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[fusion] How to use transform Metafunction?
by Christian Henning 19 Mar '07

19 Mar '07

Hi there, since there is no example in the docs and no test for it. I was wondering how to use fusion's transform metafunction. Here is what I want to do. template <typename T> struct add_vector { typedef std::vector<T> type; }; struct A; struct B; struct C; int main() { typedef fusion::list< A, B, C > types; typedef fusion::transform< types, add_vector<> >::type vector_of_types; return 0; } The compiler is complaining that there are too few parameters for add_vector. In MPL you would just add _1 as the template parameter. But this doesn't work for fusion. So, how do I use it? Thanks, Christian

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[lexical_cast] lexical_cast<int>("1e4") == 1
by n.torrey.pines＠gmail.com 19 Mar '07

19 Mar '07

lexical_cast<int>("1e4") == 1 // because of the way streams work of course I think that in the interests of robustness, and unless a better solution can be found, lexical_cast<> should be secialized for some types. Another solution might be to make sure that the whole string argument got consumed (rejecting things like "123 " )

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which type of smart pointer to use?
by Vaclav 19 Mar '07

19 Mar '07

Hello, When I reset the main pointer to an object, I want all other pointers pointing to that object to be reset as well. Which type of smart pointer should I use? Example: boost::shared_ptr<MySillyClass> mySharedPtr1(new MySillyClass("test")); boost::shared_ptr<MySillyClass> mySharedPtr2 = mySharedPtr1; mySharedPtr1.reset(); if(mySharedPtr2.use_count() > 0) { TRACE("still used\n"); } else { TRACE("not used anymore\n"); } I am getting message "still used". I understand that is the normal behavior of boost::shared_ptr. Is there a smart pointer type that would print the second message? Reason: When I am done with an object, I would reset the main pointer to it and do not want other references to that object to be able to do anything with it. Thanks for advice! Vaclav

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MPL map error on g++
by Santosh Joseph 18 Mar '07

18 Mar '07

My code compiles on visual studio 8, but on g++ 3.3.2 (linux) and with g++ 3.4.4 (cygwin) it chokes with the following error: In function `void convertToScctsOpt()': optionmanager.cpp:119: error: expected init-declarator before "ScctsType" optionmanager.cpp:119: error: expected `, ' or `;' before "ScctsType" optionmanager.cpp:120: error: `ScctsType' undeclared (first use this function) Is some special command line argument needed? thanks for any help. #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_MAP_SIZE 50 #include <boost/mpl/map.hpp> #include <boost/mpl/at.hpp> #include <boost/mpl/pair.hpp> namespace bm = boost::mpl; typedef bm::map< bm::pair<Type1, MappedType1>, . . . bm::pair<Type41, MappedType41> > TypeToTypeMap; template<typename SoapType> inline void convertToScctsOpt() { typedef bm::at<TypeToTypeMap,SoapType>::type ScctsType; } ____________________________________________________________________________________ Now that's room service! Choose from over 150,000 hotels in 45,000 destinations on Yahoo! Travel to find your fit. http://farechase.yahoo.com/promo-generic-14795097

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Boost.Interprocess shared_memory.hpp
by Jean-Christophe Roux 17 Mar '07

17 Mar '07

Hello, I installed boost-1_35 this morning from cvs, which I believe contains the interprocess library. I took the interprocess doc from the vault. In the doc, there is at the end of the chapter "Shared Memory" a "Simple Example" that I am unable to compile because it contains the line: #include <boost/interprocess/shared_memory.hpp> but that file does not exist in my boost-1_35 folder. In /usr/local/include/boost-1_35/boost/interprocess, I have managed_shared_memory.hpp shared_memory_object.hpp but no shared_memory.hpp Maybe I am missing something obvious... Maybe the library from 1_35 and the docs from the vault are not compatible? Thanks for helping me out here. Jean-Christophe

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[boost-users][quickbook] Trying to get many sections onto one page
by Darren Garvey 17 Mar '07

17 Mar '07

Hello, I have a situation like this: [section Section 1] ... [endsect] [section Section 2] ... [endsect] and I'd like the generated html to have the layout of an article document-type but for it all to lie on one page. Obviously cut/paste is easy enough, but I'm wondering what the correct way to do this automatically is. Regards, Darren

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Fwd: SQL library with full embedded SQL-syntax
by Lyfar Dmitriy 17 Mar '07

17 Mar '07

Hello, sorry for my long responce. Rene Rivera wrote: > Sure... But we could use that same argument to propose that we write C++ > programs by writing an abstraction on top of C++ compilers in Python so > that we can remove the incompatibilities in the various C++ > implementations. Having had the displeasure of dealing with PL/SQL there > is one serious drawback to the language embedded approach, it ties ones > to the capabilities of the abstraction. May be you right, but I think that that comparison is incorrect, because of as far as I know SQL-standart doesn't include many useful features from various databases, opposite, the C++ standart, which is describes the whole language :) The main goal of the abstract layer for that library is, as Thorsten said, is to provide "portable" SQL for at least a simple queries. There is no goal to emulate features of each db for others at the first time. > Jorge Lodos wrote: > Sorry, I don't see how any of this applies -- just because the SQL is a string > doesn't mean it comes from an untrusted source. And, programmers that don't > validate input from untrusted sources deserve what they get.... I'd like to draw an intermediate conclusions: 1) The SQL library should provide a backdoor so you can still use string queries if you need to be non-portable or cutting egde etc. 2) Embedded SQL commands is type-safe, but strings are flexible and more useful in the 'real world' 3) It's hard to write one big abstract layer for all databases with single functionality and many people doesn't need in it usually. 4) ...? Phil Endecott wrote: > Well, an interface is not much use without some sort of implementation > behind it. Possible implementations for a "generic relational > interface" include an SQL database, on-disk data structures implemented > using something like stxxl, and in-memory data structures made > persistent using serialisation. A measure of a good generic relational > interface could be that it works well with all of these implementations. > > Thinking just about SQL backends, the basic question is whether we want to > > (a) hide the SQL, making the database accesses look more like C++ > function calls and data structures, or > > (b) make the SQL explicit, making the C++ code look more like SQL. > > I definitely vote for (a), and the possibility of moving an application > to something like stxxl is one of my motivations for that. If you interested in such libraries -- take a look at database template library(dtl) also. What do you think about containers overhead? Does the (a) variant means that the parsing of the result of query is something like parsing an Variant type? Is it always opportune? The people who wants to have type-safety of queries and platform independence will select the (b) variant, I hope :) ----- Best Regards, Dmitriy Lyfar

