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[pool] Speed of pool_allocator<>
by Klaus Nowikow 01 Jul '04

01 Jul '04

Hi! I am in the process of writing a program which has to handle large numbers (~200000 - 400000) objects of the same class. These objects will be created and deleted frequently, so I thought some kind of specialized memory management would be handy. I wrote a test program (see below) to check what boost.pool would gain me. The results make me think that I have done something wrong: debug mode: std::allocator 2.17s boost::pool_allocator 7.18s release mode: std::allocator 0.11s boost::pool_allocator 0.36s i.e., std::allocator was more than 3 times faster than boost::pool_allocator (Win2k, 256MB). Any ideas what i have done wrong? See the test program below. // MemoryPoolTest.cpp // Boost includes ------------------------------------------------------------- #include <boost/timer.hpp> #include <boost/pool/pool_alloc.hpp> // Std includes --------------------------------------------------------------- #include <vector> #include <iostream> enum { NUM_ELEMENTS = 3000000 }; template <class Allocator> double Test() { std::vector<Allocator::value_type, Allocator> Vector; boost::timer Timer; for(int i = 0; i < NUM_ELEMENTS; ++i) { Vector.push_back(i); } return Timer.elapsed(); } int main(int argc, char* argv[]) { std::cout << "Starting memory pool test" << std::endl; double Time; std::cout << "Allocating with boost::pool_allocator<>: "; Time = Test<boost::pool_allocator<int> >(); std::cout << Time << "s" << std::endl; std::cout << "Allocating with std::allocator<> : "; Time = Test<std::allocator<int> >(); std::cout << Time << "s" << std::endl; return 0; }

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Newbie question... (sorry)
by Chris 30 Jun '04

30 Jun '04

Hi all, sorry for the newbie question... I have been trying to use the boost libraries with no luck I will briefly as possible list the steps I took, so that you can let me know where I went wrong. (please bear with me) 1) I downloaded the latest version and decompressed it so that i have a "C:\boost_1_31_0 directory". 2) I built Boost.Jam by starting the Visual Studio.Net command prompt, cd'ed to the "C:\boost_1_31_0\tools\build\jam_src" directory and invoked the build.bat .... The build was succesfull. 3) Copied the bjam.exe from the "C:\boost_1_31_0\tools\build\jam_src\bin.ntx86" directory to the Vc7/bin directory. 4)Added the VC71_ROOT environment variable to windows with the "C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7" path as the value. 5) Made sure that the PATH environment variable had the Vc7\bin path in it. 6) reset. 7) Started the Visual Studio.Net command prompt, cd'ed to the "C:\boost_1_31_0" directory and invoked bjam "-sTOOLS=vc7.1" install ... the whole process started.. building was succesfull (I believe) and I had a new directory c:\Boost with the \include and \lib sub dirs as mentioned in the "Getting Started" page. 8) Started visual studio.NET, went into the menu "Tools->Options->Projects->VC++ Directories" where I set "C:\boost_1_31_0" in the list of INCLUDE directories. 9) Copied a simple example from the boost website to test the libraries, compiled and VC doesn't find one of the header files.. 10) After many, many attempts I lost it and added the "C:\boost_1_31_0\lib" and "C:\boost_1_31_0\bin" to the other list of directories in the LIBRARY and EXECUTABLE list of directories in VC. After loosing it some more (after more attempts) I added even "C:\boost" in the same places as I had done in the previous steps (just in case). Now I get this fatal error "fatal error LNK1104: cannot open file 'libboost_filesystem-vc71-sgd-1_31.lib' " It doesn't seem to find the .lib but I have checked in the boost directories and that .lib is there!!! Any suggestions.... please... I also feel really bad, 'cause it seems I am the only idiot who hasn't been able to do this :(((( If someone can help me I will gladly return the favor (if I can) Thank you very very much in advance, Chris ------------------------ "Programming is Understanding" - Kristen Nygaard (I just wish I could understand more)

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[admin] Wiki Spam -- IP's are being banned
by Jeff Garland 28 Jun '04

28 Jun '04

All - I'm cross-posting this to boost-users and the developer list since it pertains to both. Over the last couple months there has been a rise in 'spam attacks' on the Wiki. Basically people are inserting links to commercial sites on wiki pages. These sites are totally unrelated to boost, c++, etc. I thank the many boosters that have spent their precious time removing the defacements. But the time has come to crack down. The following IP ranges have been banned from the Wiki. 61.55.32.* 61.55.33.* 69.63.103.* 210.82.76.* 210.82.106.* 219.233.195.* 218.5.65.* I will be monitoring and banning additional IP addresses as needed. If I have accidentally banned someone incorrectly, please let me know offlist: jeff at crystalclearsoftware.com Thanks, Jeff

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singleton_pool
by . . 28 Jun '04

