- Boost-users - lists.boost.org

[bgl] Finding the minimum cut
by Chris Jefferson 17 May '08

17 May '08

I'm looking to find the global 'vertex cut' of an undirected graph. While there are special algorithms for doing this, but I have found it can be mapped into a set of directed min-cut problems, which can be mapped into the bgl. However, it seems that while I can find the value of the max flow, I cannot find the corresponding minimum cut. Am I missing something very obvious? Chris

1 0

Windows Vista and IE7
by Van Binh 17 May '08

17 May '08

Hi all, I am writing a hooking program for Windows Vista, this program includes an EXE module and a DLL. The DLL will be mapped to every process on the desktop and it will send hooking information to the EXE module. To implement data sending I am using boost library, the EXE module creates a shared memory area and the DLL will write hooking information in this erea. This program work correctly with almost of programs excepts Windows Vista's internet explorer when it runs in protected mode. I know that this is because Windows Vista's security but I don't know how to fix it. Please help me. Thank you and best regard.

1 0

[test] assert fails - all tests passing
by Noah Roberts 17 May '08

17 May '08

This doesn't make a lot of sense to me and seems like new behavior in .35: Running 1 test case... commands: commands.cpp:5: void test_construct(): Assertion `false' failed. *** No errors detected PASS: commands ================== All 1 tests passed ================== Previously, the use of BOOST_ASSERT(xxx) was the method of testing. Is that different now? Previously, I didn't return anything from the function, I just assert. Is that different now? Boost.Test isn't listed in the updated libraries for .35 but this is definitely not the behavior I was getting in .34 Code: #include <boost/test/unit_test.hpp> void test_construct() { BOOST_ASSERT(false); } using namespace boost::unit_test; test_suite * init_unit_test_suite(int,char**) { test_suite * test = BOOST_TEST_SUITE("wumpus commands"); test->add(BOOST_TEST_CASE(&test_construct)); return test; }

5 15

Spirit and semantic action with int_p (boost 1.34.1)
by Hansi 17 May '08

17 May '08

Hello, I have a problem with a sematic action when I use int_p. I have the following declaration: array_declaration = confix_p(LEFT_BRACKET, int_p[new_int] ,RIGHT_BRACKET); and new_int is defined in the following way: typedef function< void( int ) > Int_action; Int_action new_int ( bind( &SemanticActions::new_int, &self.actions_, _1 ) ); in this case I get allways (VS2005) the error message: Error 1 error C2064: term does not evaluate to a function taking 2 arguments C:\Programme\boost\boost_1_34_1\boost\spirit\core\scanner\scanner.hpp 146 if I use instead of the Int_action a action typedef function< void( const char*, const char* ) > Str_action; I have no errors during compiling. What I make wrong? Best regards Hansjörg

3 3

Review Wizard Status Report for May 2008
by Ronald Garcia 17 May '08

17 May '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.

2 2

[serialization] Doc typo?
by Scott Howlett 16 May '08

16 May '08

Hi, In the first code example in this section: http://www.boost.org/doc/libs/1_35_0/libs/serialization/doc/serialization.h… there is the following snippet of code: // method 2 : explicitly register base/derived relationship boost::serialization::void_cast_register<derived, base>( static_cast<base *>(NULL), static_cast<derived *>(NULL) ) I believe the two arguments to void_cast_register should be swapped. (first arg is derived*, second arg is base*) Regards, Scott

2 1

using the serialization library with a std::map of Blitz++ arrays
by Ivan Gonzalez 16 May '08

16 May '08

Dear all, I have a code that uses a class which is basically a std::map of int and Blitz++ arrays. (I think that for this matter the Blitz++ array can be consider a plain array.) I need to save a bunch of these objects into a file and read them later during the same run. A typical run will produce a few thousands of these maps, each of them having a size of the order of 50, and each of these ~50 Blitz++ arrays holding a few thousands of doubles. Right now I'm just using the Blitz++ overloaded operator<<(>>) for the output (input), which pretty much runs over the Blitz++ array using the operator<<(>>) for doubles. I guess the serialization library with a binary archive would make a difference in the performance of my code. I've understood from the documentation that the serialization of STL container can be done just by including the proper header, but I must serialize the Blitz++ array by myself. Then I could use whichever Archive (binary in my case) I want to. My question is: is that the only thing I have to do to or I got it wrong? I've also seen an old thread in the mailing lists where it seemed that some people were pushing to include support for Blitz++ (and some other numerical stuff) built-in in the serialization library, has this ever been done ? More generally, would this be the best strategy to get a fast input/output for large numerical arrays or there is something else within Boost I could use ? Best, Ivan PS: I noticed that there was a tutorial on BoostCon08 on the serialization library. Is it possible to get the slides/notes?