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Bug in boost.filesystem?
by Tom Bachmann 17 Mar '07

17 Mar '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, Is the following code expected to be portable? namespace fs = boost::filesystem; fs::rename (current_p, skin_p / current_p.leaf ()); Where current_p and skin_p are fs::path, where current_p is valid and skin_p is the result of dereferencing a directory iterator (that was not at behind-end position at time of dereferencing). For current_p = foo/10NfRaHD1AAICPMKZIC50FvmaHw==.medium.jpg skin_p = foo/bar (directory) the code causes an exception: boost::filesystem::path: invalid name "10NfRaHD1AAICPMKZIC50FvmaHw==.medium.jpg" in path: "10NfRaHD1AAICPMKZIC50FvmaHw==.medium.jpg" (that is, I believe, at the point where a temporary path object is constructed from current_p.leaf ()). This appears quiet strange to me, as I never mention the file in the code, and I'd expect the library to treat such oddities. The following code works: fs::rename (current_p, skin_p / fs::path (current_p.leaf (), fs::native)); Is this the expected behavior? - -- - -ness- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFF+/vPvD/ijq9JWhsRAhMdAKCDyLsi0EKzhUnVcM3GjKopqnpcCQCbBK4y vkNablkmw69y3xj6ulSNdvs= =izVN -----END PGP SIGNATURE-----

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Boost path to use for VC++ 8?
by Jeff Dunlap 17 Mar '07

17 Mar '07

Hello, I am new to VC++ (ver 8) and would really like to use Boost! This is what I have done: 1) I unzipped the boost download to c:\boost_1_33_1 2) At the command prompt, I executed: c:\boost_1_33_1\>bjam "-sTOOLS=VC-8_0" install bjam ran fine and a new directory was created: c:\boost\include\boost-1_33_1\boost c:\boost\lib I had assumed that using bjam's install parameter would modify whatever the path settings for the VC IDE are supposed to be, but that does not appear to happen. There are alot of paths and I want to make sure that I use the right one. What are the paths that I am supposed to include in VC++ when using the bjam param 'install' above? Secondly, I was thinking that maybe the 'stage' param might be a better bjam choice since the boost libraries are built in a common directory, thus making it easier to use. Are there drawbacks to using boost this way? Thank you very much

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RWmutex + sockets
by Bo Lorentsen 17 Mar '07

17 Mar '07

Hi ... I have been looking into your thread lib, and all seem fine and nice, but is it true that there where no RW mutex or is it just called something I did not know ? Also, ... are there some kind of URL / socket lib in boost ? /BL

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cache basics
by Gottlob Frege 17 Mar '07

17 Mar '07

I had an idea for a general cache, based on the idea that caches are essentially trying to avoid re-calling expensive functions with the same parameters as last time. So typically you build a cache key from the params, put it in a map, etc. But what if we did things slightly differently... template <typename T> struct cache { typedef boost::function< T () > retriever_function; typedef std::map<retriever_function, T> map; map m; T retrieve(retriever_function retriever) { map::iterator it = m.find(retriever); if (it != m.end()) { return it->second; } else { T t = retriever(); m[retriever] = t; return t; } } }; Basically, instead of building a key from the params, build a key from the params + the function that takes the params. Then, as a bonus, you don't need to worry about packing/unpacking the params - just let bind() do that for you! The other bonus is that you can cache things that may be created via different methonds. So what's the problem? The problem is that boost::function and boost::bind don't have operator<(), so you can't put a boost::function in a map. :-( (actually it appears boost::bind does have an operator<, but it doesn't do what I want - it actually bind's the operator< into a function!) Any advice? Any chance boost::function might gain a < operator? (One that compared the underlying function and the params, possibly handled different numbe of params, etc - although I could live with requiring all the param types to be the same. ie basically boost::function would pass most of the work off to the function object (ie bind)) Do I instead need to use tuples and pack/unpack the params myself (and write overloads for 0 to n params, handle return_type messes, etc etc etc )? - Tony

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[MPL] 2 Newbie Questions
by Scott Meyers 17 Mar '07

17 Mar '07

I'm trying to use the MPL for the first time, and I have two questions. First, I want to use BOOST_MPL_ASSERT to say that at least one of two conditions is true. For the time being, one of the conditions is always false, so this is what I've tried: BOOST_MPL_ASSERT(( false || boost::is_same<CallerConstraints, CodeConstraints::Ignore_Constraints> )); It won't compile, so I tried this: BOOST_MPL_ASSERT(( mpl::or_(false, boost::is_same<CallerConstraints, CodeConstraints::Ignore_Constraints>) )); It won't compile either. I'm guessing that I have to use mpl::false_ or something in place of false, but that doesn't work either. Can somebody please tell me the proper way to say what I want to say? My second question is about the existence of an MPL algorithm akin to the STL algorithm includes. Given two MPL vectors V1 and V2, I want to know if all the types in V1 are also in V2. I know about mpl::contains, but I can't find mpl::includes. Is there one, or do I need to write it myself? I have the MPL book, so references to that are fine, in addition to anything online. Thanks, Scott

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[filesystem] Puzzling behaviour on MSVC 7.1 with ofstream and wpath in binary mode
by Eoin 17 Mar '07