28 Jun '04

hi all, i want to use singleton_pool, but on vc6.0 i get the following error (i have vc6.0 sp5): boost\pool\simple_segregated_storage.hpp(51) : error C2248: 'object_creator' : cannot access private struct declared in class 'boost::details::pool::singleton_default<struct boost::singleton_pool<class CMate rialProxy,4,struct boost::default_user_allocator_new_delete,class boost::details::pool::win32_mutex,32>::pool_type>' e:\documents\develop\include\boost-1.30.2\boost\pool\detail\singleton.hpp(63) : see declaration of 'object_creator' e:\documents\develop\include\boost-1.30.2\boost\pool\simple_segregated_storage.hpp(51) : while compiling class-template static data member 'struct boost::details::pool::singleton_default<struct boost::singleton_pool<class CMaterialProxy,4,st ruct boost::default_user_allocator_new_delete,class boost::details::pool::win32_mutex,32>::pool_type>::object_creator boost::details::pool::singleton_default<boost::singleton_pool<CMaterialProxy,4,boost::default_user_allocator_new_delete,boost::deta ils::pool::win32_mutex,32>::pool_type>::create_object' thanks in advance Fabio --------------------------------- Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages!

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ternary search trie
by Sybrand Badenhorst 28 Jun '04

28 Jun '04

Hi, Does the BOOST library (somewhere) contain a ternary search trie container type (as described by Robert Sedgewick in his "Algorithms - 3ed edition" or here: http://www.cs.princeton.edu/~rs/strings/) that can by used as a standalone container (such as for example STL's map) ? I don't find something like this listed on the Boost library page (http://www.boost.org/libs/libraries.htm) Any help will be greatly appreciated, Thanks Sybrand

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Spirit problem
by Michael Orlov 28 Jun '04

28 Jun '04

Hi, I am new to Spirit, and I am writing a reader for s-expressions, and so far has encountered the following problems, which seem to me to be contrarry to the documentation (Spirit 1.8.0 in Boost 1.31.0). Consider the following (small) C++ program: --------------------------------------------- #include <iostream> #include <iterator> #include <string> #include <boost/spirit/core.hpp> #include <boost/spirit/iterator/multi_pass.hpp> using namespace std; using namespace boost::spirit; struct Sexp : public boost::spirit::grammar<Sexp> { template <typename ScannerT> struct definition { typedef rule<ScannerT> rule; definition(const Sexp &self) { first = ( sexp = '(' >> *sexp >> ')' ); } subrule<0> sexp; rule first; const rule& start() const { return first; } }; }; int main() { typedef std::istream_iterator<char> iterator_t; typedef boost::spirit::multi_pass< iterator_t, boost::spirit::multi_pass_policies::input_iterator, boost::spirit::multi_pass_policies::first_owner > iterator_wrapper_t; Sexp sexper; iterator_t under_first(cin); iterator_t under_last; iterator_wrapper_t first(under_first); iterator_wrapper_t last(under_last); while (true) { parse_info<iterator_wrapper_t> info = parse(first, last, sexper); first.clear_queue(); if (info.hit) std::cout << "Hit: " << info.length << std::endl; else break; }; } --------------------------------------------- The purpose is to read s-expression from input, delivering them to the user the moment they are ready. Since whitespace skipper tries to consume as much space as it can, it is not suitable here, so I don't want to use it. Here comes the first problem: even when I don't pass space_p to parse(), the skipper is still present: --- ( ) ^D Hit: 2 --- --- (())( Hit: 4 ) ^D Hit: 2 --- Another problem is when I try to use istreambuf_iterator instead of istream_iterator (this is done in Spirit examples, too). When substituting istreambuf_iterator in the first typedef in main(), the program no longer compiles - neither with Intel Compiler 8.0.055, nor with GCC 3.3.2. Intel complains about /usr/local/include/boost/spirit/iterator/multi_pass.hpp(537): error: initial value of reference to non-const must be an lvalue return **input; and GCC's messages are too long to parse. :) Any help? Thanks, Michael

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Using Regex
by kinshuk srivastava 27 Jun '04

27 Jun '04

Hi I have installed the boost 1.31.0 and have been trying to compile the test examples that were there in the regular expression library.But the compiler isnt able to identify the header files.So I did include the path during my compilation by using the -I and the path name..However it is still inable to compile as it is unable to include or search the indented header files... This is my first time I have been using this kind of library.Can someone suggest a way so that I can start using the library.Is there a way in which I can directly compile nad run the files without having to go through the ordeal of specifying the path at compile time everytime I wanna use the file Any help will be highly appreciated. Sincerely -Kinshuk ________________________________________________________________________ Yahoo! India Matrimony: Find your partner online. http://yahoo.shaadi.com/india-matrimony/

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Automake/Autoconf rules for boost libs
by Sebastian Stein 27 Jun '04