3 4

boost-regex crashes in multithreaded
by Suresh Lakshmanan 16 May '08

16 May '08

hi, i'm using boost regex in a multithreaded environment with os: fedora 7 boost version: 1.33.1 g++: 4.1.2 i've attached a small sample program that crashes often; but not always (once in 4-5 runs) curiously, the same program runs without any issue on fedora 8, boost 1.34.1. is there any issue using boost-regex 1.33.1 in multi-threaded environment? stack trace: #0 0x00a22402 in __kernel_vsyscall () #1 0x00b921c0 in raise () from /lib/i686/nosegneg/libc.so.6 #2 0x00b93ba1 in abort () from /lib/i686/nosegneg/libc.so.6 #3 0x07fa9540 in __gnu_cxx::__verbose_terminate_handler () from /usr/lib/libstdc++.so.6 #4 0x07fa7025 in ?? () from /usr/lib/libstdc++.so.6 #5 0x07fa7062 in std::terminate () from /usr/lib/libstdc++.so.6 #6 0x07fa719a in __cxa_throw () from /usr/lib/libstdc++.so.6 #7 0x00235adb in boost::regex_error::raise () from /usr/lib/libboost_regex.so.2 #8 0x00205f1f in boost::re_detail::basic_regex_parser<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::fail () from /usr/lib/libboost_regex.so.2 #9 0x0020771f in boost::re_detail::basic_regex_parser<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::parse_repeat_range () from /usr/lib/libboost_regex.so.2 #10 0x00218c7e in boost::re_detail::basic_regex_parser<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::parse_extended () from /usr/lib/libboost_regex.so.2 #11 0x002087db in boost::re_detail::basic_regex_parser<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::parse_open_paren () from /usr/lib/libboost_regex.so.2 #12 0x00218bd6 in boost::re_detail::basic_regex_parser<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::parse_extended () from /usr/lib/libboost_regex.so.2 #13 0x002334e4 in boost::re_detail::basic_regex_parser<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::parse () from /usr/lib/libboost_regex.so.2 #14 0x002349c1 in boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::do_assign () from /usr/lib/libboost_regex.so.2 #15 0x0804babc in boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::assign () #16 0x0804bb06 in boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::assign<std::char_traits<char>, std::allocator<char> > () #17 0x0804bb42 in boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::basic_regex<std::char_traits<char>, std::allocator<char> > () #18 0x0804a2b5 in work () #19 0x0804a4e7 in thread_func () #20 0x00d0f472 in start_thread () from /lib/i686/nosegneg/libpthread.so.0 #21 0x00c3b89e in clone () from /lib/i686/nosegneg/libc.so.6 code: #include <boost/regex.hpp> #include <iostream> #include <string> #include <pthread.h> using namespace std; void work(const std::string& input, const std::string& pattern, const std::string& replace_by, const std::string& card, int thread_id) { const boost::regex search_pattern(pattern); const boost::regex card_pattern(card); std::string out = regex_replace(input, search_pattern, replace_by, boost::match_default); std::cout << thread_id << ": " << out << endl; } void* thread_func(void* id) { const string input = "0123-4567-8901-2345"; const string pattern = "1"; const string replace_by = "one"; const string card = "(\\d{3,4})[- ]?(\\d{4})[- ]?(\\d{4})[- ]?(\\d{4})"; int thread_id = (int)id; work(input, pattern, replace_by, card, thread_id); return 0; } const int MAX_THREADS = 32; int main() { pthread_t threads[MAX_THREADS]; std::list<pthread_t*> created_thread_ptrs; for (int i = 0; i < MAX_THREADS; ++i) { if (pthread_create(&(threads[i]), 0, thread_func, (void*)i) == 0) { created_thread_ptrs.push_back(&(threads[i])); } else { cerr << "Error creating thread " << i << endl; } } cerr << "Waiting for threads to terminate\n"; for (std::list<pthread_t*>::iterator it = created_thread_ptrs.begin(); it != created_thread_ptrs.end(); ++it) { pthread_join(*(*it), 0); } return 0; }

3 2

is read/write mutex example correct
by Selçuk Giray Özdamar 16 May '08

16 May '08

Hi everyone, Thanks for the prev. read/write mutex replies. I wrote a simple container which support concurrent read support and exclusive write support. Is this code correct, I havent write test code for it yet. Tnx... #pragma once #ifndef ENTITYUPDATEBUFFER_H___ #define ENTITYUPDATEBUFFER_H___ // std includes #include <vector> // boost includes #include <boost/thread/shared_mutex.hpp> template <typename T> class EntityUpdateBuffer { public: typedef typename boost::shared_lock<boost::shared_mutex> read_lock; typedef typename boost::unique_lock<boost::shared_mutex> write_lock; EntityUpdateBuffer(void){} ~EntityUpdateBuffer(void){} void push_back(const T& value); const T& at(int index) const; T& at(int index); private: std::vector<T> m_buffer; boost::shared_mutex rw_mutex; }; template <typename T> void EntityUpdateBuffer<T>::push_back( const T& value ) { // acquire lock write_lock lock(rw_mutex); m_buffer.push_back(value); } template <typename T> const T& EntityUpdateBuffer<T>::at( int index ) const { // acquire lock read_lock lock(rw_mutex); return m_buffer.at(index); } template <typename T> T& EntityUpdateBuffer<T>::at( int index ) { // acquire lock read_lock lock(rw_mutex); return m_buffer.at(index); } #endif //ENTITYUPDATEBUFFER_H___ ---Sgo---

7 9

Reg: file system
by madhukar.tiruthani＠wipro.com 16 May '08

16 May '08

Hi, I am a newbie for the boost community, I am using boost library for my file system operations. 1. Can you please tell me the way to create an empty file for a given path 2. what boost library function should I have to read data from that file. Thanks, madhu Please do not print this email unless it is absolutely necessary. The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com

4 3