17 Mar '07

Hello, My development platform is Win XP with sp2. I am using a very recent (no older than a week) copy of the boost cvs version 1.34rc and the compilers are MSVC 7.1 and 8.0 both with the service packs. I've encountered some puzzling behaviour with filesystem::wpath's and filesystem::ofstream's when opened in binary mode and compiled with VC++ 7.1. When I attempt to open a binary ofstream with a wpath as its filename it will fail if the file did not already exist. This appears to be contrary to when the filename argument is a narrow filesystem::path. When the binary mode is not specified both files are created. Attached is a very small app. demonstrating the inconsistency. This only occurs with 7.1, when compiled with 8.0 both files will be created if they did not already exist. Kind regards, Eoin. #include <iostream> #include <boost/filesystem/path.hpp> #include <boost/filesystem/fstream.hpp> namespace fs = boost::filesystem; int main() { fs::wpath wide_filename = L"./Wide.txt"; fs::path narrow_filename = "./Narrow.txt"; fs::ofstream wide_fs(wide_filename, fs::fstream::binary); std::cout << ((wide_fs.is_open()) ? "Wide file open." : "Wide file not open.") << std::endl; fs::ofstream narrow_fs(narrow_filename, fs::fstream::binary); std::cout << ((narrow_fs.is_open()) ? "Narrow file open." : "Narrow file not open.") << std::endl; return 0; }

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Re: [Boost-users] Boost path to use for VC++ 8?
by Nathan McDaniel 16 Mar '07

16 Mar '07

Hi Jeff, I'm not real clear either on the difference between 'stage' and 'install' (seem to be different only in the default folders they place things), but this is what I'm doing: First, I build Boost with this command (I only want the release libraries and only statically linked--builds a bit faster): bjam "-sBUILD=release <runtime-link>static" "-sTOOLS=vc-8_0" --prefix=./boost-built install When it's done, you'll have a "boost-built" subfolder with a "boost" folder and a "lib" folder. I don't plan on routinely rebuilding 1.33.1, so I copy the "boost-built" folder into one of my project folders and delete the boost build directory/files. Then add the "boost-built\boost" subfolder to your include search path, and the "boost-built\lib" subfolder to your library search path. Nathan ---------- Forwarded message ---------- > From: Jeff Dunlap <jeff_j_dunlap(a)yahoo.com> > To: boost-users(a)lists.boost.org > Date: Thu, 15 Mar 2007 02:49:10 +0000 (UTC) > Subject: [Boost-users] Boost path to use for VC++ 8? > Hello, I am new to VC++ (ver 8) and would really like to use Boost! > > This is what I have done: > > 1) I unzipped the boost download to c:\boost_1_33_1 > > 2) At the command prompt, I executed: > c:\boost_1_33_1\>bjam "-sTOOLS=VC-8_0" install > > bjam ran fine and a new directory was created: > > c:\boost\include\boost-1_33_1\boost > c:\boost\lib > > > I had assumed that using bjam's install parameter would modify whatever > the > path settings for the VC IDE are supposed to be, but that does not appear > to > happen. There are alot of paths and I want to make sure that I use the > right > one. What are the paths that I am supposed to include in VC++ when using > the > bjam param 'install' above? > > Secondly, I was thinking that maybe the 'stage' param might be a better > bjam > choice since the boost libraries are built in a common directory, thus > making > it easier to use. Are there drawbacks to using boost this way? > > Thank you very much >

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iostreams filter help
by Aljaz 16 Mar '07

16 Mar '07

Hello I've been trying to get boost iostreams filter to work. Heres the code I managed to write, but theres something I cannot understand.. It works fine with one small text file and it will process the lines okay, but when I try to use another text file (which is much bigger) it wont recognize any line and will return 0 lines counted (though file has around 2 million lines).. What am I doing wrong? What could be the cause of this? Best regards Thanks for help Heres the code: #include <boost/iostreams/device/file.hpp> #include <boost/iostreams/filtering_stream.hpp> #include <boost/iostreams/filter/newline.hpp> #include <boost/iostreams/filter/line.hpp> #include <boost/ref.hpp> #include <fstream> #include <ostream> #include <iostream> #include <string> using namespace std; using namespace boost::iostreams; namespace io = boost::iostreams; class long_line_counter : public io::line_filter { public: explicit long_line_counter(int max_length = 80) : max_(max_length), count_(0) { } int count() const { return count_; } private: std::string do_filter(const std::string& line) { ++count_; return line; } int max_; int count_; }; int main() { filtering_istream fin; long_line_counter llc(80); fin.push(boost::ref(llc)); fin.push(file_source("test2.txt", ios::in | ios::binary)); char buf[4012]; while ( fin.read(buf, 4012) && (llc.count() < 7000) ) { std::cout << "read" << "\n"; } std::cout << llc.count() << "\n"; return 0; }

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[Serialization] issue with portable_binary_oarchive
by Dan Leibovich 16 Mar '07

16 Mar '07

Hi, I am trying to use the portable binary archive example. I need to serialize only integers and strings. I tried it on linux and solaris5.8. The result binary stream is not the same and deserialization fails. I used hex viewer and notice that the files are very similar except for some few differences which results from endienness issues. Can it be that the metadata is written differently on each platform. This is happens when I serialize derived class through a pointer to base class. (I used BOOS_CLASS_EXPORT) Below you will find a test case. It produce differ output on linux and solaris. Am I missing something? Thanks in advance Dan Leibovich #include <fstream> #include "portable_binary_oarchive.hpp" #include <boost/serialization/base_object.hpp> #include <boost/serialization/export.hpp> class Base { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & x; } protected: int x; public: Base() {} ; Base(int x_) : x(x_) {} ; virtual void foo() {} ; }; class Derived1 : public Base { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<Base>(*this); ar & y; } protected: int y; public: Derived1() {} ; Derived1(int x_, int y_) : Base(x_), y(y_) {} ; virtual void foo() {x++;} }; class Derived2 : public Base { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<Base>(*this); ar & z; } protected: bool z; public: Derived2() {} ; Derived2(int x_) : Base(x_), z(true) {} ; virtual void foo() {x--;} }; class Container { Base* b1 ; Base* b2 ; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & b1; ar & b2 ; } public: Container() {} ; Container(int x, int y) { b1 = new Derived1(x,y) ; b2 = new Derived2(x) ; } }; BOOST_CLASS_EXPORT(Derived1) ; BOOST_CLASS_EXPORT(Derived2) ; int main() { std::ofstream ofs("filename"); const Container c(1,2) ; portable_binary_oarchive oa(ofs); oa << c; }

