- Boost-users - lists.boost.org

Large boost::multi_array Problem
by Adam Hartshorne 24 Mar '06

24 Mar '06

Hi, I have the following problem, I make a boost::multi_array<float,2> of size X by X. I initialise this using the following line typedef boost::multi_array<float, 2> array_type; array_type D(boost::extents[num_vertices][num_vertices]); This works fine up to a size of 5000 x 5000 then my program crashes at the definition stage due to memory requirements. I am assuming the boost::extents call stops my program creating a multi array of a size bigger than 5000 x 5000. However in certain situations I need a bigger 2D array, any thoughts on how I can achieve this? Adam

4 4

Re: [Boost-users] [date_time] How to create a date from string withspecific format?
by Andrew Holden 24 Mar '06

24 Mar '06

> -----Original Message----- > From: Christian Henning [mailto:chhenning@gmail.com] > Sent: Tuesday, March 21, 2006 4:23 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [date_time] How to create a date from string > withspecific format? > > Hi Dean, thanks for the answer. > > Since, I know the format of the date strings I could also use > boost::regex for the general format and then feeding a date object > with the values. If I get an exception during the date object > contruction I know that the user provided me with garbage. > > > Any thoughts on that? > > Thanks again, > Christian Have you considered using Regex's submatches? A slightly modified example follows. // date format: mm-dd-yyyy boost::regex oDateReg( "(\\d{2})-(\\d{2})-(\\d{4})" ); std::string strDate( "11-33-1997" ); boost::smatch dateMatch; if( boost::regex_match( strDate , dateMatch , oDateReg )) { try { std::string strMonth = dateMatch[1]; std::string strDay = dateMatch[2]; std::string strYear = dateMatch[3]; unsigned int nYear = boost::lexical_cast<unsigned int>(strYear); unsigned int nMonth = boost::lexical_cast<unsigned int>(strMonth); unsigned int nDay = boost::lexical_cast<unsigned int>(strDay); date d( nYear, nMonth, nDay ); date::ymd_type ymd = d.year_month_day(); } catch( std::out_of_range oEx ) { std::cout << "Error: " << oEx.what() << std::endl; } } There are two advantages to this. First, you no longer need to count characters when extracting the date components. Second, you have a little more freedom in defining your date format. For example, you could use the following definition for oDateReg to also accept single-digit months and/or days: boost::regex oDateReg( "(\\d{1,2})-(\\d{1,2})-(\\d{4})" ); Andrew Holden

4 12

typecasting a boost::shared_ptr ?
by Dhanvi Kapila 24 Mar '06

24 Mar '06

Hi Friends, I have a boost::shared_ptr that stores a pointer to a base class ( class B1 ) and derived classes ( class D1 , class D2 ) both inheriting from the same Base class. The Constructors I have another set of factory classes ( base class : class base1, derived class : class derv1 & class derv2 ) whoose constructors accepts boost::shared_ptr of B1. When constructing derv1: I would like to cast pointer as D1 and ,when constructing derv2 : cast pointer as D2, but the only way I can access the class functions is through a shared_ptr to B1. My question is how do I cast B1 to get D1 and D2 in the constructors for derv1 and derv2 respectively ? the pseudo code is base1* createBase( boost::shared_ptr<B1> b_ptr , int type ) { if( type == 1 ) return new derv1( boost::polymorphic_downcast<AAAA> b_ptr ); else return new derv2( boost::polymorphic_downcast<XXXX> b_ptr ); } what do i write in the place of AAAA & XXXX for the code to wrk ?? Sorry for the long question, but could not express it in any shorter way.. thanks for ur patience and replies Dhanvi

2 1

Building multi-architecture on Mac OS X (Darwin)
by Ken Anderson 24 Mar '06

24 Mar '06

I'm trying to determine the proper command line parameters to build boost universal (i386 & ppc) on a Mac OS X machine. Can anyone give me any recommendations? I need to have this passed to the compiler and linker: -arch i386 -arch pcc Thanks, Ken

2 1

Re: [Boost-users] [iostreams] inverse and "stateful" filters
by EMalenfant＠interstarinc.com 24 Mar '06

