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[Getting Started][Build] [v2] Is it "Boost Build" or "Boost Build V2"
by Andy Little 29 May '06

29 May '06

Further helpful (I hope) criticism of the getting started Docs for boost 1.33.1 In http://www.boost.org/doc/html/bbv2/installation.html In the heading section entitled Chapter22 Installation, paragraph numbered 2. The second sentence reads: "Go to the Boost.Build root directory and run bjam --version. You should see: " etc It is too easy to assume this refers to the directory $(BOOST_ROOT)/build rather than $(BOOST_ROOT)/build/v2 and if you execute the command there you get a cryptic error message. I think what is referred to here as the Boost Build directory is referred to previously as the Boost Build V2 directory ( I feel however that it is quite likely to arrive here without having read that anyway). The physical location of v2 under the build directory can add to the confusion It might help to always refer to the directory explicitly as the Boost Build v2 directory. HTH regards Andy Little

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[regex] Strange behavior with greediness operators?
by Christopher Hart 28 May '06

28 May '06

All: I think I'm seeing strange behavior with the greediness operators in Boost.Regex (1.33.1, Mac OS 10.4.6), but was hoping someone could confirm that I'm using them correctly. For example, the following two calls: find_matches(".*a href=(.*?)>", "<html><head><title>test</title></head><body>this is a test <a href=testlink.html> more text</body></html>"); find_matches(".*a href=(.*)>", "<html><head><title>test</title></head><body>this is a test <a href=testlink.html> more text</body></html>"); Produce the same output: Expression: ".*a href=(.*?)>" Text: "<html><head><title>test</title></head><body>this is a test <a href=testlink.html> more text</body></html>" ** Match found ** Sub-Expressions: $0 = "<html><head><title>test</title></head><body>this is a test <a href=testlink.html> more text</body></html>" $1 = "testlink.html> more text</body></html" Captures: $0 = { "<html><head><title>test</title></head><body>this is a test <a href=testlink.html> more text</body></html>" } $1 = { "testlink.html> more text</body></html" } Expression: ".*a href=(.*)>" Text: "<html><head><title>test</title></head><body>this is a test <a href=testlink.html> more text</body></html>" ** Match found ** Sub-Expressions: $0 = "<html><head><title>test</title></head><body>this is a test <a href=testlink.html> more text</body></html>" $1 = "testlink.html> more text</body></html" Captures: $0 = { "<html><head><title>test</title></head><body>this is a test <a href=testlink.html> more text</body></html>" } $1 = { "testlink.html> more text</body></html" } It seems like the (.*?) expression should match only "testlink.html", as the ">" character terminates the pattern and would consume the least amount. (This same expression is working as written in Perl.) The find_matches function looks like: void find_matches(const std::string& regx, const std::string& text) { boost::regex e(regx); boost::smatch what; std::cout << "Expression: \"" << regx << "\"\n"; std::cout << "Text: \"" << text << "\"\n"; if(boost::regex_match(text, what, e, boost::match_extra | boost::match_partial)) { unsigned i, j; std::cout << "** Match found **\n Sub-Expressions:\n"; for(i = 0; i < what.size(); ++i) std::cout << " $" << i << " = \"" << what[i] << "\"\n"; std::cout << " Captures:\n"; for(i = 0; i < what.size(); ++i) { std::cout << " $" << i << " = {"; for(j = 0; j < what.captures(i).size(); ++j) { if(j) std::cout << ", "; else std::cout << " "; std::cout << "\"" << what.captures(i)[j] << "\""; } std::cout << " }\n"; } } else { std::cout << "** No Match found **\n"; } } Am I missing something in the usage, or is this a bug? Any guidance is appreciated. Thanks, Chris Hart

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[datetime] Parametrization of class datetime.
by Seweryn Habdank-Wojewódzki 26 May '06

26 May '06

Hi! I wonder if there is any posibility to change boost::datetime result class eg. long to any bignum class eg. from GMP library or double type. It is important question for calculation distance between let's say 1900 and 2100 and using method eg. total_seconds(). There is no methods like total_minutes(), total_hours(), total_days() and so on, so if I would like to have a distance in days I have to calculate distance in seconds and recalculate it to days, but for big distances total_seconds() exceeded long ranges. Regards. -- |\/\/| Seweryn Habdank-Wojewódzki `\/\/

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[lambda]lambda and lexical_cast
by Antonio Piccolboni 25 May '06

25 May '06

I just wanted to transform a vector of integers into a vecotr of strings, doesn't seem to be asking much transform(ilabels.begin(), ilabels.end(), labels.begin(), lexical_cast<string>(_1)); gcc 4.0.2 doesn't like it at all /usr/include/boost/lexical_cast.hpp:144: error: 'const class boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::bitwise_action<boost::lambda::leftshift_action>, boost::tuples::tuple<std::basic_stringstream<char, std::char_traits<char>, std::allocator<char> >&, boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >' has no member named 'fail' <begin polemic, use flame retardant> Is it only me or does lambda lack orthogonality with anything else? Whenever I use lambda for anything non isomorphic to the the plain vanilla examples, the compiler goes ballistic <end polemic> Thanks Antonio