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[Boost.Test] improving BOOST_CHECK_CLOSE for arguments == 0
by Pierre-Jules Tremblay 16 Mar '07

16 Mar '07

I've been having some problems using BOOST_CHECK_CLOSE() (1.33.1) in cases where one of the two arguments is exactly equal to zero: the tolerance check fails in this case (d'oh). I know that I can use BOOST_CHECK_SMALL() in those cases, but it's a real drag to have to write the boilerplate code to handle specific cases where one operand is zero. So this is what I've done: #define MY_CHECK_CLOSE(a,b,c) \ if (a == 0) { BOOST_CHECK_SMALL(b,c); } \ else if (b == 0) { BOOST_CHECK_SMALL(a,c); } \ else { BOOST_CHECK_CLOSE(a,b,c); } I wonder: did I miss something, is there a better way? If not, perhaps this logic could be integrated in the _CLOSE tools. pj

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[graph] Building a graph from file
by Marc Boyer 16 Mar '07

16 Mar '07

Dear all, I am a new boost::graph user, and I have a pb that should be very common, but I do not find any simple way to do it. I have a graph, with, in a file, some vertex name, and, in another file, edge described from vertex name, something like -- nodes.txt -- AAA BBB CCC -- edges.txt -- AAA BBB xx AAA CCC yy CCC AAA zz With the book, it is quite easy to set the vertex names in the graph (with an internal property and the name_map). What seems not easy to me is how to add the edges ? I add to find a way to get a vertex from its name, and the map only do the opposite. Did I have to build a tempory reverse map ? Best regards, Marc Boyer

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[fusion] cannot compile extension example
by Christian Henning 16 Mar '07

16 Mar '07

Hi there, same to my former email. The extension example does not compile with VC7.1. Here are the errors: \boost\libs\fusion\example\extension\test_example.cpp(25) : error C2039: 'is_associative' : is not a member of 'boost::fusion::traits' \boost\libs\fusion\example\extension\test_example.cpp(25) : error C2059: syntax error : ')' \boost\libs\fusion\example\extension\test_example.cpp(26) : error C2653: 'traits' : is not a class or namespace name \boost\libs\fusion\example\extension\test_example.cpp(26) : error C2059: syntax error : ')' \boost\libs\fusion\example\extension\test_example.cpp(26) : error C2143: syntax error : missing ';' before '}' \boost\libs\fusion\example\extension\test_example.cpp(26) : error C2059: syntax error : '}' \boost\libs\fusion\example\extension\test_example.cpp(27) : error C2653: 'traits' : is not a class or namespace name \boost\libs\fusion\example\extension\test_example.cpp(27) : error C2059: syntax error : ')' \boost\libs\fusion\example\extension\test_example.cpp(27) : error C2143: syntax error : missing ';' before '}' \boost\libs\fusion\example\extension\test_example.cpp(27) : error C2059: syntax error : '}' \boost\libs\fusion\example\extension\test_example.cpp(29) : error C2061: syntax error : identifier 'begin' \boost\libs\fusion\example\extension\test_example.cpp(29) : error C2143: syntax error : missing ')' before '==' \boost\libs\fusion\example\extension\test_example.cpp(29) : error C2059: syntax error : ')' \boost\libs\fusion\example\extension\test_example.cpp(29) : error C2457: '__FUNCSIG__': predefined macro cannot appear outside of a function body \boost\libs\fusion\example\extension\test_example.cpp(29) : error C2059: syntax error : ')' \boost\libs\fusion\example\extension\test_example.cpp(29) : error C2501: 'boost::detail::test_failed_impl' : missing storage-class or type specifiers \boost\libs\fusion\example\extension\test_example.cpp(29) : error C2365: 'boost::detail::test_failed_impl' : redefinition; previous definition was a 'function' c:\boost\boost\detail\lightweight_test.hpp(40) : see declaration of 'boost::detail::test_failed_impl' \boost\libs\fusion\example\extension\test_example.cpp(29) : error C2185: 'boost::detail::test_failed_impl' : illegal based allocation \boost\libs\fusion\example\extension\test_example.cpp(29) : fatal error C1903: unable to recover from previous error(s); stopping compilation Christian

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[fusion] Fill Em Up example doesn't compile
by Christian Henning 16 Mar '07

