June 2006 - Boost-users - lists.boost.org

[python] call f(shared_ptr<const A>) with shared_ptr<A>?
by Malte Clasen 12 Jun '06

12 Jun '06

Hi, I usually use shared_ptrs to const as function parameters, such as boost::shared_ptr<const A>, to explicitly state that this function does not modify the pointee. Now I'm trying to do the same in boost.python: ----- C++ class A {}; void testA(boost::shared_ptr<A> s) {} void testAc(boost::shared_ptr<const A> s) {} void register() { class_<A, boost::shared_ptr<A> >("A") def("testA", testA); def("testAc", testAc); } void testCPP() { boost::shared_ptr<A> a(new A()); testA(a); testAc(a); } ----- Python a = A() testA(a) testAc(a) ----- The c++ part compiles and runs just fine, but the python call to testAc() fails with the following error message: ----- testAc(a) ArgumentError: Python argument types in _Map.testAc(A) did not match C++ signature: testAc(class boost::shared_ptr<class Map::A const >) ----- Is there a way to use the automatic conversion from A to const A in boost.python? Malte

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mfc applications must not include <windows.h>
by Silvester 12 Jun '06

12 Jun '06

How can i use spirit within a MFC-application? VC7.1 complains about the inclusion of <windows.h> when I include "boost/spirit.hpp" and refuses any further compilation.

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Boost compile and link problem
by Umut TABAK 12 Jun '06

12 Jun '06

Dear all, I have built boost under windows by using Cygwin and the usual configure, make, make install approach and for the gcc toolset I think this was the default one so that I have not done any configuration changes.(however i got a message that not all boost libraries are not properly installed.) I am trying to compile a very simple program to see whether things are going fine or not, (Since I have a program which is actually written under LINUX by using boost library, I have to port that to windows for a small project.) I am using the cygwin command line tool . I am supplying the include file directories for include options(-I/usr/local/include/boost-1_33_1/boost/ since I use Cygwin) but I do not know what to supply for link options(I was supplying "-L/usr/local/opt/boost-1_33_1/ lib -lboost_filesystem-gcc" under linux but did not work for windows, I have changed the path to proper values.) I have check the libboost_... under libs/ but confused me more. I am quite new to library build and compilation and linkage with the library(at least under windows since under linux pre-built packages are easily downloaded by an apt-get), maybe I am mistaken at some points above, but I appreciate advice and help. Have fun, UMUT

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[asio] ASIO Questions
by Scott 12 Jun '06

12 Jun '06

Is this the proper forum to ask about ASIO and SSL usage? Or is there another mailing list for ASIO somewhere? Thanks, Scott

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Fwd: Using numeric::ublas::matrix<...> class with NR algorithms
by Haroon Khan 12 Jun '06

12 Jun '06

Has anyone used the ublas::matrix and vector classes with the algorithms given in Numerical Recipes for C++? In other words are the ublas::matrix class and the nr::Matrix class equivalent (support the same interface) or will the algorithms require some tweaking? Haroon

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Boost under Windows
by Umut TABAK 11 Jun '06

11 Jun '06

Dear all, Can somebody provide the detailed steps to build and set up boost running under Windows for MSVC. I have used boost under Linux(Ubuntu) where the installation is just an easy apt-get there. But I could not do it under Windows. I tried the steps in the getting started guide. But I think I missed something so your help is very much appreciated. Best Regards, Umut

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[shmem-interprocess] Shmem 0.93 and update on Interprocess
by Ion Gaztañaga 10 Jun '06

10 Jun '06

Hi to all, I've just uploaded to Boost Vault a new Shmem bugfix version (0.93) with bugfixes to make Shmem MinGw friendly (props to Jan Stetka). Library and documentation download: http://boost-consulting.com/vault/index.php?&direction=0&order=&directory=M… Online documentation: http://ice.prohosting.com/newfunk/boost/libs/shmem/ //////////////////////////////////////////////////////////// Update on Interprocess: -> Due to Shmem problems with shared memory/named mutex/name semaphore lifetime between POSIX/Windows. I've decided to change Shmem approach (emulation of Windows lifetime behavior in POSIX with reference counting) to a POSIX lifetime (explicit unlinking shared memory). This means that I have to rework all main classes to achieve POSIX persistence semantics in Windows even when a process crashes. This will require using memory mapped files to emulate shared memory (with some tricks to avoid performance problems with file-memory synchronization if it's possible). I think that this approach will be much more portable than the Shmem approach. -> I'm also experimenting with a new allocator with expand-in place capabilities to allow realloc-like features in shared memory containers. The first results are encouraging both in size savings and speed improvements. This expand in place features are based on a paper I plan to present as a ISO C++ proposal based on N1953. You can find the current draft here, if you want to make some comments: http://ice.prohosting.com/newfunk/proposals/nXXXX%20Improving%20STL%20Alloc… -> I'm also experimenting with a new reduced mutex interface (basically condensing shared_mutex, shared_try_mutex and shared_timed_mutex in a single interprocess_mutex type. Something in the line of the draft "Simplifying And Extending Mutex and Scoped Lock Types For C++ Multi-Threading Library" that you can find here: http://ice.prohosting.com/newfunk/proposals/ I'm also trying to implement a process-shared version of Howard Hinnant's upgradable_mutex class described here: http://home.twcny.rr.com/hinnant/cpp_extensions/rw_perf.html http://home.twcny.rr.com/hinnant/cpp_extensions/threads_move.html I still have some bugs in my upgradable_mutex implementation that I plan to solve soon. I think that this enhazed rw mutex is a winner for Interprocess. -> I'm adding a new mutex type: file_lock. The classic UNIX fcntl / Windows FileLockEx file locking is an interesting addition to Interprocess since both in POSIX and Windows, the lock is automatically unlocked by the OS when the process ends/crashes. This can help problematic Shmem atomic creation+initialization functions if the process crashes executing the atomic code. File locking is also many times easier to use than named mutexes or shared memory + process shared mutexes, specially for simple locking. That's all. Thanks for your patience! Regards, Ion