27 Jun '04

Hi folks, is somewhere documented how to add automake/autoconf stuff for boost to a project? I have a set of small testcases and the need boost_unit_test_framework-gcc library to compile. At the moment I add the lib directly to linker options with project_test_LDADD = -lboost_unit_test_framework-gcc But this is not platform independent, because someone might have not gcc installed. So how can I do it in a better way? Sebastian

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[Fwd: [subgraph] unable to set graph properties using set_property() method]
by LOU Wenwu 27 Jun '04

27 Jun '04

Hi, I was trying to set graph properties, such as a meaningful name, to individual subgraphs, but the following test code failed. ====================================== typedef adjacency_list<v ecS, vecS, directedS, no_property, no_property no_property, property<graph_name_t, std::string> > graph_t; typedef subgraph<graph_t> subgraph_t; graph_t g; boost::set_property(g, graph_name, "a graph"); // **this worked, of course subgraph_t sg; boost::set_property(g, graph_name, "subgraphs"); // ** Error C2784 Error C2784: could not deduce template argument... ======================================= I used the BGL came with Boost 1.30.0 in .NET 2003. Any idea of how to make it work? Thanks, Daniel

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Newbie question: add_edge()
by Tim Rowe 27 Jun '04

27 Jun '04

Thanks for all the help so far. I'm not there yet, though! The documentation for add_edge() says that the first two parameters are of type boost::graph_traits<G>::vertex_descriptor. In the example in quick_tour.html it is called with integers (from an enum) as its first two parameters. Is that because: i. add_edge is overloaded to take integers as the first two parameters; ii. boost::graph_traits<G>::vertex_descriptor just happens to be an integer type in this case; iii. boost::graph_traits<G>::vertex_descriptor is /always/ an integer type; or iv. some other reason I haven't thought of. Thanks in advance.

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Problem
by przemyslaw.sliwa＠gazeta.pl 26 Jun '04

26 Jun '04

Dear All, I am a beginner with Boost and hae compiled the library on my suse 9.0 Athlon-m machine. I can compile the programs and link them (using Kdevelop) but if I invoke the programm I am getting a strange error which shows me that the shared library libboost_date_time-gcc-1_31.so.1. 31.0 cannot be loaded. This is somehow strange since I have linked against the static library using the argument -lboost_date_time-gcc. The boost install process compile a big rane of libraries and I am ot familar ith them. Can you help me with this issue??? Thank you very much for any kind of help, Przemyslaw

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problem compiling with Dinkumware
by Jean-Pierre Gygax 26 Jun '04

26 Jun '04

Hi, I'm having trouble properly compiling Boost with the Dinkumware STL implementation (working with Visual C++ 7.1). The problem is that bjam always calls CL with a /I that pulls in Microsoft's include files first, so that they take precedence over the Dinkumware ones. This behavior seems to be rooted far down in the file Jambase located in jam_src. I don't really feel like fooling with that. What can I do? -- Jean-Pierre

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Tweaking the Skip Parser, was RE: [Boost-users] Spirit 1.6 with VC6
by Mark Storer 26 Jun '04

26 Jun '04

> No chance of switching to 7.1? :-) Things are looking up. We just did a project-wide upgrade to... VC7.1. Problem solved. I'm now merrily writing rules for my JavaScript parser. It doesn't have to support the whole language (not for a while, maybe never), I just need to be able to parse out the names and locations of all the functions in a file. It's for a JavaScript editor built into one of our products, and later we'll be adding auto-completion. That'll require a more thorough parser, but for now, I'm just after funciton locations. So far so good... though I'll undoubtedly be quite familiar with the BOOST_SPIRIT_DEBUG* macros before I'm done. I've got another Spirit question: I've been adding "*comment" throughout the rules and it's getting tiresome: rule<phrase_scanner_t> blockComment = comment_p( "/*", "*/" ); rule<phrase_scanner_t> lineComment = comment_p( "//" ); rule<phrase_scanner_t> comment = blockComment | lineComment; Spraying the "comment" rule liberally through my rules is an option... rule<phrase_scanner_t> codeBlock = ch_p('{') >> *(comment | codeBlock | ~ch_p('}')) >> ch_p('}'); ... but not an appealing one. This becomes particularly true once I start working on the auto-completion parser. It just occured to me that if the skip parser ate comments for me, it would greatly simplify my rules. I'd like to tweak the skip parser so it skips over my "comment" rule as well as white space. I just took a stab at this, but didn't get very far. I tried: parse(str, rules, space_p | comment) but that resulted in a compiler error. 7.1's errors are MUCH easier to read that 6's. I'm going to like this new compiler. C:\SDKs\boost_1_31_0\boost\spirit\core\non_terminal\impl\rule.ipp(190): error C2664: 'boost::spirit::impl::abstract_parser<ScannerT,AttrT>::do_parse_virtual' : cannot convert parameter 1 from 'const scanner_t' to 'const boost::spirit::rule<T0>::scanner_t &' with [ ScannerT=boost::spirit::rule<boost::spirit::phrase_scanner_t>::scanner_t, AttrT=boost::spirit::rule<boost::spirit::phrase_scanner_t>::attr_t ] and [ T0=boost::spirit::phrase_scanner_t ] Pointing me to the relevant section of the docs is an acceptable answer, though I wouldn't mind a little more info than that. ;) I'll keep plugging away. If I come up with an answer, I'll post it to the list. I'd expect this to be useful to other beginners at the very least. --Mark Storer Senior Software Engineer Verity, Inc.