16 Mar '07

Hi there, I'm using VC7.1 and I try to compile the fill_em_up example I found in the cookbook example folder. Unfortunately the it doesn't compile. I have updated my boost to the latest CVS version. Here are the error messages: c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2039: 'category' : is not a member of 'boost::mpl::fusion_iterator<Iterator>' ...... c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2146: syntax error : missing ',' before identifier 'category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2065: 'category' : undeclared identifier c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2976: 'boost::fusion::detail::mpl_iterator_category' : too few template arguments c:\boost\boost\fusion\support\detail\mpl_iterator_category.hpp(28) : see declaration of 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2955: 'boost::fusion::detail::mpl_iterator_category' : use of class template requires template argument list c:\boost\boost\fusion\support\detail\mpl_iterator_category.hpp(28) : see declaration of 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2955: 'boost::fusion::detail::mpl_iterator_category' : use of class template requires template argument list c:\boost\boost\fusion\support\detail\mpl_iterator_category.hpp(28) : see declaration of 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2027: use of undefined type 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\support\detail\mpl_iterator_category.hpp(28) : see declaration of 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(33) : error C2146: syntax error : missing ';' before identifier 'category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(33) : error C2501: 'boost::fusion::mpl_iterator<Iterator>::category' : missing storage-class or type specifiers with [ Iterator=boost::fusion::extension::begin_impl<boost::fusion::mpl_sequence_tag>::apply<const boost::mpl::iterator_range<mpl_r_advance,mpl_r_end>>::iterator ] c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2039: 'category' : is not a member of 'boost::mpl::fusion_iterator<Iterator>' with [ Iterator=boost::fusion::extension::next_impl<boost::fusion::vector_iterator_tag>::apply<r_advance>::type ] c:\boost\boost\fusion\sequence\container\vector\detail\vector_n.hpp(68) : see reference to class template instantiation 'boost::fusion::mpl_iterator<Iterator>' being compiled with [ Iterator=boost::mpl::next<boost::fusion::mpl_iterator<boost::fusion::extension::begin_impl<boost::fusion::mpl_sequence_tag>::apply<const boost::mpl::iterator_range<mpl_r_advance,mpl_r_end>>::iterator>::iterator_type>::type ] c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2146: syntax error : missing ',' before identifier 'category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C3861: 'category': identifier not found, even with argument-dependent lookup c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2976: 'boost::fusion::detail::mpl_iterator_category' : too few template arguments c:\boost\boost\fusion\support\detail\mpl_iterator_category.hpp(28) : see declaration of 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2955: 'boost::fusion::detail::mpl_iterator_category' : use of class template requires template argument list c:\boost\boost\fusion\support\detail\mpl_iterator_category.hpp(28) : see declaration of 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2955: 'boost::fusion::detail::mpl_iterator_category' : use of class template requires template argument list c:\boost\boost\fusion\support\detail\mpl_iterator_category.hpp(28) : see declaration of 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(32) : error C2027: use of undefined type 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\support\detail\mpl_iterator_category.hpp(28) : see declaration of 'boost::fusion::detail::mpl_iterator_category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(33) : error C2146: syntax error : missing ';' before identifier 'category' c:\boost\boost\fusion\sequence\adapted\mpl\mpl_iterator.hpp(33) : error C2501: 'boost::fusion::mpl_iterator<Iterator>::category' : missing storage-class or type specifiers with [ Iterator=boost::mpl::next<boost::fusion::mpl_iterator<boost::fusion::extension::begin_impl<boost::fusion::mpl_sequence_tag>::apply<const boost::mpl::iterator_range<mpl_r_advance,mpl_r_end>>::iterator>::iterator_type>::type ] Is that a know problem? Thanks, Christian

2 1

How to sleep inside a boost::thread?
by Meryl Silverburgh 16 Mar '07

16 Mar '07

Hi, If I create a boost::thread like this: boost::thread thrd1(&reader); 1. how can I sleep inside the thread? (in the method 'reader') 2. when does the thread 'thrd1' terminate?

5 5

Re: [Boost-users] why the following regexp doesn't meet my requirement?
by llwaeva＠21cn.com 16 Mar '07

16 Mar '07

>> But, as I mentioned above, the whole matached string, namely #P{x}, >> will be replaced once the match is found. So, the character [^#] will >> also be replaced, that is not what I want. >Try a negative lookbehind: "(?<!#)#" will match any single "#" that is *not* preceded by another #. > The previous character (whatever it is) >does not form part of the result. >John. Thank you so much. It's amazing! I see that regex is really a powerful tool! BTW, in order to replace the pattern #P and avoid the string start with double #, I find it is all right to specify the exact times in matching when using replace_all_regex, for example replace_all_regex( source, boost::regex("([#]\{1\}P)|([#]\{1\}G)"), string("(?1 FIRST)(?2 SECOND)"), format_all ); of course, using the "negative lookbehind" approach also works in this problem replace_all_regex( source, boost::regex("((?<!#)#P)|((?<!#)#G)"), string("(?1 FIRST)(?2 SECOND)"), format_all ); For my case, the program might be used to handle a LARGE text (perhaps several megabytes). So, I am wondering which approach is faster! Thanks again!

1 0

why the following regexp doesn't meet my requirement?
by llwaeva＠21cn.com 16 Mar '07

16 Mar '07

Hi there, First of all, sorry for so many questions on using of regex. Actually, I am a beginner of regular expression; it is hard for me to understand some terms in document. I am going to extract a string in some pattern like #P{EXP_BEING_EXTRACTED} here, EXP_BEING_EXTRACTED is any expression which I want. For instance, xyz in #P{xyz} and 123_456 in #P{123_456}. But, I also need to ignore the case with double # as prefix, i.e. the output of ##P{123} should be kept unchanged. I use regex_search string source; // source contains the text being handled #P{x} or ##P{x} may occur boost::regex regexp; string::const_iterator start, end; boost::match_results<std::string::const_iterator> what; boost::match_flag_type flags = boost::match_default; regexp = "[#]\{1\}P[{]$[^}]*$[}]"; start = source.begin(); end = source.end(); if ( regex_search(start, end, what, regexp, flags) ) { // get the expression inside {} here // 1) get the text: string( what[1].first, what[1].second) // 2) replace the whole matched string, i.e., replace string(what[0].first, what[1].second); } The code above is fine for #P{x}; however, for the case ##P{x} regex_search still returns true. It seems that the regex_search firstly found the ##P{x} which is not match the regular expression; then, it go ahead from the second # and do the match again, so it found #P{x} finally. I don't know if the process is similiar to what I depict. Anyway, I just want to know how can I ignore the case ##P{x}. I try to modify the regular expression as follow regexp = "[^#]#P[{]$[^}]*$[}]"; But, as I mentioned above, the whole matached string, namely #P{x}, will be replaced once the match is found. So, the character [^#] will also be replaced, that is not what I want.

2 1

Re: [Boost-users] why the following regexp doesn't meet my requirement?
by llwaeva＠21cn.com 16 Mar '07

16 Mar '07

>Presumably it's because you're not anchoring the regexp to the start of the string - you're original regexp will work with 2 #s because > it finds a match starting at the 2nd one. If you were to start your regexp thus: "^[#]P" then it would not say that the ## case was correct. Thanks! But it seems still not solve the problem Because the pattern being searched doesn't necessary locate at the beginning of the source string, i.e. the source is likely "abcdefgd##P{xyz}ewerw" Thanks, anyway.