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[Boost.Python] Extracting indirect base.
by Sebastian Redl 10 Jun '06

10 Jun '06

(No luck on C++-sig - is that list even active? There's absolutely no traffic, not one mail in two days. Anyway, trying again here.) Hi, I've got a hand-wrapped plugin interface hierarchy for my program allowing implementing plugins in Python. This looks approximately like this: class Plugin { public: virtual void init() = 0; virtual PluginCategory getCategory() = 0; // Subtype of the plugin // ... }; class InputPlugin : public Plugin { public: virtual void loadData(const string &resource, DataBag &target) = 0; }; class OutputPlugin : public Plugin { public: virtual void saveData(const string &resource, const DataBag &source) = 0; }; These are the plugin interfaces. PluginCategory is an enum identifying the concrete subtype of the plugin, i.e. either Input or Output. I've got them wrapped like this: class PluginWrap : public Plugin, public boost::python::wrapper<Plugin> { virtual void init() { this->get_override("init")(); } // ... }; class InputPlugin : public InputPlugin, public boost::python::wrapper<InputPlugin> { virtual void loadData(...) { ... } }; // ... BOOST_PYTHON_MODULE(myprogram) { class_<PluginWrap, boost::noncopyable>("Plugin") .def("init", pure_virtual(&Plugin::init)) .def( ... ) ; class_<InputPluginWrap, bases<PluginWrap>, boost::noncopyable>("InputPlugin") .def("loadData", ...) ; // ... } A plugin file looks like this: from myprogram import * class SomePlugin(InputPlugin): def init(self): // ... // ... plugins = [SomePlugin()] I then attempt to load these modules like this: PythonLoader::load(const path &file) { // Parse file and get namespace object for it. Get the "plugins" list and extract a python::list. Get the length of that list. python::list plugs = ...; int len = // get length of plugs for(int i = 0; i < len; ++i) { try { py::object plug = plugs[i]; Plugin *plugin = py::extract<Plugin *>(plug); // <------------- plugins.push_back(plugin); } catch(py::error_already_set &e) { // handle error } } } Finally, my problem: the extract<Plugin*> call fails: TypeError: No registered converter was able to extract a C++ pointer to type Plugin from this Python object of type SomePlugin So here are my questions: 1) Is this expected behaviour? Does my wrapping not register the appropriate base pointer extractors? 2) How can I manually register appropriate converters? 3) If 2 is not possible, how can I work around the problem? Thanks in advance Sebastian Redl

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BJAM : tracking dependencies
by __PPS__ 10 Jun '06

10 Jun '06

Hello ppl I have some questions about the way bjam implements dependencies tracking. I need a tool that would do this for a project that uses gcc. (it doesn't use gmake and not entire gnu toolset is available) does bjam by iteself parses all the source files, looking for incldues and then parses them to see any updates, or gcc does it? by the way I downloaded bjam sources and wanted to build it and on one machine it gave me absolutely weird results (compilation went fine, but on linking I saw some strange output with strings from registry): ... Compiling... order.c Generating Code... Microsoft (R) Incremental Linker Version 8.00.50727.42 Copyright (C) Microsoft Corporation. All rights reserved. [HKEY_CLASSES_ROOT\Directory\shell\Command Prompt Here] Settings\Temp\deleteme.r eg "@=Command &Prompt Here" Settings\Temp\deleteme.reg [HKEY_CLASSES_ROOT\Directory\shell\Command Prompt Here\command] Settings\Temp\de leteme.reg "@=cmd.exe /k cd %1 " Settings\Temp\deleteme.reg LINK : fatal error LNK1181: cannot open input file '[HKEY_CLASSES_ROOT\Directory \shell\Command.obj' C:\PAVEL\gnu_tools\tools\build\jam_src> Same shit happend with vs71

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Re: [Boost-users] Help with Tokenizer
by David Klein 09 Jun '06

09 Jun '06

boost-users-bounces(a)lists.boost.org wrote: > I have a string that is delimited with '|' that I want to > parse with boost::tokenizer. > > ie: "label 1|label2||label 3" > > It all parses ok except that the whitespace within the label > is removed. > > Is there a way to configure the tokenizer to leave whitespace alone? > > Thanks > Frank > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users hi frank, the following snippet works for me (winxp, vc71, boost 1.33.1): typedef boost::char_separator<char> separator_type; string s("label 1|label2||label 3"); boost::tokenizer<separator_type> t(s, separator_type("|")); copy(t.begin(), t.end(), ostream_iterator<string>(cout, "\n")); output: label 1 label2 label 3 HTH dave

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