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RE: [Boost-users] Re: Tweaking the Skip Parser, was RE: Spirit 1.6 with VC6
by Mark Storer 25 Jun '04

25 Jun '04

Okay. Problem solved. The answer was indeed inside #scanner_business. Rules make for picky parsers. So I used a grammar<> and it compiled just fine. Now if I can just get it to WORK. ;) Whoops. Infinite recursion. Back to the drawing board... but at least now I don't need "*comment" sprinkled liberally throughout my rules. --Mark Storer Senior Software Engineer Verity, Inc. > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org]On Behalf Of Jeff Flinn > Sent: Friday, June 25, 2004 10:46 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] Re: Tweaking the Skip Parser,was RE: Spirit 1.6 > with VC6 > > > Take a look at: > > http://www.boost.org/libs/spirit/doc/faq.html#scanner_business > > You don't want the skip parser to be a phrase level scanner. > > parse(str, rules, space_p | comment_p( "/*", "*/" ) | > comment_p( "//" ) ) > > may work for you? > > Jeff F > > "Mark Storer" <MStorer(a)verity.com> wrote in message > news:076D1E704127414E9FEAFFC31F66C9472739CD@vrsdex1.verity.com... > > > No chance of switching to 7.1? :-) > > > > Things are looking up. We just did a project-wide upgrade > to... VC7.1. > Problem solved. I'm now merrily writing rules for my > JavaScript parser. It > doesn't have to support the whole language (not for a while, > maybe never), I > just need to be able to parse out the names and locations of all the > functions in a file. It's for a JavaScript editor built into > one of our > products, and later we'll be adding auto-completion. That'll > require a more > thorough parser, but for now, I'm just after funciton locations. > > > > So far so good... though I'll undoubtedly be quite familiar with the > BOOST_SPIRIT_DEBUG* macros before I'm done. > > > > I've got another Spirit question: I've been adding > "*comment" throughout > the rules and it's getting tiresome: > > > > rule<phrase_scanner_t> blockComment = comment_p( "/*", "*/" ); > > rule<phrase_scanner_t> lineComment = comment_p( "//" ); > > rule<phrase_scanner_t> comment = blockComment | lineComment; > > > > Spraying the "comment" rule liberally through my rules is > an option... > > > > rule<phrase_scanner_t> codeBlock = ch_p('{') >> > *(comment | codeBlock > | ~ch_p('}')) >> ch_p('}'); > > > > ... but not an appealing one. This becomes particularly > true once I start > working on the auto-completion parser. > > > > It just occured to me that if the skip parser ate > comments for me, it > would greatly simplify my rules. I'd like to tweak the skip > parser so it > skips over my "comment" rule as well as white space. I just > took a stab at > this, but didn't get very far. I tried: > > > > parse(str, rules, space_p | comment) > > > > but that resulted in a compiler error. 7.1's errors are > MUCH easier to > read that 6's. I'm going to like this new compiler. > > > > > C:\SDKs\boost_1_31_0\boost\spirit\core\non_terminal\impl\rule. > ipp(190): > error C2664: > 'boost::spirit::impl::abstract_parser<ScannerT,AttrT>::do_pars > e_virtual' : > cannot convert parameter 1 from 'const scanner_t' to 'const > boost::spirit::rule<T0>::scanner_t &' > > with > > [ > > > ScannerT=boost::spirit::rule<boost::spirit::phrase_scanner_t>: > :scanner_t, > > > AttrT=boost::spirit::rule<boost::spirit::phrase_scanner_t>::attr_t > > ] > > and > > [ > > T0=boost::spirit::phrase_scanner_t > > ] > > > > Pointing me to the relevant section of the docs is an > acceptable answer, > though I wouldn't mind a little more info than that. ;) > > > > I'll keep plugging away. If I come up with an answer, I'll > post it to the > list. I'd expect this to be useful to other beginners at the > very least. > > > > --Mark Storer > > Senior Software Engineer > > Verity, Inc. > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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RE: [Boost-users] Re: Tweaking the Skip Parser, was RE: Spirit 1.6 with VC6
by Mark Storer 25 Jun '04

