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Idea for equation library
by Stephen Gross 04 Apr '06

04 Apr '06

I've got an idea for a toolkit that uses boost::lambda to let you write 'equations' on the fly in c++. For instance, consider the following pseudo-code: ================== Equation e = x + y; print e(x -> 5, y -> 10) // Prints 15 e = x - y print e(x -> 5, y -> 10) // Prints -5 Equation d = eq(e) + z print d(x -> 1, y -> 2, z -> 3) // Prints 2 ================== The idea is that you can encapsulate an algebraic function in a standalone 'Equation' instance, and dynamically reassign that equation. It's built off of boost::lambda (of course), but it lets you name the variables rather than just refer to them with the standard placeholders (_1, _2, etc.). Is it worthwhile for me to post the toolkit code on this group? Thanks, --Steve Stephen Gross Case Western School of Medicine Cleveland, OH "By Grabthar's hammer, by the sons of Worvan, you shall be avenged." - Dr. Lazarus

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using random library
by Kamil Renczewski 04 Apr '06

04 Apr '06

Hello I have a problem. I need to write program, whitch interprets arguments given at runtime and create generators from this arguments. Then i have to use this generators (by calling operator() method) to generate numbers. Problem is that i dont know type of generators at compile time and i dont know how to store them in struct or class or even pass to a function. Here is en example of my thinking: i run program like this: generators N 10 2 E 2.3 and i would like to get some ramdom numbers from a normal_distribution<>(10, 2) and exponential_distribution<>(2.3) another run of a program might be: generators U -10 30 G 0.3 whitch should give me an uniform_int<>(-10, 30) and geometric_distribution<>(0.3) . Any ideas how to do this? thanks

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Building 1.33.1 with Sun Studio 11
by paul.floyd 04 Apr '06

04 Apr '06

Hi all I've almost managed to get Boost 1.33.1 to build on Solaris with Sun Studio 11. I'm not quite up to speed yet with all of the Boost MACROS (in particular the WORKAROUND one). Here's what I've done so far: a) Apply all of the latest patches to Sun Studio 11 b) Apply all of the patches at http://blogs.sun.com/roller/page/sga?catname=%2FBoost c) I had a compile problem with readdir_r not being seen. To fix this I changed my bjam command line to add -sSUNPRO_CXX="CC -D_XOPEN_SOURCE=500" (on Solaris 10 you may prefer -D_XOPEN_SOURCE=600) d) In boost/test/impl/unit_test_suite.ipp, the code makes use of std::random_shuffle. AFAICS this uses rand48(), and rand48() is in <stdlib.h> but not in <cstdlib> and std::. To fix this I added #if defined(__SUNPRO_CC) #include <stdlib.h> #endif at line 42. (this looks like a compiler/std lib issue to me) e) I had some errors with size_t not being in the global scope (Sun Studio is the pickiest compiler I know of for this). This comes from boost/config/posix_features.hpp including unistd.h My fix for this was to add #include <cstdlib> using std::size_t; at line 17 of boost/config/platform/solaris.hpp f) I had two problems with libs/iostreams/src/bzip2.cpp f.1) bzlib.h uses FILE as if it were in the global scope, but as per point e), with Sun Studio, when including <cstdio>, it is in std::, so just before including "bzip2.h" (line 18) I added #include <boost/iostreams/filter/bzip2.hpp> #if defined(__SUNPRO_CC) using std::FILE; #endif f.2) Solaris 8 ships with a version of libbz2 that is too old to be compatible with the Boost.Iostreams code. Iostreams doesn't seem to do any checking of the libbz2 version (if any version is available to check). To fix this I downloaded libbz2 from http://www.bzip.org/downloads.html, untarred it to a '3rdparty' directory, built it (make CC=cc CFLAGS=-xO5) and then changed my bjam command line to use -sSUNPRO_CXX="CC -D_XOPEN_SOURCE=500 -I/home/paulf/scratch/boost_1_33_1/3rdparty/bzip2-1.0.3" This leaves me with (for the moment) one compile error: boost/spirit/core/non_terminal/impl/grammar.ipp, line 279 the compiler complains about Error: Initializing definition_t &def = get_definition<DerivedT, ContextT, ScannerT>(self); requires an lvalue At first I thought this might be related to Sun Studio having an issue with name mangling typedefs, but this doesn't seem to be the case. A+ Paul Accédez au courrier électronique de La Poste : www.laposte.net ; 3615 LAPOSTENET (0,34 /mn) ; tél : 08 92 68 13 50 (0,34/mn)

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Re: [Boost-users] Perl Regex Question
by paul.floyd 04 Apr '06

