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regex expression core dumps with \\
by soleani 17 Mar '02

17 Mar '02

Hi there, I've been using regex++ (v 3) for a while now. It's great! I just found out that my regex core dumps my program, look: std::string StringUtilities::getMsqlEscapedString( const char* input ) { if ( input == NULL ) return ""; cerr << "Hello" << endl; std::string inputStr( input ); cerr << "Hello111 (" << inputStr << ")" << endl; static const boost::regex expression1( "\\" ); cerr << "Hello222" << endl; string temp = boost::regex_merge( inputStr, expression1, "\\\\" ); cerr << "Hello33" << endl; static const boost::regex expression2( "'" ); return boost::regex_merge( temp, expression2, "\\'" ); } // StringUtilities::getMsqlEscapedString That's all I have. When I call it I see this: Testing getMsqlEscapedString... Hello Hello111 (hello) Aborted (core dumped) So, it seems that the call to: static const boost::regex expression1( "\\" ); makes it core dump. I went and changed that regular expression by "\"", just for kicks, and it works; it doesn't do what I want but it doesn't core dump. Anything I should do to avoid this problem? thanks, -Anibal

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Error with boost::regex library with Borland C++ Builder 6
by ynaig2k 17 Mar '02

17 Mar '02

Hi, I tried everything to understand why I get the error "Abnormal program termination" in the second run of the function with the following code: void function() { regex e( std::string(Edit1->Text.c_str()) ); cmatch what; string response; TFileStream* file = new TFileStream( "1.htm", fmOpenRead ); response.resize(file->Size+1); file->Read(response.begin(), file->Size); response[file->Size] = 0; delete file; std::string::const_iterator start; start = response.begin(); while( regex_search( start, what, e ) ) { for ( unsigned int i = 0 ; i < what.size() ; i++ ) { { std::string result = std::string(what[i].first, what[i].second); Memo1->Lines->Add( result.c_str() ); } Memo1->Lines->Add(""); start = what[0].second; } } Thanks

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Re: [Boost-Users] Re: Does filter_iterator work for maps?
by Rodrigo de Salvo Braz 16 Mar '02

16 Mar '02

-----Mensagem original----- De: Jon Kalb <kalb(a)LibertySoft.com> Para: Boost-Users(a)yahoogroups.com <Boost-Users(a)yahoogroups.com> Data: Sexta-feira, Março 15, 2002 09:01 Assunto: Re: [Boost-Users] Re: Does filter_iterator work for maps? On 3/15/02 4:37 PM, "rodrigo_braz" <rodrigo_braz(a)yahoo.com> wrote: >> Actually my main problem with this iterator is in the code below: >CodeWarrior doesn't complain about this code, but I think that it should be: As Jeremy pointed out, that doesn't work. It sounds like it is a compiler issue (I am using Borland). I will go back to the boost pages to see if there is anything I can do about it. Thanks, Rodrigo _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

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Does filter_iterator work for maps?
by rodrigo_braz 16 Mar '02

16 Mar '02

Hi, I don't see a reason for filter_iterator not to work with map iterators. However, the program below doesn't work. I get a compiler error "Cannot generate template specialization from 'make_filter_iterator<Predicate,Iterator> (Iterator,Iterator,const Predicate &)' in function main()" Any ideas? Thanks, Rodrigo #include <map> #include <ostream> #include "boost/iterator_adaptors.hpp" #include <algorithm> using namespace std; using namespace boost; struct pair_is_active { bool operator()(const pair<const size_t,float>& p) { return 0 < p.second; } }; ostream& operator<<(ostream& o, pair<const size_t, float> p) { return o << "(" << p.first << ", " << p.second << ")"; } int main() { map<size_t,float> m; m[0] = 10; m[1] = 15; m[2] = 0; m[3] = 13; copy(boost::make_filter_iterator<pair_is_active>(m.begin, m.end()), boost::make_filter_iterator<pair_is_active>(m.end(), m.end()), ostream_iterator<pair<const size_t,float> >(cout,",")); return 0; }

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boost newbie questions
by Harm de Laat 15 Mar '02