25 Jun '04

Neither of your suggestions worked for me. Both gave me the same basic "do_parse_virtual: can't convert from 'const scanner_t' to 'const boost::spirit::rule<T0>::scanner_t &'". I had a suspision about the phrase vs char thing... good to know. So should I be looking for a compiler fix or an alternate path? Still plugging away... no joy yet. --Mark Storer Senior Software Engineer Verity, Inc. > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org]On Behalf Of Jeff Flinn > Sent: Friday, June 25, 2004 10:52 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] Re: Tweaking the Skip Parser,was RE: Spirit 1.6 > with VC6 > > > Mark, > > I didn't mean to imply this was the only way to accomplish > what you want to > do. You can create a full fledged grammar and use it as your > skip parser. > Or, create a functor_parser, which works for me. > > struct SkipperDct > { > typedef int result_t; > > template< typename ScannerT > > int operator()( ScannerT const& scan, result_t& )const > { > match<> m = ( +space_p > | lexeme_d[ comment_p("//") > | comment_nest_p("/*","*/") > ] > ).parse( scan ); > > return m? m.length() : -1; > } > }; > > functor_parser<SkipperDct> SkipperDct_p; > > }; > > Also note the use of 'comment_nest_p'. > > Jeff F > > > > "Mark Storer" <MStorer(a)verity.com> wrote in message > news:076D1E704127414E9FEAFFC31F66C9472739CD@vrsdex1.verity.com... > > > No chance of switching to 7.1? :-) > > > > Things are looking up. We just did a project-wide upgrade > to... VC7.1. > Problem solved. I'm now merrily writing rules for my > JavaScript parser. It > doesn't have to support the whole language (not for a while, > maybe never), I > just need to be able to parse out the names and locations of all the > functions in a file. It's for a JavaScript editor built into > one of our > products, and later we'll be adding auto-completion. That'll > require a more > thorough parser, but for now, I'm just after funciton locations. > > > > So far so good... though I'll undoubtedly be quite familiar with the > BOOST_SPIRIT_DEBUG* macros before I'm done. > > > > I've got another Spirit question: I've been adding > "*comment" throughout > the rules and it's getting tiresome: > > > > rule<phrase_scanner_t> blockComment = comment_p( "/*", "*/" ); > > rule<phrase_scanner_t> lineComment = comment_p( "//" ); > > rule<phrase_scanner_t> comment = blockComment | lineComment; > > > > Spraying the "comment" rule liberally through my rules is > an option... > > > > rule<phrase_scanner_t> codeBlock = ch_p('{') >> > *(comment | codeBlock > | ~ch_p('}')) >> ch_p('}'); > > > > ... but not an appealing one. This becomes particularly > true once I start > working on the auto-completion parser. > > > > It just occured to me that if the skip parser ate > comments for me, it > would greatly simplify my rules. I'd like to tweak the skip > parser so it > skips over my "comment" rule as well as white space. I just > took a stab at > this, but didn't get very far. I tried: > > > > parse(str, rules, space_p | comment) > > > > but that resulted in a compiler error. 7.1's errors are > MUCH easier to > read that 6's. I'm going to like this new compiler. > > > > > C:\SDKs\boost_1_31_0\boost\spirit\core\non_terminal\impl\rule. > ipp(190): > error C2664: > 'boost::spirit::impl::abstract_parser<ScannerT,AttrT>::do_pars > e_virtual' : > cannot convert parameter 1 from 'const scanner_t' to 'const > boost::spirit::rule<T0>::scanner_t &' > > with > > [ > > > ScannerT=boost::spirit::rule<boost::spirit::phrase_scanner_t>: > :scanner_t, > > > AttrT=boost::spirit::rule<boost::spirit::phrase_scanner_t>::attr_t > > ] > > and > > [ > > T0=boost::spirit::phrase_scanner_t > > ] > > > > Pointing me to the relevant section of the docs is an > acceptable answer, > though I wouldn't mind a little more info than that. ;) > > > > I'll keep plugging away. If I come up with an answer, I'll > post it to the > list. I'd expect this to be useful to other beginners at the > very least. > > > > --Mark Storer > > Senior Software Engineer > > Verity, Inc. > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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a template to extend types to support something like SQL NULL
by Erik Thiele 25 Jun '04