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Re: [Boost-users] [lambda]lambda and lexical_cast
by Sohail Somani 25 May '06

25 May '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Antonio Piccolboni > <begin polemic, use flame retardant> > Is it only me or does lambda lack orthogonality with anything > else? Whenever I use lambda for anything non isomorphic to > the the plain vanilla examples, the compiler goes ballistic > <end polemic> That's why they're adding lambda functions to C++. Of course theyre not polymorphic so IMHO that makes them useless.

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boost::filesystem::filesystem_error returns wrong error code on bad path?
by Ed Johnson 25 May '06

25 May '06

Hi, When I create a bad path on purpose, the error code that boost returns is: 2 other_error, // library generated error However, the exception.hpp what() returns the string: boost::filesystem::path: invalid name "testwrite1::.txt" in path: "../data/TestFileIO/testwrite1::.txt" It seems like the string from what() correctly identifies the error at a bad path name, but it is not correctly translated in the error code enumeration. I thought it should be: 6 path_error Using boost 1.33.1 http://www.boost.org/libs/filesystem/doc/exception.htm Any thoughts? Thanks, Ed Johnson

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Google Summer of Code -- 10 Projects Assigned!
by Jeff Garland 25 May '06

25 May '06

Hi All - Just a quick note to let everyone know that Boost has been assigned 10 SOC projects! This is more than we expected and I'm hopeful will result in some great work. Even so, there are many excellent students and projects that applied for Boost projects and were NOT selected. The competition for these 10 slots was quite brutal. The choices were extremely difficult to make. It was often very hard to decide between a totally novel, high risk, project proposal and a fairly straight-forward extension to a current library. As you'll see, we ended up with some of both. The mentors have been trying to reach everyone with a notification one way or another, but it's a large list. All applicants should have heard from Google by now. If you have questions you can post to boost_soc2006(a)crystalclearsoftware.com and someone should get back to you. I'm not going to publicy share the details of the list just yet -- until we are sure all the administrative items are confirmed (google apparently accidently informed 1800 people they were accepted and then had to retract). Eventually the list should show up here: http://code.google.com/soc/boost/about.html Jeff

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[Serialization] Serializing a map
by Christian Henning 25 May '06

25 May '06

Hi there, I was just toying around with the boost serialization lib. Unfortunately I have a problem with serializing a map. Here is what I did: #include <map> #include <string> #include <iostream> #include <algorithm> #include <fstream> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/serialization/map.hpp> using namespace std; struct Settings { int Brightness; int Contrast; }; // Table indexed by strings typedef pair< string, string > Key; typedef map< Key, Settings* > Table; int _tmain(int argc, _TCHAR* argv[]) { Table aTable; aTable[ make_pair("Mueller","Meier") ] = new Settings(); aTable[ make_pair("Meier","Mueller") ] = new Settings(); aTable[ make_pair("Meier","Meier") ] = new Settings(); Settings* pSettings = aTable[ make_pair("Mueller","Meier") ]; pSettings->Brightness = 99; pSettings->Contrast = 8; ofstream ofs( "Settings.txt" ); boost::archive::text_oarchive oa( ofs ); oa << aTable; return 0; } I get an the following error: error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' .... I'm using MSVC 7.1 and boost 1.33.1 . I believe there is something very basic wrong in my code. Any help? Thanks ahead, Christian Henning

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Shmem timed mutex
by Steven Wooding 25 May '06

25 May '06

Hi, I wonder if you can help me. I'm using the Shmem library (v0.92) and I'm trying to use a shared_timed_mutex with a scoped_timed_lock. This seems to work until the mutex is about to go out of scope. Then my program just hangs. It seems that it can not unlock the mutex. I tried issuing a "unlock" function call on the lock object and that hangs as well. Could anyone confirm if the shared_timed_mutex works at the moment. Thanks for you help. Steve.

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Access violation in Boost.Format using absolute tabulations
by Edson Tadeu 25 May '06

25 May '06

If the format string have an absolute tabulation (%t), the basic_format::clear() method throws an access violation because of this piece code in format_implementation.hpp(138): if( bound_.size()==0 || !bound_[ items_[i].argN_ ] ) Here items_[i].argN_ can be negative (defined in internals.hpp(70)), which is an invalid index to bound_[]. I think a simple check of greather than zero would suffice to fix it. Here is a code that catches it: using boost::format; format f("%0s%-32.32s:%|40t|%|.6|%|55t|%25s\n"); f % "test1" % 2.0 % "test3"; f % "test4" % 5.0 % "test6"; // calls clear() and breaks

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