15 Mar '02

Hi all, I'm new to Boost and relativily new to C++. I'm trying to program threads on my Redhat 7.2 linux. I have the following code: #include <iostream> #include <boost/thread/thread.hpp> #include <boost/thread/xtime.hpp> struct thread_struct { thread_struct(int secs) : m_secs(secs) {} void operator ()() { boost::xtime xt; boost::xtime_get(&xt, boost::TIME_UTC); xt.sec += m_secs; boost::thread::sleep(xt); std::cout << "Boosted!!!" << std::endl; } int m_secs; }; int main (int argc, char* argv[]) { int secs = 5; std::cout << "Starting..." << std::endl; thread_struct ts(secs); boost::thread thrd(ts); thrd.join(); } The code compiles without any problems... But do I have link it against some library? Because I cannot link it to an executable file. I'm new to this. So can somebody please be so kind to help me and describe the steps nessecary to run this Thread example file... Many Thanks, Harm de Laat Informatiefabriek The Netherlands

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Error with boost::regex library in Borland C++ Builder 6
by Giany2k 14 Mar '02

14 Mar '02

Hi, Can anyone explain to me why I get "Abnormal program termination" at the exit of the function shown below in the example. The error occurs when exiting the function after it was called second time. //---------------------------------------------------------------------- ----- #include <vcl.h> #pragma hdrstop #include <boost/regex.hpp> #include <string> #include "Unit1.h" //---------------------------------------------------------------------- ----- #pragma package(smart_init) #pragma resource "*.dfm" TForm1 *Form1; //---------------------------------------------------------------------- ----- __fastcall TForm1::TForm1(TComponent* Owner) : TForm(Owner) { Edit1->Clear(); } //---------------------------------------------------------------------- ----- using namespace boost; using namespace std; void __fastcall TForm1::Button1Click(TObject *Sender) { Memo1->Clear(); if ( Edit1->Text.IsEmpty() ) return; regex e( std::string(Edit1->Text.c_str()) ); cmatch what; string response; TFileStream* file = new TFileStream( "1.htm", fmOpenRead ); response.resize(file->Size+1); file->Read(response.begin(), file->Size); response[file->Size] = 0; delete file; std::string::const_iterator start; start = response.begin(); while( regex_search( start, what, e ) ) { for ( unsigned int i = 0 ; i < what.size() ; i++ ) { std::string result = std::string(what[i].first, what[i].second); Memo1->Lines->Add( result.c_str() ); } Memo1->Lines->Add(""); start = what[0].second; } } //---------------------------------------------------------------------- -----

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Build problems on Linux with gcc 3.0.4
by Peter Simons 13 Mar '02

13 Mar '02

Hi, I have tried to build the current boost library as checked-out of the CVS repository, but I failed miserably. For one, the build process failed to recogize that Python is installed in /usr/local/python rather than /usr/local. As a result, it didn't find the python-specific include files either. I tried to set the appropriate environment variables but failed. So I added the directory /usr/local/python/include/python2.2 to CPLUS_INCLUDE_PATH and then it worked -- at least a little better than before. Once the Python includes were found, the build process progressed to actually linking some programs: gcc-Link-action status/bin/config_test.test/gcc/debug/runtime-link-dynamic/threading-multi/config_test status/bin/config_test.test/gcc/debug/runtime-link-dynamic/threading-multi/config_test.o: In function `boost_has_clock_gettime::f()': /home/simons/projects/boost-current/libs/config/test/boost_has_clock_gettime.cxx:19: undefined reference to `clock_gettime' collect2: ld returned 1 exit status Another failure was: ...failed gcc-Link-action status/bin/config_test.test/gcc/release/runtime-link-dynamic/threading-multi/config_test ... gcc-C++-action status/bin/class_concept_fail_expected.test/gcc/debug/runtime-link-dynamic/class_concept_fail_expected.o /home/simons/projects/boost-current/boost/concept_check.hpp: In member function `void boost::EqualityComparableConcept<TT>::constraints() [with TT = foo]': /home/simons/projects/boost-current/libs/concept_check/class_concept_fail_expected.cpp:25: instantiated from here /home/simons/projects/boost-current/boost/concept_check.hpp:265: no match for `foo& == foo&' operator /home/simons/projects/boost-current/boost/concept_check.hpp:266: no match for `foo& != foo&' operator Plenty of files failed to compile or to link, but I don't want to flood the list with error messages. So, first of all, is there any "right" way to tell the build process where python is installed? Maybe I should start from the scratch from there. -peter