04 Apr '06

> admin(a)geocodenet.com wrote : > > > When I use this regular expression: > > > > ^(*.)a(*.) [snip] > > 1==>M > > 2==>nagement > > This is what you get if you use (.*?) (ungreedy) Or alternatively (and more portable to different regex engines which may not have non-greedy options): ^([^a]*)a(.*) A+ Paul Accédez au courrier électronique de La Poste : www.laposte.net ; 3615 LAPOSTENET (0,34 /mn) ; tél : 08 92 68 13 50 (0,34/mn)

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Confusion on The Directory Structure For serialization library
by Cheok Yan Cheng 04 Apr '06

04 Apr '06

Hello all, I just download boost 1.33.1 and I am building using VC++ 7.1. I am a bit confused on the directory structure of serialization library (1) \bin\boost\libs\serialization\build\libboost_serialization.lib \bin\boost\libs\serialization\build\libboost_wserialization.lib May I know the differences among libboost_serialization.lib and libboost_wserialization.lib directory? What is the meaning of 'w'? (2) \bin\boost\libs\serialization\build\libboost_serialization.lib \bin\boost\libs\serialization\build\boost_serialization.dll First, I thought libboost_serialization.lib are mean for static library, boost_serialization.dll are mean for dynamic library. However, inside the libboost_serialization.lib directory, they are further divided into libboost_serialization.lib\vc-7_1\release\runtime-link-static\threading-multi libboost_serialization.lib\vc-7_1\release\threading-multi <---- (Does this mean this is a dynamic library since it doesn't contains runtime-link-static??? How about boost_serialization.dll) Thank you very much! __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: [Boost-users] [multi_index] Serialization problemwithmulti_indexcontainer
by JOAQUIN LOPEZ MU?Z 04 Apr '06

04 Apr '06

----- Mensaje original ----- De: John Reid <john.reid(a)wibr.ucl.ac.uk> Fecha: Lunes, Abril 3, 2006 5:09 pm Asunto: Re: [Boost-users] [multi_index] Serialization problemwithmulti_indexcontainer > Joaquín Mª López Muñoz wrote: > > What this means is, if you've got elements a,b and its corresponding > > deserialized equivalents a',b', then a<b must yield the same value > > (true or false) as a'<b' --assuming it is operator< that is used > for sorting > > the index, which is the case if identity<element> is the key and > > the default sorting criterion is used. > > Ok thanks, that makes sense. I should have read that. > > My value_type has a data member that is a pointer to an object of > an > abstract class. I would like one index to be sorted by the > addresses of these objects. Yep, here's the problem, addresses' order is not preserved. > There seems no way to do this and have direct > serialisation of the multi_index container. Can you confirm? Yes, I'm afraid you can't directly serialize a multi-index container one of whose indices is of type ordered_non_unique and the key is the address of some mmember (or the whole element.) You'll have to stick to your current workaround --but you can improve it a bit: you don't really need to use an intermediate vector if you do the serialization process "by hand": save: save the number of elements. traverse the first index and save he visited elements. load: clear the container. load the number of elements N. repeat N times: load an element and insert it into the container. The overall effect is the same as with the intermediate vector, without any extra overhead. > Maybe I'm > missing something. Is there a reason why the serialisation > implementation does not recalculate the indices on the fly? Well, this is prewisely what's happening. Consider the following: struct element { element(int x,int y,int z):x(x),y(y),z(z){} int x,y,z; }; typedef multi_index_container< element, indexed_by< ordered_non_unique<member<element,int,&element::x> >, ordered_non_unique<member<element,int,&element::y> > > > multi_index_t; multi_index t m; element a(0,1,0); element b(1,1,1); element b(2,1,2); m.get<1>()insert(a); m.get<1>().insert(b,m.get<1>().begin()); m.get<1>().insert(c,m.get<1>().begin()); Now, if you traverse m by its index #0, the result is (0,1,0), (1,1,1), (2,1,2) whereas if you traverse it by index #1, the order is, because of our use of hinted insertion, the following: (0,1,0), (2,1,2), (1,1,1) So far so good. When saving and subsequently loading this container, Boost.MultiIndex guarantees that the traversal order of *every* index is preserved. Now, suppose serialization were implemented the naive way, that is, by just saving the elements as they are visited by the first index and loading through the first index again, just as you're doing in your workaround (no offense meant by the use of the word "naive", of course.) If you examine the process carefully, you can see that, when performed this way, index #0 is correctly replicated, but the resulting order of the loaded index #1 is (0,1,0), (1,1,1), (2,1,2) which does not match the original. This is why Boost.MultiIndex saves, additionally to the elements, enough extra information to restore index traversal orders in those cases where such order is not univocally determined (ordered non-unique, sequenced and random-access indices.) And when applying this extra information, the kind of sanity check you've been bitten by is routinely performed. I hope I've made myself clear, sorry for the long explanation. > Thanks for your response, > John. Thank you for using Boost.MultiIndex. I'm sorry out-of-the-shelf serialization capabilities can't serve your particular needs. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Linker errors with boost::regex with boost_1_33_1, STLport-4.6.2 and VS7.1
by Vijay Choudhary 04 Apr '06