25 Jun '04

hi i have an int. but it should also support a "undefined" state like SQL NULL. most times i can use -1 for this. but there are also data types without a reasonable undefined value. maybe float or double. or maybe -1 is perfectly legal. so i used my own smartptr class (which i will replace by boost::shared_ptr since it is better and compatible to libs from strangers) to fix the problem as follows: shared_ptr<int> a(new int(10)); shared_ptr<int> b; // has the value "undefined" like SQL NULL. now i can do checks like if ( ! b ) printf("%d", *b); now my problem was that several places in my program access the same int instance. they can assign values, and then other parts of the program can read these values. that's good behaviour.but i cannot set the object to "undefined". see why: void foo (shared_ptr<int> a) { *a = 10; // <-- ok! this works! everybody now has the 10! } void errorfoo (shared_ptr<int> a) { a.reset(); // <-- this does of course not work, since only my local // copy of a is now SQL NULL. } so i restructured my shared_ptr to make it able to hold this special SQL NULL state also. this way i got really awkward semantics though. i don't go in details here, but in my shared_ptr the errorfoo function works as expected. (the function is not called "reset" then). but i got severe problems in typecast semantics of my modified shared_ptr, so i decided to dump this beast before anyone else has to see it :-))) i thought that maybe it's not a good idea to unite smartpointer with SQL NULL facility. maybe it is better to write: shared_ptr<nullabletype<int> > x(new nullabletype<int>(55)); x->setnull(); if (x->isnull()) fooooo(); printf("the int is %d\n", x->obj()); // throw exception if x is null in this example the shared_ptr is just sugar. it is not needed. the nullable subsystem is now independent from shared_ptr. is there such a nullable type extender beast in boost somewhere? or do i have to invent it? by the way, the following is not a good solution i think: int thevalue; bool thevalue_is_defined; now programmers can do errors like access "thevalue" even though "thevalue_is_defined" is false. i want some mechanism to prevent programmers from doing this kind of errors. if and only if the value is defined it should be possible to read it. also this nullable type extender is handy for a database layer to interact with SQL. cya! erik -- Erik Thiele

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OT: detect unneded includes
by Erik Thiele 25 Jun '04

25 Jun '04

hi. this is OFFTOPIC. i am searching for a way to detect unused #include directives. i'd appreciate some GPL tool. in the transition from more and more of my own small helper classes to boost stuff i find difficult to remove unneeded #includes. i am sure my code is full of useless dependencies. cya erik -- Erik Thiele

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Spirit 1.6 with VC6
by Mark Storer 25 Jun '04

25 Jun '04

I'm getting several compiler errors when trying to use the Spirit library. When compiling one of the samples from the v1.6 documentation, I get a linker error: SpiritTest.obj : fatal error LNK1179: invalid or corrupt file: duplicate comdat "?do_parse@?$parse_subrule@V?$match@Unil_t@spirit@boost@@@spirit@boost@@U?$subrules_scanner@V?$scanner@PBDU?$scanner_policies@U?$skipper_iteration_policy@Uiteration_policy@spirit@boost@@@spirit@boost@@Umatch_policy@23@Uaction_policy@23@@spirit@boos67ac75e0" LNK1179 suggested that the /H _compiler_ option might be involved. It (supposedly) controls how long a symbol is allowed to be when the compiler is generating symbol names. I've tried several different variations on the /H option, /H512, /H1024, etc. They all give the same error message, and the symbol "?do_parse@..." doesn't get any longer (or shorter for that matter). I also get a number compiler errors when I #include <boost/spirit.hpp>: c:\sdks\boost-1.30.2\boost\spirit\utility\impl\chset\basic_chset.ipp(32) : error C2955: 'arg' : use of class template requires template argument list c:\sdks\boost-1.30.2\boost\bind\arg.hpp(26) : see declaration of 'arg' ----------basic_chset.ipp, lines 31-33 template <typename CharT> inline basic_chset<CharT>::basic_chset(basic_chset const& arg) : rr(arg.rr) {} ----------arg.hpp lines 24-26 template<int I> class arg { }; The boost/bind include is in the core/composite/actions. Trying to mess with the order of inclusion seems Fraught With Peril. The basic_chset template is in "utility", and everything in "utility" depends on various bits and pieces of "core". basic_chset is derived from unary, which is defined in core/composite. A Gordian knot... and me without a sword. --Mark Storer Senior Software Engineer Verity, Inc.

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RE: [Boost-users] protassign
by Nat Goodspeed 24 Jun '04

24 Jun '04

> -----Original Message----- > From: Nat Goodspeed > Sent: Wednesday, June 23, 2004 12:17 PM > To: boost-users(a)lists.boost.org > Subject: RE: [Boost-users] protassign > > In the forthcoming Boost serialization library: > > http://www.rrsd.com/boost/ > > there's a state_saver template class that does what you're talking > about: > > http://www.rrsd.com/boost/libs/serialization/doc/state_saver.html > > This seems useful enough to promote to a library more general than the > serialization library. Hmm! I was suggesting that the state_saver template from the serialization library be elevated. If the protassign template makes it into Boost sooner, may I suggest that the serialization library be revised to use protassign instead of state_saver? We certainly wouldn't want two redundant Boost templates.