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Jam: Building libraries that use the static runtime library
by Dale Peakall 13 Mar '02

13 Mar '02

I need to build libraries that link against the static runtime library: I tried the following Jam invocation: jam -sBOOST_ROOT=. -sTOOLS="msvc-stlport" -sBUILD="debug release <runtime-link>static" But jam balks and reports: Error: <libs!python!build>libboost_python_static: target requirements conflict for requested build { <runtime-link>dynamic <target-type>LIB <runtime-link>static } Help! So, I've obviously got it wrong (btw I'm not interested in building python library just threads and regex). TIA. - Dale.

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AIX and Boost 1.27.0 (Does not compile)
by samsrd 12 Mar '02

12 Mar '02

Has anyone tried to compile Boost 1.27.0 (or any version for that matter) on IBM AIX using the xlC compiler (IBM Visual Age). There are many compile errors (usually template related) along the lines of: "../../../../ThirdParty/boost/regex/detail/regex_cstring.hpp", line 77.40: 1540- 0152 (W) A template dependent name that is a type must be qualified with "typena me". "../../../../ThirdParty/boost/regex.hpp", line 528.55: 1540-0152 (W) A template dependent name that is a type must be qualified with "typename". "../../../../ThirdParty/boost/regex.hpp", line 532.13: 1540-1628 (S) Every templ ate parameter for a constructor template must be used in the parameter list of t he constructor. "../../../../ThirdParty/boost/regex.hpp", line 532.34: 1540-0152 (W) A template dependent name that is a type must be qualified with "typename". "../../../../ThirdParty/boost/regex.hpp", line 744.13: 1540-0152 (W) A template dependent name that is a type must be qualified with "typename". "../../../../ThirdParty/boost/regex.hpp", line 938.4: 1540-0152 (W) A template d ependent name that is a type must be qualified with "typename". "../../../../ThirdParty/boost/regex.hpp", line 438.27: 1540-0130 (S) "def_alloc_ param_traits" is not declared. "../../../../ThirdParty/boost/regex.hpp", line 1414.1: 1540-0062 (S) The incompl ete class "match_results" must not be used as a qualifier. "../../../../ThirdParty/boost/regex.hpp", line 1455.35: 1540-0140 (S) The text " &" is unexpected. "match_results" may be undeclared, ambiguous or may require " typename" qualification. "../../../../ThirdParty/boost/regex.hpp", line 444.7: 1540-1303 (I) "template cl ass match_results" is not visible. @

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thread::yield() vs Sleep()ing
by simonwlb 10 Mar '02

10 Mar '02

I'm using thread::yield() in my multi-threaded cross-platform application to avoid "CPU burn". This is because I have threads that are in an infinte loop in order to do some polling. There are no mutexes to wait on in the loop. void X::threadFunction() { for(;;) { if( m_x->isReady() ) doSomething(); . . . boost::thread::yield(); } } If the answer is "you should almost never poll like that - try to use mutexes etc. as much as possible" please say so (I'm a newbie to threads)! In any case, if I choose to have a thread in an infinite loop anyway, I have three options (assuming I have no mutexes available to me): 1. Don't yield or Sleep at all. 2. Sleep for a while - say for example, 10 ms. 3. Yield. Option 1 is clearly wrong. The CPU usage will go to 100% and the whole machine may slow down to an unusable speed. Option 2 works well in my emperical tests. The thread loop executes plenty fast enough and my Windows CPU meter shows virtually 0% CPU usage. 10ms is a bit of an arbitrary figure though - My code needs to work on a variety of software and hardware platforms, so the ideal number is hard or impossible to know. Option 3 also works well in my emperical tests and seems like the neat solution (no arbitrary waiting period). My application and the system as a whole both run smoothly and fast. The only irksome thing is that the CPU meter shows 100% usage. That's a bit alarming for me and the users of my software. My questions: 1. Should thread loops without logical wait conditions be avoided as much as possible? Is that the problem? 2. Should I just yield() or should I pause for a time period? 3. How do you select a time period to wait? Simon Bailey

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