1 0

Re: [Boost-users] why the following regexp doesn't meet my requirement?
by Conway Allen 16 Mar '07

16 Mar '07

Presumably it's because you're not anchoring the regexp to the start of the string - you're original regexp will work with 2 #s because it finds a match starting at the 2nd one. If you were to start your regexp thus: "^[#]P" then it would not say that the ## case was correct. -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de llwaeva(a)21cn.com Envoyé : 16 March 2007 07:45 À : boost-users(a)lists.boost.org Objet : [Boost-users] why the following regexp doesn't meet my requirement? Hi there, First of all, sorry for so many questions on using of regex. Actually, I am a beginner of regular expression; it is hard for me to understand some terms in document. I am going to extract a string in some pattern like #P{EXP_BEING_EXTRACTED} here, EXP_BEING_EXTRACTED is any expression which I want. For instance, xyz in #P{xyz} and 123_456 in #P{123_456}. But, I also need to ignore the case with double # as prefix, i.e. the output of ##P{123} should be kept unchanged. I use regex_search string source; // source contains the text being handled #P{x} or ##P{x} may occur boost::regex regexp; string::const_iterator start, end; boost::match_results<std::string::const_iterator> what; boost::match_flag_type flags = boost::match_default; regexp = "[#]\{1\}P[{]$[^}]*$[}]"; start = source.begin(); end = source.end(); if ( regex_search(start, end, what, regexp, flags) ) { // get the expression inside {} here // 1) get the text: string( what[1].first, what[1].second) // 2) replace the whole matched string, i.e., replace string(what[0].first, what[1].second); } The code above is fine for #P{x}; however, for the case ##P{x} regex_search still returns true. It seems that the regex_search firstly found the ##P{x} which is not match the regular expression; then, it go ahead from the second # and do the match again, so it found #P{x} finally. I don't know if the process is similiar to what I depict. Anyway, I just want to know how can I ignore the case ##P{x}. I try to modify the regular expression as follow regexp = "[^#]#P[{]$[^}]*$[}]"; But, as I mentioned above, the whole matached string, namely #P{x}, will be replaced once the match is found. So, the character [^#] will also be replaced, that is not what I want. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

Re: [Boost-users] a question about Compiling Boost
by 林秀全 16 Mar '07

16 Mar '07

> hi, I am starting to learn Boost Library. > I use VC6.0 with Intel C++ compiler 9.1 to compile STLport5.1.2,and it is > successful. > So, I want to use intel C++ compiler 9.1 with VC6.0(sp6) and STLport5.1.2to compiler Boost_1_33_1, but it is failed. > I try my best to get the way, but I got nothing. > Can you help me? tell me how to do it !! > Thanks a lot! >

1 0

reversible_ptr_container.hpp compilation issue
by Brian Neal 16 Mar '07

16 Mar '07

Hi - We used the ptr_container library under gcc and Linux. We are now porting our software to the Integrity OS and the Green Hills Multi C++ compiler. This compiler has the EDG front end. It cannot compile reversible_ptr_container.hpp. I had to change this: class reversible_ptr_container { private: BOOST_STATIC_CONSTANT( bool, allow_null = Config::allow_null ); typedef BOOST_DEDUCED_TYPENAME Config::value_type Ty_; To this: class reversible_ptr_container { public: typedef BOOST_DEDUCED_TYPENAME Config::value_type Ty_; private: BOOST_STATIC_CONSTANT( bool, allow_null = Config::allow_null ); The compiler complains that the typedef Ty_ is private, but it is used in the public part of the class where it should not be accessible. I believe, but am not completely sure, that technically the compiler is correct. We have noticed that this EDG front end is very picky (in a good way). Thank you.

2 4

which version of boost to use with AMD64 / XP64 / Visual 2005
by Andreas Fabri 15 Mar '07

15 Mar '07

Hello, Can I build Rel 33_1 for AMD64 and XP64 and Visual 2005, or does only Rel candidate 34 support this platform? I need program options, so I have to compile libs. I am not sure about the right toolset for 64 bit libs. Can somebody help me? thanks in advance, andreas

1 0

filter iostreams
by Aljaz 15 Mar '07

15 Mar '07

Hello I'm having difficulties understanding some concepts of iostream filters. What I want to do? I want to have a filter (filter/line.hpp) that will split input (file) to lines. I've looked at class example but I still dont know how to use it for input (source) file. When I put filter on source stream, what is the best way to read it? I noticed most of examples use std::getline which gets line by default, but I decided to go for boost iostreams line filter because I thought it would be faster than getline approach.. Is this wrong? If not, how should I read file using line filter stream to get best preformance? Thanks for help

1 0

[fusion][mpl] How to make a vector of a vector of types
by Christian Henning 15 Mar '07

15 Mar '07

Hi there, subject probably sounds a bit strange but here is what I'm trying to accomplish. The problem description goes like this: using namespace boost; using namespace boost::fusion; struct A; struct B; struct C; int main() { typedef vector< A, B, C > types; // how to translates typed into the following?? typedef vector< std::vector<A>, std::vector, std::vector<C> > vector_of_types; return 0; } I'm looking for a generic approach to do this. To me it seems like it should be possible by taking parts of the MPL lib, like mpl::push_back, and parts of the fusion lib, like fusion::for_each. Any ideas? Thanks ahead, Christian

2 2

[statechart] - problem with sc::transition<> -> invalid use of 'boost::statechart::detail::no_context::no_function [with Event = jm::ffcp::ev_init]' to form a pointer-to-member-func
by Oliver.Kowalke＠qimonda.com 15 Mar '07

