Projects Penguin Icons MySQL Tools Speed up 'make' Solutions for Boost book exercises Dell Inspiron 1150 Dell Inspiron 2200 Network Monitoring SPF for Sylpheed / Claws Mail KDE EMail Settings Trium Galaxy Speed Dragon Genius GS-4500 Scanner Compatibility Konica KD-200Z Lifetec 9415 SYN Flood Protection Blocking AdWords OpenOffice HTML Export Elster durch die Firewall		My solutions to the exercises in "The Boost C++ Libraries" (free) I like books with excercises, but I also want solutions to see if I got it right. When working through The Boost C++ Libraries I only found solutions that I had to pay for, so here are my own solutions if you want to compare to yours. Please let me know if you thing I got it wrong or if you have a better solution. Chapter 2: Smart Pointers Excercise 1 #include <iostream> #include <cstring> #include <boost/shared_array.hpp> boost::shared_array<char> get(const char *s) { int size = std::strlen(s); boost::shared_array<char> text(new char[size + 1]); std::strncpy(text.get(), s, size + 1); return text; } void print(boost::shared_array<char> text) { std::cout <<text.get() <<std::endl; } int main(int argc, char *argv[]) { if (argc <2) { std::cerr <<argv[0] <<" <data>" <<std::endl; return 1; } boost::shared_array<char> text = get(argv[1]); print(text); } Excercise 2 #include <vector> #include <boost/ptr_container/ptr_vector.hpp> template <typename t> T *create() { return new T; } int main() { boost::ptr_vector<int> v; v.push_back(create<int>()); } Chapter 3: Function Objects Excercise 1 #include <algorithm> #include <functional> #include <vector> #include <iostream> #include <boost/bind.hpp> #include <boost/lambda/lambda.hpp> int divide_by(int n, int div) { return n / div; } int main() { std::vector<int> numbers; numbers.push_back(10); numbers.push_back(20); numbers.push_back(30); std::transform(numbers.begin(), numbers.end(), numbers.begin(), boost::bind(divide_by, _1, 2)); std::for_each (numbers.begin(), numbers.end(), std::cout <<boost::lambda::_1 <<"\n"); } Excercise 2 #include <string> #include <vector> #include <iostream> #include <algorithm> #include <boost/bind.hpp> #include <boost/ref.hpp> #include <boost/lambda/lambda.hpp> void save_size(std::vector<int> & sizes, const std::string & s) { sizes.push_back(s.size()); } int main() { std::vector<std::string> strings; strings.push_back("Boost"); strings.push_back("C++"); strings.push_back("Libraries"); std::vector<int> sizes; std::for_each (strings.begin(), strings.end(), boost::bind(save_size, boost::ref(sizes), _1)); std::for_each (sizes.begin(), sizes.end(), std::cout <<boost::lambda::_1 <<"\n"); } Excercise 3 #include <vector> #include <iostream> #include <cstdlib> #include <cstring> #include <boost/bind.hpp> #include <boost/function.hpp> void apply_fn(boost::function<int(const char*)> f, const char * data) { std::cout <<f(data) <<std::endl; } int main() { std::vector<boost::function<int(const char*)>> processors; processors.push_back(std::atoi); processors.push_back(std::strlen); const char data[] = "1.23"; std::for_each(processors.begin(), processors.end(), boost::bind(apply_fn, _1, data)); } Chapter 4: Event Handling Excercise 1 #include <boost/signals2.hpp> #include <iostream> class button { public: boost::signals2::connection add_handler(boost::function<void ()> h) { return handler.connect(h); } void remove_handler(boost::signals2::connection c) { c.disconnect(); } void click() { handler(); } protected: boost::signals2::signal<void ()> handler; }; void func1() { std::cout <<"Hello" <<std::endl; } void func2() { std::cout <<", world!" <<std::endl; } int main() { button btn; btn.add_handler(func1); boost::signals2::connection handle = btn.add_handler(func2); btn.click(); btn.remove_handler(handle); btn.click(); } Chapter 5: String Handling Excercise 1 #include <iostream> #include <fstream> #include <boost/regex.hpp> #include <boost/algorithm/string.hpp> int main() { std::ifstream ifs("sol.5.37.txt"); std::string xml; while(ifs.good()) { std::string line; getline(ifs, line); xml += line; } std::string first_name; std::string last_name; std::string dob_year; std::string dob_month; std::string dob_day; float amount = 0.0; std::string currency; boost::smatch what; boost::regex name_regex("<name>(.