ); > > ^ > > compilation aborted for libs\system\src\error_code.cpp (code 2) > > Okay, so it appears that the intel compiler is invoked correctly, and then reports > an error of the source code itself. At this point, I don't think it's Boost.Build > issue, but either issue with the Boost.System library, or the Intel compiler -- I > suggest you ask at boost(a)lists.boost.org, making sure "[system]" is in email subject. > > > An other error message is : > > > > notice: [cmdline-cfg] Detected command-line request for intel: toolset= intel version= > > notice: [cmdline-cfg] toolset intel not previously configured; attempting to auto-configure now > > What makes you think this is an error message -- it is not. > > - Volodya > ____________________________________________________ Sur le mail Voila, vous pouvez personnaliser l’anti-spam ! http://mail.voila.fr

2 1

[system] LWG issue 805 name changes applied
by Beman Dawes 01 Jul '08

01 Jul '08

The C++ committee's LWG issue 805 has been applied to Boost.System in trunk, using a namespace and enum as a workaround for non-availability of C++ scoped enums. This changes names: posix_errno -> errc posix_category -> generic_category get_posix_category -> get_generic_category "POSIX" -> "GENERIC" The old names are still supported as deprecated synonyms, so virtually no existing code is expected to break. The changes tested OK locally on Windows against Boost.Filesystem and Boost.ASIO. Let me know if any problems arise. Thanks, --Beman

3 2

error_code and error_category problem
by Berserker 01 Jul '08

01 Jul '08

In my project (using asio) I have something like this: void Foo::myCallback(const boost::system::error_code &e) { if(e == boost::asio::error::operation_aborted) { // bla bla... } } This call is made across a shared dll and I notice that for a "strange" reason e == boost::asio::error::operation_aborted was always false. I discover that when the temporary object boost::system::error_code is constructed from the constants boost::asio::error::operation_aborted the error_code's costructor take a pointer to a "error_category" and the comparison operator is (m_cat is an error_category pointer): inline friend bool operator==( const error_code & lhs, const error_code & rhs ) { return lhs.m_cat == rhs.m_cat && lhs.m_val == rhs.m_val; } In my situation (using shared modules) lhs.m_cat == rhs.m_cat points to differents memory regions (even if are of the same type "system_category") because of the static initialization in the function "get_system_category". The problem exist in the comparison operator of error_category too: bool operator==(const error_category & rhs) const { return this == &rhs; } I suggest to change the comparison criteria (for example using an enumerated value) _________________________________________________________________ Sai che con Messenger guardi la TV con i tuoi amici? http://www.messenger.it/messengertv.html

2 1

[interprocess] Bug in os_file_functions.hpp
by Lars Hagström 01 Jul '08

01 Jul '08

Hi, I've just tried to use the file_locks from the boost trunk, and stumbled across a bug (well, two related bugs, really) when using the try_lock* metods. The problem occurs on linux systems only. The try_acquire_file_lock_sharable and try_acquire_file_lock functions both have the following code in them: int ret = ::fcntl(hnd, F_SETLK, &lock); if(ret == -1){ return (errno != EAGAIN && errno != EACCES) ? acquired = false, true : false; } I believe this should be changed into int ret = ::fcntl(hnd, F_SETLK, &lock); if(ret == -1){ return (errno == EAGAIN || errno == EACCES) ? acquired = false, true : false; } (its the errno checking line that is changed) Without my fix the result of trying to lock a lock that someone else has is an exception. Cheers Lars

2 2

Re: [boost] [exception] - bug in tutorial -> member 'what' is ambiguous?
by Kowalke Oliver (QD IT PA AS) 30 Jun '08

30 Jun '08

Hi, I revering to http://svn.boost.org/svn/boost/trunk/libs/exception/doc/tutorial_transporti… First example: class my_error: public boost::exception<http://svn.boost.org/svn/boost/trunk/libs/exception/doc/exception.html>, public std::exception { }; //(2) This code line produces the error. Oliver On 6/18/08, Kowalke Oliver (QD IT PA AS) <Oliver.Kowalke <at> qimonda.com> wrote: > Yes I used the latest documentation from trunk: > Tutorial: Transporting of Abritrary Data to the Catch Site: > > class my_error : public boost::exception , std::exception {); > > Does not work with gcc-4.2.4 (compiler bug?). What exactly doesn't work on gcc-4.2.4? All of the examples from the documentation are in this folder: http://svn.boost.org/svn/boost/trunk/libs/exception/example/ The examples compile with msvc and gcc 4.3.1. I also looked at http://svn.boost.org/svn/boost/trunk/libs/exception/doc/transporting_data.h… I don't see a reference to what() in it. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode > On Tue, Jun 17, 2008 at 12:09 AM, Kowalke Oliver (QD IT PA AS) <Oliver.Kowalke <at> qimonda.com> wrote: > > Hi, > > I'm using boost.exception from trunk and I get following error (gcc-4.2.4): > > > > error: request for member 'what' is ambiguous > > /usr/include/c++/4.2/exception:64: error: candidates are: virtual > > const char* std::exception::what() const > > /opt/boost/include/boost-1_35/boost/exception/exception.hpp:52: error: > > virtual const char* boost::exception::what() const > > > > I'm using the code from the boost.exception tutorial: > > > > class error > > : > > public boost::exception, > > public std::exception > > {} > > > > ... > > try > > {...} > > catch ( error const& e) > > { std::cout << "error: " << e.what() << std::endl; } > > Where do you read the tutorial you are mentioning? Is it possible that it is out of date? The latest documentation can be accessed directly through the subversion web interface: > > http://svn.boost.org/svn/boost/trunk/libs/exception/doc/boost-exception.html. > > Emil Dotchevski > Reverge Studios, Inc. > http://www.revergestudios.com/reblog/index.php?n=ReCode > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