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RE: [Boost-users] protassign
by Nat Goodspeed 24 Jun '04

24 Jun '04

> -----Original Message----- > From: Erik Thiele [mailto:erik@thiele-hydraulik.de] > Sent: Wednesday, June 23, 2004 11:28 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] protassign > > now i can do: > > void foo() > { > protassign<bool> foorunning_assigner(foorunning, true); > dojobs(); > dofoooo(); > } > > and that's all. is there one such thing in boost already??? [Nat] In the forthcoming Boost serialization library: http://www.rrsd.com/boost/ there's a state_saver template class that does what you're talking about: http://www.rrsd.com/boost/libs/serialization/doc/state_saver.html This seems useful enough to promote to a library more general than the serialization library.

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failures and featurerequest in/for numeric_cast
by Peter Piehler 24 Jun '04

24 Jun '04

failures and featurerequest in/for numeric_cast I use boost in a little project for my study. In some cases the software must convert numeric datatypes. So I tried to convert with boost-library numeric_cast and found the following problems (gcc version 3.2.3 20030422): -the maximum could not be handled correctly, for example: +numeric_cast<int>(numeric_limits<unsigned int>::max()); doesn't throw a exception -no precession handling, example: +numeric_cast<float>(numric_limits<double>::epsilon()+1); doesn't throw a exception -no NaN, bounded/unbounded and exact handling. -no specialization. I need numeric_cast specializiation for: +numeric_limits-interface can't use for datatypes with caracteristics only known at runtime. +datatyps without static_cast support (example: gmp-library) So I have extended the boost::numeric_cast for my special requirements. You can download it under the following link: http://www.pienet.de/source/numeric_cast.tar.gz . Compile and run numeric_cast_tescases.cpp with USE_BOOST_CAST to test ::boost::numeric_cast. The output is: Running 2 test cases... numeric_cast_testcases.cpp(72): error in "standard_cast_test": exception bad_numeric_cast is expected numeric_cast_testcases.cpp(91): error in "standard_cast_test": exception bad_numeric_cast is expected numeric_cast_testcases.cpp(93): error in "standard_cast_test": exception bad_numeric_cast is expected numeric_cast_testcases.cpp(135): error in "standard_cast_test": exception bad_numeric_cast is expected *** 4 failures detected in test suite "numeric_cast Test" I think the line static_cast<X>(static_cast<Y>(x)) != x; is a tricky code. For X/Y==char/unsigned char,short/unsigned short etc. is always false. The compiler convert it only if the datatypes have not the same size/bytes or are between integers and floating points. sorry for my bad english and code, it's the first time that i ever have published. Peter Bestellen Sie Y! DSL und erhalten Sie die AVM "FritzBox SL" für 0. Sie sparen 119 und bekommen 2 Monate Grundgebührbefreiung. http://de.adsl.yahoo.com

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bug in date_time? cannot initialize ptime to not_a_date_time
by Erik Thiele 24 Jun '04

24 Jun '04

hi. #include <boost/date_time/posix_time/ptime.hpp> int main() { boost::posix_time::ptime x(boost::date_time::not_a_date_time); } # g++ --version 2.95.4 #g++ -Wall -c foo.cpp -Iboost_1_31_0 (compiling into cache) foo.cpp: In function `int main()': foo.cpp:5: no matching function for call to `boost::posix_time::ptime::ptime (boost::date_time::special_values)' boost/boost/date_time/posix_time/ptime.hpp:39: candidates are: boost::posix_time::ptime::ptime(boost::gregorian::date, boost::posix_time::time_duration) boost/boost/date_time/posix_time/ptime.hpp:42: boost::posix_time::ptime::ptime(boost::gregorian::date) boost/boost/date_time/posix_time/ptime.hpp:45: boost::posix_time::ptime::ptime(const boost::posix_time::int64_time_rep &) boost/boost/date_time/posix_time/ptime.hpp:48: boost::posix_time::ptime::ptime(const boost::posix_time::ptime &) foo.cpp:5: warning: unused variable `class boost::posix_time::ptime x' -- Erik Thiele

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protassign
by Erik Thiele 23 Jun '04

23 Jun '04

hi in some cases i do assign values to variables just for the life of my function: void foo() { bool oldfoorunning = foorunning; foorunning = true; dojobs(); dofoooo(); foorunning = oldfoorunning; } now the problem arises when dojobs throws an exception. in order to be safe i have to do: void foo() { bool oldfoorunning = foorunning; foorunning = true; try { dojobs(); dofoooo(); } catch (...) { foorunning = oldfoorunning; throw; } foorunning = oldfoorunning; } this is ugly and it can get more ugly by having more than one such variable. then you stack try/catch into each other and code gets really ugly and error prone. for that reason i created a class as follows: template<class X> class protassign : public boost::non_copyable { public: inline protassign (X &var_, const X &newvalue) : var(var_) { oldvalue = var; var = newvalue; } inline ~protassign () { try { var = oldvalue; } CATCHDESTRUCTOR; //<-- my special destructor error catching macro, //forget it. (is there an alternative in boost?) } private: X &var; X oldvalue; }; now i can do: void foo() { protassign<bool> foorunning_assigner(foorunning, true); dojobs(); dofoooo(); } and that's all. is there one such thing in boost already??? cu erik -- Erik Thiele