15 Mar '07

Hello, I get following error: /opt/boost/include/boost-1_33_1/boost/statechart/transition.hpp:33: error: invalid use of 'boost::statechart::detail::no_context::no_function [with Event = jm::ffcp::ev_init]' to form a pointer-to-member-function /opt/boost/include/boost-1_33_1/boost/statechart/transition.hpp:33: note: a qualified-id is required if I try to compile: #ifndef JM_FFCP_UNINITIALIZED_H #define JM_FFCP_UNINITIALIZED_H #include <boost/mpl/list.hpp> //#include <boost/statechart/custom_reaction.hpp> #include <boost/statechart/simple_state.hpp> #include <boost/statechart/transition.hpp> #include <jm/ffcp/events.h> #include <jm/ffcp/proto.h> namespace jm { namespace ffcp { namespace mpl = boost::mpl; namespace sc = boost::statechart; template< typename SocketDeviceT > struct initialized; template< typename SocketDeviceT > struct uninitialized : public sc::simple_state< uninitialized< SocketDeviceT >, proto< SocketDeviceT > > { typedef mpl::list< // sc::custom_reaction< ev_init > sc::transition< ev_init, initialized< SocketDeviceT > > > reactions; uninitialized() { uninitialized< SocketDeviceT >::custom_static_type_ptr("uninitialized"); } // sc::result react( ev_init const& ev) // { return this->template transit< initialized< SocketDeviceT > >(); } }; } } #endif // JM_FFCP_UNINITIALIZED_H Any hints? regards, Oliver

6 10

Problem with fs::path initialization in windows
by Timo 15 Mar '07

15 Mar '07

Hello, I have a little problem with initialization of boost filesystem path. I'm working on Cygwin in Windows XP. The fs::initial_path() and fs::current_path() both work ok and show something like: C:\cygwin\boost But when I try to use a path of my own, say: fs::path full_path( "C:\\cygwin\\boost" ); I get thrown with an exception. Same deal with the rest of the combinations I can think of: C:/cygwin/boost c:/cygwin/boost. c/cygwin and /cygwin don't throw but the paths are not found. So how do initialize the fs::path with a Windows type of directory path? Timo

4 6

serialization gives memory leaks due to throwing constructors
by gast128 15 Mar '07

15 Mar '07

Dear all, I ran into an exception thrown by the constructor. But there is no way to call 'delete_created_pointers' on the object since the object is never fully created (see below) Is there something to do about? void Foo() { std::vector<Bus> v(2); //from the examples std::stringstream sstr; //save try { _ASSERT(sstr.good()); boost::archive::xml_oarchive oa(sstr); oa << BOOST_SERIALIZATION_NVP(v); } catch (boost::archive::archive_exception& re) { DBG_TRACEN(re.what()); } //load v.clear(); //sstr.seekg(0); sstr.seekg(1); //generate dileberate error boost::archive::xml_iarchive* p = NULL; try { _ASSERT(sstr.good()); boost::archive::xml_iarchive ia(sstr); p = &ia; ia >> BOOST_SERIALIZATION_NVP(v); } catch (boost::archive::archive_exception& re) { DBG_TRACEN(re.what()); //won't work: p is always NULL if (p) { p->delete_created_pointers(); } } } This throwing c++ constructor stuff is btw the way to transport errors according to a lot of c++ gurus. But my persnonal opinion is that it sucks. Every created object must be guarded with exception safety. For large applications, this exception mecahnism is very tricky and sources for a lot unwanted application terminations or memory leaks. Wkr me

5 24

Compatible question with STLPORT
by yunxig 15 Mar '07

15 Mar '07

Dear sir, When I include STLPORT in VS 2005 as follows: VC++ Directories -> Include files ->STLPORT-5.1.2\stlport This "Options" is set in the first line. However there's compiling errors: boost\include\boost-1_33_1\boost\config\auto_link.hpp(175) : fatal error C1189: #error : "Build options aren't compatible with pre-built libraries". When I delete STLPORT-5.1.2 from "Options", there's no compiling error. But why? Thanks.

2 3

help replace_all_regex and format_literal
by llwaeva＠21cn.com 15 Mar '07

15 Mar '07

Hi there, I found that the behavior of replace_all_regex is weird while specifing format flag as format_literal. For example, I would like to replace %f and %g in a source with some text respectively. The code is string source = "#f = %f \r\n #g = %g \r\n"; string text1("<footi(a)tv.com>"); string text2("""name""<name(a)email.101.pi>"); replace_regex(source, boost::regex("%f"), text1, boost::regex_constants::format_literal); replace_regex(source, boost::regex("%g"), text2, boost::regex_constants::format_literal); The result is fine. However, I would like to use replace_all_regex instead. i.e. replace_all_regex( source, boost::regex("(%f|%g)"), string("(?1 loofon(a)56.com)(?2 ""name""<name(a)email.101.pi>"), boost::regex_constants::format_literal); However, because of format_literal, what I get is #f = (?1 loofon(a)56.com)(?2 "name"<name(a)email.101.pi>") #g = (?1 loofon(a)56.com)(?2 "name"<name(a)email.101.pi>") rather than #f = loofon(a)56.com #g = "name"<name(a)email.101.pi>" In my case, I need to handle a heap of patterns and using replace_all_regex is convenient. Any way to use both replace_all_regex and format_literal without going into the trouble mentioned above? Thanks in advance.

3 2

[Date_Time] and [Filesystem] - compile error when including headers in wrong order
by KLINIK Markus SDI2-G (AREVA NP GmbH) 15 Mar '07

15 Mar '07

Hello, including the header files "boost/date_time/local_time/local_time.hpp" and "boost/filesystem/operations.hpp" in this order results in the following compile error: 'boost::equivalent' : use of class template requires template argument list Swapping lines 1 and 2 of the following sample code works. I'm using MSVC 7.0, M$ Windows XP and boost-1.33.1 <code> #include <boost/date_time/local_time/local_time.hpp> // 1 // #include <boost/filesystem/operations.hpp> // 2 // int main(void) { return 0; } </code> Best Regards Markus

1 0

Boost.Numeric.Interval: Please specify rounding control mechanism.
by Andreas Fabri 15 Mar '07

15 Mar '07

Hello, even with the release candidate for 1_34 I get this error message c:/Boost/include/boost-1_34\boost/numeric/interval/hw_rounding.hpp(38) : fatal error C1189: #error : Boost.Numeric.Interval: Please specify rounding control mechanism. on AMD Turion with XP 64 and VC 2005. Can anybody fix this or give a hint what I have to find out on mt platform to fix it. thanks, andreas

3 5

[mutable_queue] Mutable Queue problem
by Anton A. Patrushev 15 Mar '07

15 Mar '07

Hi, I wonder if there is a way to put edge descriptors into Mutable Queue? So far it looks like it can handle only vertex descriptors. Am I right? Thanks, Anton.