04 Apr '06

Hi All, Is there a known issue of linker errors with using boost::regex library with STLport. If I don't install STLport I am able to build regex however I am getting linker error while trying to build after installing STLPort. Operating System:Win-XP IDE: Visual Studio .NET(version 7.1.3088) STLPort version: STLport-4.6.2 Boost versio:boost_1_33_1 The code which I have used in sample project: #include "stdafx.h" #include <boost/regex.hpp> #include <iostream> #include <string> int _tmain(int argc, _TCHAR* argv[]) { std::string line; boost::regex pat( "^Subject: (Re: |Aw: )*(.*)" ); while (std::cin) { std::getline(std::cin, line); boost::smatch matches; if (boost::regex_match(line, matches, pat)) std::cout << matches[2]; } return 0; } I got following linker errors: ConsoleApp1.obj : error LNK2019: unresolved external symbol "void __cdecl boost::re_detail::raise_runtime_error(class _STL::runtime_error const &)" (?raise_runtime_error@re_detail@boost@@YAXABVruntime_error@_STL@@@Z) referenced in function "void __cdecl boost::re_detail::raise_error<struct boost::regex_traits_wrapper<struct boost::regex_traits<char,class boost::w32_regex_traits<char> > > >(struct boost::regex_traits_wrapper<struct boost::regex_traits<char,class boost::w32_regex_traits<char> > > const &,enum boost::regex_constants::error_type)" (??$raise_error@U?$regex_traits_wrapper@U?$regex_traits@DV?$w32_regex_tr aits@D@boost@@@boost@@@boost@@@re_detail@boost@@YAXABU?$regex_traits_wra pper@U?$regex_traits@DV?$w32_regex_traits@D@boost@@@boost@@@1@W4error_ty pe@regex_constants@1@@Z) ConsoleApp1.obj : error LNK2019: unresolved external symbol "class _STL::basic_string<char,class _STL::char_traits<char>,class _STL::allocator<char> > __cdecl boost::re_detail::w32_transform(unsigned long,char const *,char const *)" (?w32_transform@re_detail@boost@@YA?AV?$basic_string@DV?$char_traits@D@_ STL@@V?$allocator@D@2@@_STL@@KPBD0@Z) referenced in function "public: class _STL::basic_string<char,class _STL::char_traits<char>,class _STL::allocator<char> > __thiscall boost::w32_regex_traits<char>::transform(char const *,char const *)const " (?transform@?$w32_regex_traits@D@boost@@QBE?AV?$basic_string@DV?$char_tr aits@D@_STL@@V?$allocator@D@2@@_STL@@PBD0@Z) Debug/ConsoleApp1.exe : fatal error LNK1120: 2 unresolved externals However if I comment call to function boost::regex_match() in sample code , then I am able to build it. Regards: Vijay Kumar

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does ptr_* solves this?
by Marco Correia 04 Apr '06

04 Apr '06

Hi, I have an heterogeneous container holding pointers to objects of type B. I want to insert objects of type D1,D2,... that derive from B, and I want to do that using a custom stl like allocator, for example: B* obj = my_alloc<D>::allocate(1); obj = new (obj) B(); container.insert(obj); My problem is that when an object is removed from the container, I have to explicitely deallocate it from my allocator, but the static info was lost, so I cannot do my_alloc<?>::deallocate(1,oj); I've asked in boost irc channel, and someone told me ptr_* boost libraries solve this problem, is this correct? thanks -- Marco Correia <mvc(a)netcabo.pt>

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[BGL] GraphML ?
by Tiago de Paula Peixoto 04 Apr '06

04 Apr '06

Hi. Is there any planned support for GraphML i/o (http://graphml.graphdrawing.org/) in BGL? Has anyone played with this, and has experimental code? I think I saw it mentioned in the BGL documentation somewhere, but I can't find it. Thanks a lot. -- Tiago de Paula Peixoto <tiago(a)forked.de>

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bind on a iterator zip.
by chun ping wang 04 Apr '06

04 Apr '06

std::for_each(boost::make_zip_iterator(boost::make_tuple(beg1, beg2, beg3)), boost::make_zip_iterator(boost::make_tuple(end1, end2, end3)), ); now i want acess each indivdual tuple values using lambda and bind. How would i do that? My basic question is how would I use lambda to access the tuples value or each iteration value....

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