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Re: Re: compiling boost with mingw in winxp
by Alexis H. Rivera-Rios 23 Jun '04

23 Jun '04

Hi, 1) g++ is in the path. Doing the g++ --version displays the version information: C:\opt\boost_1_31_0>g++ --version g++ (GCC) 3.2.3 (mingw special 20030504-1) Copyright (C) 2002 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 2) Mingw is installed in the default directory: c:\mingw Does the fact that I got a warning about spawnvp function when I built bjam has something to do with this? C:\opt\boost-jam-3.1.10>.\bootstrap.mingw\jam0 -f build.jam --toolset=mingw "--t oolset-root= " ...found 83 targets... ...updating 4 targets... .cc. bin.ntx86\yyacc.exe .cc. bin.ntx86\mkjambase.exe .cc. bin.ntx86\jam.exe execnt.c: In function `execcmd': execnt.c:651: warning: passing arg 3 of `spawnvp' from incompatible pointer type execnt.c:682: warning: passing arg 3 of `spawnvp' from incompatible pointer type .link. bin.ntx86\bjam.exe 1 file(s) copied. ...updated 4 targets... I read somewhere something about different signatures for the spawn function and this indicates the one used by bjam is not the one that mingw supports. Why would spawn fail? Is this an OS issue or a compiler thing? Is bjam the program that fails? Or is it a python script that fails? How can I trace this error? I really appreciate your help, Alex ===== Programming Tutorial: In Python: To do this, do this In Perl: To do this, do this or this or this or this... In C: To do this, do this, but be careful In C++: To do this, do this, but don't do this, be careful of this, watch out for this, and whatever you do, don't do this __________________________________ Do you Yahoo!? Yahoo! Mail - 50x more storage than other providers! http://promotions.yahoo.com/new_mail

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Re: [Boost-users] Re: compiling boost with mingw in winxp
by Alexis H. Rivera-Rios 22 Jun '04

22 Jun '04

Hi, This is the output of running the command line with the d+4 and d+2 option respectively. I'm running the command from the dos shell (cmd.exe). As far as the filesystem. The filesystem is NTFS. Thanks, Alex C:\opt\boost_1_31_0>bjam -sTOOLS=mingw -sPYTHON_ROOT=c:\Python23 -sPYTHON_VERSIO N=2.3 -d+4 Executing raw command directly Executing command [g++] [-Wl,--exclude-symbols,_bss_end__:_bss_start__:_data_end __:_data_start__] [-Wl,--out-implib,bin\boost\libs\date_time\build\boost_date_ti me.dll\mingw\debug\boost_date_time-mgw-d-1_31.lib] [-g] [-shared] [-mno-cygwin] [-o] ["bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\boost_date _time-mgw-d-1_31.dll"] ["bin\boost\libs\date_time\build\boost_date_time.dll\ming w\debug\greg_month.obj"] ["bin\boost\libs\date_time\build\boost_date_time.dll\mi ngw\debug\greg_weekday.obj"] ["bin\boost\libs\date_time\build\boost_date_time.dl l\mingw\debug\date_generators.obj"] spawn: Invalid argument C:\opt\boost_1_31_0>bjam -sTOOLS=mingw -sPYTHON_ROOT=c:\Python23 -sPYTHON_VERSIO N=2.3 -d+2 gcc-Link-action bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\b oost_date_time-mgw-d-1_31.dll bin\boost\libs\date_time\build\boost_date_time.dll \mingw\debug\boost_date_time-mgw-d-1_31.lib g++ -Wl,--exclude-symbols,_bss_end__:_bss_start__:_data_end__:_data_start_ _ -Wl,--out-implib,bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debu g\boost_date_time-mgw-d-1_31.lib -g -shared -mno-cygwin -o "bin\boost\libs\dat e_time\build\boost_date_time.dll\mingw\debug\boost_date_time-mgw-d-1_31.dll" "bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\greg_month.obj" "bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\greg_weekday.obj " "bin\boost\libs\date_time\build\boost_date_time.dll\mingw\debug\date_generator s.obj" spawn: Invalid argument ===== Programming Tutorial: In Python: To do this, do this In Perl: To do this, do this or this or this or this... In C: To do this, do this, but be careful In C++: To do this, do this, but don't do this, be careful of this, watch out for this, and whatever you do, don't do this __________________________________ Do you Yahoo!? Yahoo! Mail - 50x more storage than other providers! http://promotions.yahoo.com/new_mail

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