24 Mar '06

From: EMalenfant(a)interstarinc.com > Consider the following, using dictionary_output_filter from > the tutorial: > (http://www.boost.org/libs/iostreams/doc/index.html?path=2.2.6.3) > > namespace io = boost::iostreams; > > const std::string source("This foo will be bar"); > > io::example::dictionary dict; > dict.add("foo", "bar"); > > io::filtering_istream in; > in.push(io::invert(io::example::dictionary_output_filter(dict))); > in.push(io::array_source(source.c_str(), source.length())); > > io::copy(in, std::cout); > > Output: > This bar will be > > instead of the expected: > This bar will be bar > Digging a bit, I found that I could "fix" that problem by modifying invert::read() as follows: template<typename Source> std::streamsize read(Source& src, char* s, std::streamsize n) { typedef detail::counted_array_sink<char_type> array_sink; typedef composite<filter_ref, array_sink> filtered_array_sink; assert((flags() & f_write) == 0); if (flags() == 0) { flags() = f_read; buf().set(0, 0); } filtered_array_sink snk(filter(), array_sink(s, n)); int_type status; for ( status = traits_type::good(); snk.second().count() < n && status == traits_type::good(); ) { status = buf().fill(src); buf().flush(snk); } // "Fix": When eof is reached on the input, close the filter so that it writes // any buffered input it may have. if ((snk.second().count() == 0) && (status == traits_type::eof())){ snk.close(); } //... "fix" ends here return snk.second().count() == 0 && status == traits_type::eof() ? -1 : snk.second().count(); } Looking at this, however, I wondered what would happen if the filter has buffered more characters than what would fit in the array_sink. So I tested with a very long (around 300) last word in the input. Result: An infinite loop in non_blocking_adapter::write(), desperately calling write() on a full counted_array_sink. Guess I'll forget about invert and write an InputFilter...

1 0

lexical_cast problem with OS X gcc -fast option
by Colin Dewey 23 Mar '06

23 Mar '06

If I compile the following code (test.cc): #include <iostream> #include <string> #include "boost/lexical_cast.hpp" int main() { int i; std::string s("3"); try { i = boost::lexical_cast<int>(s); } catch (boost::bad_lexical_cast& e) { std::cerr << "Error in conversion\n"; } } with the "-fast" and "-mcpu=G4" options for gcc 3.3 on MacOS X 10.4.5, like so: g++ -I. -ggdb -fast -mcpu=G4 test.cc -o test I get a Bus error when I run the compiled program. I do not get this error when I omit the "-fast -mcpu=G4" options. Here is the trace from gdb: Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_PROTECTION_FAILURE at address: 0x00000000 0x00017d44 in std::locale::operator= () at test.cc:11 11 } (gdb) backtrace #0 0x00017d44 in std::locale::operator= () at test.cc:11 #1 0x00019e54 in std::ios_base::_M_init () at test.cc:11 #2 0x0001a8c0 in std::basic_ios<char, std::char_traits<char> >::init () at test.cc:11 #3 0x0004b30c in boost::detail::lexical_stream<int, std::string>::lexical_stream (this=0xbffff6f0) at /usr/include/gcc/darwin/3.3-fast/c++/istream:98 #4 0x0004aed8 in boost::lexical_cast<int, std::string> (arg=@0xbffff9e0) at boost/lexical_cast.hpp:135 #5 0x000028e8 in main () at test.cc:10 Any help with this would be greatly appreciated. Thanks!

2 1

Newbie: Boost for Windows
by John Read 23 Mar '06

23 Mar '06

I have to work on Windows, but I don't have any idea about compilers and environments on this platform. My preference would be to use a CygWin environment with MinGW's gcc compiler to facilitate setting up a scripted nightly build incorporating Boost and my own code. Some others might want to use native Microsoft compilers and tools though. Steps so far: 1) Got/installed MinGW: MinGW-5.0.0.exe 2) Got/installed Boost: boost_1_33_1.exe 3) Opened Cygwin terminal and added MinGW/bin to path 4) cd-ed to boost_1_33_1/tools/build/jam_scr 5) . build.sh > result.txt Got these errors in results.txt: ### ### Using 'gcc' toolset. ### rm -rf bootstrap mkdir bootstrap gcc -o bootstrap/jam0 command.c compile.c execnt.c execunix.c execvms.c expand.c filent.c fileos2.c fileunix.c filevms.c glob.c hash.c hdrmacro.c headers.c jam.c jambase.c jamgram.c lists.c make.c make1.c newstr.c option.c parse.c pathunix.c pathvms.c regexp.c rules.c scan.c search.c subst.c timestamp.c variable.c modules.c strings.c filesys.c builtins.c pwd.c class.c native.c modules/set.c modules/path.c modules/regex.c modules/property-set.c modules/sequence.c modules/order.c execunix.c:19:24: sys/times.h: No such file or directory execunix.c: In function `execwait': execunix.c:187: error: storage size of 'old_time' isn't known execunix.c:187: error: storage size of 'new_time' isn't known fileunix.c:95:17: ar.h: No such file or directory fileunix.c: In function `file_archscan': fileunix.c:232: error: storage size of 'ar_hdr' isn't known fileunix.c:241: error: `SARMAG' undeclared (first use in this function) fileunix.c:241: error: (Each undeclared identifier is reported only once fileunix.c:241: error: for each function it appears in.) fileunix.c:242: error: `ARMAG' undeclared (first use in this function) I suspect that there is more involved in getting a proper Windows development environment set up. Can anyone point me in the right direction? A simple list of steps would be great. If none exists, I will provide one to the group once I have this sorted out. Thanks, John __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

