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RegExp - Callback function
by Golan Trevize 27 Oct '07

27 Oct '07

Hello. First... I'm sorry for my english. And second - I've got small problem. I need use regexp. The idea is that I use 'replace', it find some text like in expression and this will be an input for function... then in function something happen and output of the function replace in text the input of the function... For example I've got text "Solution: 5 and 4". Regular expression is "[0-9]" And the function is "add5" int add5(int input){return input+5} And the output of this function replace the number with number+5... And in the end text will be: "Solution: 10 and 9" In C++ with Boost? I don't know how can I do it... something like this.... #include <cstdlib> #include <iostream> #include <boost/regex.hpp> using namespace std; using namespace boost; // the callback function string add5(string x) { int v; v =atoi(x.c_str()) + 5; string vystup = (char *)v; return vystup; } int main(int argc, char *argv[]) { string t; string k; t = "Solution: 4"; regex expression("[0-9]"); k=regex_replace(t, expression,add5, boost::match_default|boost::format_all); cout << k << endl; system("PAUSE"); return EXIT_SUCCESS; } How can I rewrite this line: k=regex_replace(t, expression,add5, boost::match_default|boost::format_all); And how I change the callback function add5... If someone know, thank you for answers and advices.

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[typeof] Duplicate definition of boost::type_of::push_back
by Dave Jenkins 27 Oct '07

27 Oct '07

Hi, I'm testing with BOOST_TYPEOF_LIMIT_SIZE greater than 50 and native typeof disabled. I get a "class template has already been defined" error on "template<class V, class T> struct push_back" whenever BOOST_TYPEOF_LIMIT_SIZE is *not* a multiple of 50. This is because push_back is defined in both "typeof/vector.hpp" and, for example, "typeof/vector50.hpp". My fix is to change the push_back definition in "typeof/vector.hpp" to: # if BOOST_TYPEOF_LIMIT_SIZE < 50 template<class V, class T> struct push_back { typedef V type; }; # endif Can someone please confirm that this is the correct fix? A tiny program demonstrating the problem is listed below. Thanks, Dave Jenkins #define BOOST_TYPEOF_COMPLIANT #define BOOST_TYPEOF_LIMIT_SIZE 51 #include <boost/typeof/typeof.hpp> int main(){ return 0; }

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[type_traits] upcoming standard question...
by Ovanes Markarian 26 Oct '07

26 Oct '07

Hello! I am just wondering, that the upcoming standard does not provide the is_rvalue type_trait. At least I did not find it in the mailings. Since there is an is_reference trait and rvalues are going to be added to the standard, don't you think the is_rvalue should be a part of upcoming standard type_traits? Many Thanks, Ovanes

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boost::serialization Qestion about versioning.
by Oleg Udovenko 26 Oct '07

26 Oct '07

Hi, As I can see from the documentation the library has only a forward compatibility. 3. Independent versioning for each class definition. That is, when a class definition changed, older files can still be imported to the new version of the class. Is there any way to achieve a backward compatibility? Thanks, Oleg.

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Boost.Test: problem with BOOST_CHECK_EQUAL for negative chars
by Mignon Belongie 26 Oct '07

26 Oct '07

The following causes a fatal error (at least for me): char c1 = -2; char c2 = -2; BOOST_CHECK_EQUAL(c1, c2); The message is: Assertion failed: (unsigned)(c + 1) <= 256 Thanks, Mignon

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boost-users [shared_array] comparing the value.
by chun ping wang 25 Oct '07

25 Oct '07

Hi I notice boost shared_array compares the pointer address not the pointer themselves. What would be the best way to compare the actual value of boost shared_array. 1.) shared_array<T> a; shared_array<T> b; 1.) return (a.len == b.len && (memcmp(a, b, len) == 0)); or 2.) if (a.len != b.len) return false; for (ptrdiff_t i = 0; i != a.len; ++i) if(a[i] != b[i]) return false; One that works ALL the times.

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Building boost::system
by Simon Pickles 25 Oct '07

25 Oct '07

Hi, Since the new update of boost::asio, I need to build boost::system. I built it using bjam in the boost/system/build directory, and it built: boost_system_vc80-gd-1_34_1.lib but my compiler needs: libboost_system-vc80-mt-gd-1_34_1.lib I'm not sure what the difference between the boost and libboost version, but I know the mt is multithreaded.... Can anyone advise? Thanks Si

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boost-1_34_1 in program_options getting compiling error : parse error before >
by Salles, Joaquim Campos 25 Oct '07

25 Oct '07

Hello, I'm using boost.1.34 and when I try to compile I get the following error: /usr/local/include/boost-1_34_1/boost/program_options/parsers.hpp:156: parse error before `>' I also try: ./configure --with-libraries=program_options Make And get the some error. What is my mistake? Thanks, Joaquim P.S. About g++ g++ -v Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/2.96/specs gcc version 2.96 20000731 (Red Hat Linux 7.3 2.96-110)

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Boost Problem
by question boost 25 Oct '07

25 Oct '07

Hi, my program makes use of Boost(Code Blocks). The arrangement of my files is the following: 1 in the directory of the source files of my program there is the directory "boost" containing the following directories: "filesystem", "config", "iterator","range","detail", "mpl", "preprocessor", "tools" and the file boost-build.jam. 2 The file that makes use of boost in my project contains the following lines: #include <string> using namespace std; #include "boost\filesystem\path.hpp" #include "boost\filesystem\operations.hpp" using namespace boost::filesystem; At compilation I get the message :"boost/preprocessor/config/config.hpp" no such file or directory and several other similar messages about other files of the same directory and about other files of the "mpl" directory. What goes wrong? Thank You David _________________________________________________________________ Découvrez le blog Messenger Le Meilleur du Web : toutes les vidéos qui buzzent le plus sur Internet ! http://meilleurduweb.spaces.live.com/

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Thread Group fails to run
by Apostolos Apostolidis 25 Oct '07

25 Oct '07

Hi all. I have developed some code allowing a thread group of 500 threads to run. However, as soon as the 381st thread is spawned, I get the following runtime error : terminate called after throwing an instance of 'boost::thread_resource_error' what(): boost::thread_resource_error The Boost documentation does not clarify the nature of the error, so I was wondering if anyone can help me out here. The (simple) program code follows. #include <boost/thread/mutex.hpp> #include <boost/thread/thread.hpp> #include <boost/bind.hpp> using namespace std; boost::mutex io_mutex; void foo(int i) { boost::mutex::scoped_lock lock(io_mutex); cout << i << endl; } int main(int argc, char *arvg[]) { boost::thread_group tg; for(int i = 0;i < 500;i++) tg.create_thread(boost::bind(&foo,i)); tg.join_all(); }

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