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Using the operators library
by Sean Farrow 09 Sep '08

09 Sep '08

Hi: Can I use the operators library to override operators for the std::bitset class. If so how do I do this? Cheers Sean. __________ Information from ESET NOD32 Antivirus, version of virus signature database 3426 (20080908) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

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[multi_index_container] push_back?
by Robert Jones 09 Sep '08

09 Sep '08

Still having a little teething trouble with multi_index_container. This code, #include <string> #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/identity.hpp> #include <boost/multi_index/member.hpp> using namespace boost; using namespace boost :: multi_index; struct Employee { int id; std :: string name; }; bool operator < ( Employee const & l, Employee const & r ) { return l.id < r.id; } int main( ) { typedef multi_index_container< Employee, indexed_by< ordered_unique<identity<Employee> >, ordered_non_unique<member<Employee, std :: string, & Employee :: name> > > > EmployeeSet; Employee employees[ ] = { { 1, "Adam" }, { 2, "Craig" }, { 3, "Brian" }, { 4, "Dave" }, }; // EmployeeSet eSet( employees, employees + sizeof( employees ) / sizeof( Employee ) ); EmployeeSet eSet; std :: copy( employees, employees + sizeof( employees ) / sizeof( Employee ), std :: back_inserter( eSet ) ); return 0; } Gives me an error stating there is no push_back method on the container. /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_iterator.h:364: error: 'class boost::multi_index::multi_index_con tainer<Employee, boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::identity<Employee >, mpl_::na, mpl_::na>, boost::multi_index::ordered_non_unique<boost::multi_index::member<Employee, std::string, &Employ ee::name>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na , mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, std::allocator<Employee> >' has no member named 'push_back' is there something I'm missing out? Thanks, Rob.

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Re: [Boost-users] How the boost documentation is generated? (Peng Yu)
by Rodolfo Federico Gamarra 09 Sep '08

09 Sep '08

Hi Peng, Did you look at these webpages? http://www.boost.org/doc/libs/1_36_0/doc/html/boostbook.html http://www.boost.org/doc/libs/1_36_0/tools/quickbook/doc/html/index.html http://www.docbook.org/ Maybe you find them helpful. Thanks. -- Rodolfo Federico Gamarra

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[string algorithms] finding last digit
by Peter Barker 09 Sep '08

09 Sep '08

Hello, I have the following program: #include <string> #include <boost/algorithm/string/classification.hpp> #include <boost/algorithm/string/finder.hpp> int main() { std::string str("12.5e"); boost::last_finder(str,boost::is_digit()); // <--- is this sort of right? } What I'm trying to do is find the last occurence of a digit in my string (and learn a bit more about Boost.StringAlgorithms!). Am I going down the correct route here, and if so would someone be so kind to add to my program to show how I could obtain and output the index? The call operator for last_finder accepts two paramters which has thrown me as I thought the range was defined at construction. Thanks in advance, Pete

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[multi_index_container] Compiling the examples
by Robert Jones 09 Sep '08

09 Sep '08

Trying to multi_index_container I'm getting these compile errors. Apart from #include <string> and using namespace boost this lifted verbatim from the example documentation. #include <string> struct employee { int id; std::string name; employee(int id,const std::string& name):id(id),name(name){} bool operator<(const employee& e)const{return id<e.id;} }; #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/identity.hpp> #include <boost/multi_index/member.hpp> using namespace boost; // define a multiply indexed set with indices by id and name typedef multi_index_container< employee, indexed_by< // sort by employee::operator< ordered_unique<identity<employee> >, // sort by less<string> on name ordered_non_unique<member<employee,std::string,&employee::name> > > > employee_set; My error is multi.cpp:23: error: `indexed_by' was not declared in this scope multi.cpp:25: error: `ordered_unique' was not declared in this scope multi.cpp:25: error: `identity' was not declared in this scope multi.cpp:25: error: template argument 2 is invalid multi.cpp:25: error: expected unqualified-id before '>' token multi.cpp:25: error: expected `,' or `;' before '>' token I'm using Boost 1.36 and gcc 3.4.4 (maybe this too old?). Can anyone tell me what I'm doing wrong? Thanks, Rob. -- ACCU - Professionalism in programming - http://www.accu.org

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How the boost documentation is generated?
by Peng Yu 09 Sep '08

09 Sep '08

Hi, I'm wondering how the boost documentation for different packages is generated consistently and with code snippets extracted from the source code. Can somebody give a pointer? Thanks, Peng

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Problem with iostreams and zlib
by Alfred Kohl 09 Sep '08