+)\\s+(\\w+)</name>"); if (boost::regex_search(xml, what, name_regex)) { first_name = what[1]; last_name = what[2]; } boost::regex dob_regex("<dob>(\\d+)\\-(\\d+)\\-(\\d+)</dob>"); if (boost::regex_search(xml, what, dob_regex)) { dob_year = what[1]; dob_month = what[2]; dob_day = what[3]; } boost::regex account_regex("<account>(.+)\\s+(\\w+)</account>"); if (boost::regex_search(xml, what, account_regex)) { std::string a = what[1]; boost::algorithm::erase_all(a, ","); amount = std::atof(a.c_str()); currency = what[2]; } else std::cout <<"no amount found in " <<xml <<std::endl; std::cout <<first_name <<" " <<last_name <<" DOB: " <<dob_day <<"." <<dob_month <<"." <<dob_year <<" : " <<floor(amount) <<" " <<currency <<std::endl; } Data <person><name>Karl-Heinz Huber</name><dob>1970-9-30</dob><account>2,900.64 USD</account></person> Excercise 2 #include <iostream> #include <fstream> #include <boost/algorithm/string.hpp> #include <boost/format.hpp> int main() { std::ifstream ifs("sol.5.38.txt"); while(ifs.good()) { std::string line; getline(ifs, line); std::vector<std::string> tok; boost::algorithm::split(tok, line, boost::algorithm::is_space()); if (tok.size() == 5) std::cout <<boost::format("%-10s -> %-10s %4.2f EUR (%05s-%05s)") % tok[0] % tok[1] % tok[2] % tok[3] % tok[4] <<std::endl; } } Data Munich Hamburg 92.12 8:25 9:45 Chapter 6: Multithreading Excercise 1 #include <boost/date_time/posix_time/posix_time.hpp> #include <boost/cstdint.hpp> #include <iostream> #include <boost/thread.hpp> boost::mutex mutex; boost::uint64_t sum = 0; void partial_sum(int from, int to) { boost::uint64_t local_sum = 0; for (int i = from; i <to; ++i) local_sum += i; mutex.lock(); sum += local_sum; mutex.unlock(); } int main() { boost::posix_time::ptime start = boost::posix_time::microsec_clock::local_time(); boost::thread t1(partial_sum, 0, 1000000000/2); boost::thread t2(partial_sum, 1000000000/2, 1000000000); t1.join(); t2.join(); boost::posix_time::ptime end = boost::posix_time::microsec_clock::local_time(); std::cout <<end - start <<std::endl; std::cout <<sum <<std::endl; } Excercise 2 #include <boost/date_time/posix_time/posix_time.hpp> #include <boost/cstdint.hpp> #include <iostream> #include <vector> #include <boost/thread.hpp> boost::mutex mutex; boost::uint64_t sum = 0; void partial_sum(int from, int to) { boost::uint64_t local_sum = 0; for (int i = from; i <to; ++i) local_sum += i; mutex.lock(); sum += local_sum; mutex.unlock(); } int main() { boost::posix_time::ptime start = boost::posix_time::microsec_clock::local_time(); std::vector<boost::thread*> threads; int num_threads = boost::thread::hardware_concurrency(); unsigned chunk = 1000000000 / num_threads; for(int i=0; i <num_threads; ++i) { boost::thread *t = new boost::thread(partial_sum, i*chunk, (i+1)*chunk); threads.push_back(t); } for(unsigned i=0; i <threads.size(); ++i) { threads[i]->join(); } boost::posix_time::ptime end = boost::posix_time::microsec_clock::local_time(); std::cout <<end - start <<std::endl; std::cout <<sum <<std::endl; } Excercise 3 #include <iostream> #include <boost/thread.hpp> boost::mutex calc_mutex; boost::mutex output_mutex; int sum = 0; void calculate() { calc_mutex.lock(); sum = 0; for (int i = 0; i <1000; ++i) sum += i; calc_mutex.unlock(); } void print() { output_mutex.lock(); std::cout <<sum <<std::endl; output_mutex.unlock(); } void thread() { calculate(); print(); } int main() { boost::thread t1(thread); boost::thread t2(thread); t1.join(); t2.join(); }