2 3

[spirit] Deprecation warnings, can they be turned off?
by Rene Rivera 30 Jun '08

30 Jun '08

In doing a top-level build of Boost (trunk) I'm seeing many messages like this one: ./boost/spirit/core/composite/actions.hpp:15:4: warning: #warning "This header is deprecated. Please use: boost/spirit/include/classic_actions.hpp" In file included from libs/serialization/src/basic_xml_grammar.ipp:22, from libs/serialization/src/xml_wgrammar.cpp:243: Two questions: * Is this something to worry about that the Serialization lib, and perhaps others, are using the deprecated headers? * Assuming Serialization, other libraries, and users want to use the old headers. Is there a way for them to turn off the warning? I don't see anything obvious from looking at the headers themselves. In a world where compiling Boost produces many warnings already in some platforms. It seems bad if we are adding even more onto the fray. -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org (msn) - grafik/redshift-software.com -- 102708583/icq - grafikrobot/aim,yahoo,skype,efnet,gmail

3 5

Need help with Boost:Serialization!
by Daniel Kunz 30 Jun '08

30 Jun '08

Hi, I'm very new at Boost and want to develop a project for school with the Boost:Serialization package. I've already read the documantation and serveral other sources. I'm not very good in programming C++, so please excuse that my code looks not perfect. I hope it's ok that I've posted some sourcecode. I've tried to keep it short... *My problem:* I have to create a program to serialise and deserialse a xml-file to a binary-stream. I think to binary stream is already done but the xml-serialisation is not ready and I don't know whats wrong. I have 3 classes: Goal ------------ class Goal { private: enum Scored{home=0, visitors=1}; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & name; ar & minute; ar & shootout; ar & scored; ar & penality; } string name; int minute; bool shootout; Scored scored; bool penality; public: Goal(){}; Goal(const string _name, int &_minute, bool &_shootout, Scored &_scored, bool &_penality); ~Goal(){}; friend ostream & operator<<(ostream &os, const Goal &_goal); }; --------------- Stadium --------------- class Stadium { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & name; ar & city; ar & spectators; } string name; string city; int spectators; public: Stadium(){}; Stadium(const string _name, const string _city, int &_spectators); friend ostream & operator<<(ostream &os, Stadium &_stadium); }; ---------------- and Match ---------------- class Match { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & home; ar & visitors; ar & kickoff; /*lGoals::const_iterator pos; for (pos = goals.begin(); pos != goals.end(); pos++) { ar & pos; }*/ ar & BOOST_SERIALIZATION_NVP(goals); ar & stadium; } string home; string visitors; time_t kickoff; typedef list<Goal> lGoals; lGoals goals; Stadium stadium; public: Match(){}; Match(const string _home, const string _visitors, time_t &_kickoff, Goal _goals[100], Stadium &_stadium); Match& operator = (Match &_match); friend ostream & operator<<(ostream &out, Match &_match); }; ---------------- Now I have to serialise this classes in an xml structure. Therefor I've created the file xml.h/.cpp. I only post the xml.cpp here: ---------------- #include <iomanip> #include <iostream> #include <fstream> #include <string> #include "goal.h" #include "stadium.h" #include "match.h" #include <boost/serialization/base_object.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/list.hpp> #include <boost/serialization/is_abstract.hpp> #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/xml_oarchive.hpp> //Tracing and Logging module //#include "Logger.h" //#include "Tracer.h" using namespace std; /** * \brief Fuction to Deserialise a xml-file to an object structure * \param const Match &m, const string &filename * \return void */ void save_xml(const Match &m, const string &filename){ // make an archive ofstream ofs(filename.c_str()); boost::archive::xml_oarchive oa(ofs); //fill data to archive oa <<BOOST_SERIALIZATION_NVP(m); ofs.flush(); } /** * \brief Fuction to Serialise an object structure to a xml-file * \param Match &m, const string &filename * \return void */ void restore_xml(Match &m, const string &filename) { // open the archive ifstream ifs(filename.c_str()); boost::archive::xml_iarchive ia(ifs); //restore the data from the archive ia >>BOOST_SERIALIZATION_NVP(m); } ---------------- So thats it and I hope its not all wrong I tried. I hope you can help me finish that project. Thanks!

3 6

[date_time] Documentation Fix (time_period)
by Bryan Petty 30 Jun '08

30 Jun '08

Hi, Attached is a quick patch to switch the placement of the time_period(ptime,ptime) and time_period(ptime,time_duration) examples to their correct locations. Regards, Bryan Petty

2 2

Trac "search" link doesn't work
by Phil Endecott 30 Jun '08

30 Jun '08

Hi All, I've just found that if I go to http://svn.boost.org/trac/boost/ and click on the "search" link (2nd level of the indented list, "search first to avoid creating duplicates"), I get a 404. It links to http://svn.boost.org/trac/boost/trac/boost/search?ticket=on; it should be missing one of the "trac/boost"s. The search box at the top of the page does work though. (Isn't there a link checker somewhere that looks for this sort of thing?) Phil.

2 1

[serialization] Thread safety question.
by Jurko Gospodnetić 30 Jun '08

30 Jun '08

Hi. Some pages on the web (e.g. http://www.rrsd.com/boost/index.htm) and some old news posts seem to indicate that the current trunk version version to be included with Boost 1.36 makes the library 'thread safe'. What exactly does that entail? Can two separate archives be created in two separate threads? Was that not also true with the version included in the Boost 1.35 library release? Many thanks. Best regards, Jurko Gospodnetić

2 1