09 Sep '08

Hi! the gzip_decompressor sometimes fails with Z_BUF_ERROR wrapped in zlib_error(). I'm using boost-1.36.0 and zlib-1.2.3, both statically linked. Stream setup is as follows: std::ifstream filein("testfile"); boost::iostreams::filtering_streambuf<boost::iostreams::input> strbuf; strbuf.push(boost::iostreams::gzip_decompressor()); strbuf.push(filein); std::istream input(&strbuf); do { char buf[4096]; input.read(&buf, 4096); } while (input.gcount() > 0); For one particular file, read() will fail after reading about 2 MB (of 3 MB total file size). The file decompresses fine with external tools and contains mainly zeros. The error happens in (boost/iostreams/filter/zlib.hpp): bool zlib_decompressor_impl<Alloc>::filter ( const char*& src_begin, const char* src_end, char*& dest_begin, char* dest_end, bool /* flush */ ) { before(src_begin, src_end, dest_begin, dest_end); int result = inflate(zlib::sync_flush); after(src_begin, dest_begin, false); zlib_error::check(result); // <--- return result != zlib::stream_end; } src_begin and src_end both point to the same location! I'm not an expert with zlib but this looks wrong to me... Re-compressing the file with an external tool does not help. Any ideas? Cheers, Alfred. -- GMX Kostenlose Spiele: Einfach online spielen und Spaß haben mit Pastry Passion! http://games.entertainment.gmx.net/de/entertainment/games/free/puzzle/61691…

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[boost:regex]an compiler error when use boost1_36 in application
by gj_uestc 09 Sep '08

09 Sep '08

hi,all When I use "libboost_regex-iw-mt-s-1_36.lib" in my application , I got such compiler error "cannot open file 'stlport_static.5.1.lib'".Should I need to find stlport_static.5.1.lib and add it by my self? Is there any Macro that may let myself choose whether or not use the 'stlport_static.5.1.lib'? PS:The boost lib I used is compilered with ICU,Is there any chance that the 'stlport_static.5.1.lib' is brought by useage of ICU? Thanks Juan

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Re: [Boost-users] Catching boost::thread_interrupted
by rbock＠eudoxos.de 09 Sep '08

09 Sep '08

Hi, sorry, forgot to send the attachment in the original positing... Regards, Roland Hi, currently I am making my first steps using Boost.Thread (1.36.0). The interrupt feature looks very cool, so I tried to use it, but somehow failed to catch boost::thread_interrupted. The code is attached to this mail. I was expecting to see something like Thread 0x60b050 got interrupted Thread 0x60b3e0 got interrupted Instead I got Thread 0x60b050 caught something else Thread 0x60b3e0 caught something else Can somebody please enlighten me? Thanks and regards, Roland

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[Asio] Erratic results with io_service + deadline_timer
by John Zwinck 09 Sep '08

09 Sep '08

Today I tried using Boost.Asio to make a function get called at a particular time of day. My work included some tests, which usually passed but sometimes failed. I've boiled it down below. I'm using gcc 4.0.3 and Boost 1.35 on Linux 2.6.22 (Ubuntu Dapper 32-bit i686, quad-core CPU). I compiled the following code with g++ -lboost_thread -lboost_date_time -lboost_system : #include <boost/system/error_code.hpp> #include <boost/thread/thread.hpp> #include <boost/asio/io_service.hpp> #include <boost/asio/deadline_timer.hpp> #include <boost/date_time/posix_time/posix_time.hpp> using namespace boost; using namespace boost::asio; using namespace boost::posix_time; bool g_called = false; io_service g_svc; void func(boost::system::error_code ec) { g_called = true; } void work() { for(;;) { g_svc.run(); } } int main() { thread thr(work); #ifdef FAIL // if defined, causes program to always assert this_thread::sleep(milliseconds(1)); #endif deadline_timer tmr(g_svc, second_clock::local_time() + seconds(1)); tmr.async_wait(&func); // expected to wait 1 second then call func this_thread::sleep(milliseconds(1500)); assert(g_called); } I think my first issue was that I didn't recognize the need to call io_service::run in a loop. The docs<http://www.boost.org/doc/libs/1_35_0/doc/html/boost_asio/reference/io_servi…>don't make this clear at all, stating that it will "Run the ... event processing loop," but I figured from reading the source that the loop in my own code was needed. Anyway, that didn't fix it. What I'm expecting here is that my callback function will be invoked about a second after registration, and it will set the flag which is then checked half a second later. When compiled as-is, this (usually) works. However, when compiled with -DFAIL, which just adds a tiny sleep in a place I'd think it would not matter, it fails always. Surely I'm doing something wrong. Or is the combination of this (new) library and my system just not working correctly (something I rather doubt given my past experience with Boost)?

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