2 1

Re: [Boost-users] portable uuid generator - seed
by Oliver.Kowalke＠infineon.com 23 Mar '06

23 Mar '06

Hi Andy, as you mentioned in t he source std::time(0) is not a good truly-random seed. Maybe you could use boost::posix_time::microsec_clock::universal_time().time_of_day().total_ nanoseconds() ? Regards, Oliver >hi andy, > >On Fri, 2006-03-03 at 14:26 +0000, Andy Tompkins wrote: >> I am currently working on a guid class. It is not quite done yet, but >> is quite >> functional. It does have a portable function to create guids. I have >> put it >> in the boost vault (guid.zip) in the hopes that it may one day be a >> boost >> library. > >well, the api looks really good (very similar to my libuuid wrapper) ... >but i'm a bit lost building it ... >i guess i have to run bjam, but how do i have to use it? up to now i was >just using emerging boost, but i have to experience in building it :-/ > >thanks ... tim > >-- >TimBlechmann(a)gmx.de ICQ: 96771783 >http://www.mokabar.tk > >Linux is like a wigwam: no windows, no gates, apache inside, stable.

3 2

Re: [Boost-users] asio review results - asio accepted
by RIVASSEAU Jean Noel 23 Mar '06

23 Mar '06

Thanks, actually I wrote the first message because I do not have access to the web right now, and would have liked a short explanation on the ML, but I should have explained that... I'll have a look at it this evening. Jean-Noël -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Markus Schöpflin Envoyé : jeudi 23 mars 2006 15:39 À : boost-users(a)lists.boost.org Objet : Re: [Boost-users] asio review results - asio accepted RIVASSEAU Jean Noel wrote: > Could you just explain very shortly what Asio is about ? See http://asio.sourceforge.net/ Markus _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

2 1

Re: [Boost-users] asio review results - asio accepted
by RIVASSEAU Jean Noel 23 Mar '06

23 Mar '06

Could you just explain very shortly what Asio is about ? Jean-Noël -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Jeff Garland Envoyé : jeudi 23 mars 2006 15:18 À : boost-users(a)lists.boost.org Objet : [Boost-users] asio review results - asio accepted Cross-post from development list ---- All - I'm pleased to announce that asio has been accepted into Boost. As usual with a Boost review, the asio review generated plenty of discussion, issues, and controversy. Comments ranged from high praise, including success stories of projects in production, to serious design concerns and issues. On balance, in my judgment, asio provides a generally solid library that is ready for inclusion into the Boost library -- providing key functionality in an area that developers have a strong need. Of course, like anything else, asio is not perfect -- a number of key issues were uncovered during the review. In terms of required changes I'm only going to cite a few: - Fixes to dynamic memory allocation issues - Interface changes to support ipv4 and ipv6 seamlessly at runtime - Improvements to support strongly typed socket interfaces Chris has communicated a couple possible solutions to the memory allocation issue and I'll ask that the interface and other changes for this issue continue to be discussed on the Boost list so consensus can be achieved on the best resolution. Other key improvements that should be explored as future enhancements include: - Possible removal of some of the c-style interfaces - Exploration of higher level iostream integrations - Performance improvements - Improved documentation (wouldn't be Boost w/o this one) Chris has a much longer list of changes garnered from the review and is well on his way to addressing many of them. Note that there were several threads and discussions about performance, which is particularly critical for the domain covered by asio. One of the performance issues is the dynamic memory allocation issue cited above. In general, the reviewers have extremely high expectations here. However, after reviewing the discussion and library it's my belief that many developers will find asio performance sufficient to build significant projects with only the memory allocation changes. I expect Chris will be able to address some of the other performance issues cited by reviewers in asio over time. Once again I'll apologize to the Boost community for the delay in the review results. The delay was entirely due to my own personal scheduling issues and should not reflect on asio in any way. Thanks again to all the reviewers for their effort and especially to Chris for his tremendous effort in bringing asio to Boost! Jeff _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

2 1