2 1

Re: [Boost-users] SQL library with full embedded SQL-syntax
by Thorsten Ottosen 15 Mar '07

15 Mar '07

Maciej Sobczak wrote: > Hi, > > Jeff Garland wrote: > > >>Well, I'll be brutally honest -- I don't think I would go that >>direction. We didn't pick a database project last year because a >>majority of the mentors agreed that the 'dsl-based' approach was more of >>a toy than reality. The main reason for this is that in 'real-world' >>applications queries are often dynamic and must be built at run-time. > > > The other reason is that in 'real-world' you might want to call stored > procedures instead of manually glued pieces of ad-hoc SQL queries, in > which case the support in the area of query composition is probably not > very useful anyway. In the 'real-world' both things are used. Choosing C++ for a projects where databases are involved is probably rare and Java/C#/Python/Ruby is more likely. C++ doesn't exactly boost productivity, so it has to offer something else to be a condidate. And what can C++ offer? Type safety. -Thorsten

1 0

lambda usage
by Peng Yu 15 Mar '07

15 Mar '07

Hi, It seems that the lambda manual lacks of a simple working example. I'm made up the following example. But it's not working. Could you please show me how to make it work? Thanks, Peng #include <boost/lambda/lambda.hpp> #include <boost/lambda/core.hpp> #include <iostream> using namespace boost::lambda; int main() { std::cout << (_1 + _2)(10, 10) << std::endl; }

4 4

[lamba] Comparing return value of member function with ->*
by Boris 15 Mar '07

15 Mar '07

struct sample { int i; sample(int i) : i(i) { } bool odd() { return i % 2; } }; template <class T, class U> std::basic_ostream<T, U> &operator<<(std::basic_ostream<T, U>& ostr, sample s) { return ostr << s.i; } std::vector<sample> from; std::vector<sample> to; from.push_back(sample(1)); from.push_back(sample(2)); from.push_back(sample(3)); // Why doesn't this compile ... std::for_each(from.begin(), from.end(), if_then((_1 ->* &sample::odd) == false, std::cout << _1)); // ... but this does? Isn't it the same? std::for_each(from.begin(), from.end(), if_then(bind(&sample::odd, _1) == false, std::cout << _1)); Thanks in advance for any explanation which helps me to understand lamba expressions better, Boris

2 4

libraries accepted to boost
by andrzej 15 Mar '07

15 Mar '07

Hello, In the Boost home page I can see a number of libraries were accepted to Boost even more than a year ago. When are they going to be included in the official release? Thanks, &rzej ---------------------------------------------------------------------- Seksowne dziewczyny, szybkie samochody Zobacz >> http://link.interia.pl/f1a28

3 3

How to convert this into lambda expression
by Peng Yu 14 Mar '07

14 Mar '07

Hi, I have the following code which requires a definition of a class "not_fun". I want to replace it with lambda expression. Would you please let me know what the best way would be? Thanks, Peng #include <iostream> template <bool B> class not_fun; template <> struct not_fun<true> { static bool doit(bool x) { return x; } }; template <> struct not_fun<false> { static bool doit(bool x) { return !x; } }; template <bool B> class A { public: A() { } bool compute(bool b) const { if(not_fun::doit(b)) // how replace this with lambda expression? return true; return false; } private: }; int main() { A<true> a; std::cout << a.compute(true) << std::endl; }

1 0

C++ - STL & Shared memory
by Borse, Ganesh 14 Mar '07

14 Mar '07

Hi, I am developing an application with 2 unrelated, arbitary processes having a C++ shared hash map between them to store data. However, I am facing the problem of creating this template hash map in shared memory. Can boost be used for this purpose? Can anybody please suggest me the implementation which can be used to do this? Thanks in advance. Best Regards, Ganesh B. ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================

2 1

SQL library with full embedded SQL-syntax
by Dmitriy Lyfar 14 Mar '07

14 Mar '07

Hi I would like to participate in Google Summer of Code in this year. I reviewed boost projects for last years and found an interesting project, I think. If you go to the link below you will see a short description for that library: http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Google_Summe… The goal of this post is to define the main library features, which will be useful for users. Is that library useful for C++ community? If you are using(or have ever used) similar C++ libraries for work with SQL: which of features do you want to have? Also I want to notice one of the biggest beauty of that approach: you can get the compiler to type-check the SQL-expression, what do you think about that? Thank you. Best regards, Lyfar Dmitriy

1 0

how can I explicitly specify the lambda namespace
by Dmitriy Chumack 14 Mar '07

14 Mar '07

hi * In the documentation for lambda library from boost_1_33_1, in section "Getting Started"->"Conventions used in this document" said that in all examples implicitly used such declarations: using namespace std; using namespace boost::lambda; So the following will work: for_each(a.begin(), a.end(), std::cout << _1 << ' '); But how do I have to rewrite the above line of code to have it compiled without "using namespace boost::lambda;" before it? Thanks in advance.

4 3

Re: [Boost-users] Any function in boost::regex to escape everything of a text
by llwaeva＠21cn.com 14 Mar '07

14 Mar '07

> hi there, > I am working with a pattern-replace job with boost:regex. For > convenience, I use replace_all_regex to do that. Here is my code > > replace_all_regex( TEXT_TO_BE_REPLACED, regex_exp, format_string, > format_all ); > > TEXT_TO_BE_REPLACED is a text containing some patterns like %a, %b > and %c which will be repalced with a specific string(format_string) > that is inputed by user. However, the input string (format_string) > may have some characters related to the regular expression, such > characters must be escaped before the substitution. The following > > code is for that purpose > > > > replace_all( input, "$", "$$" ); > > replace_all( input, "\\", "\\\\" ); > > replace_all( input, ":", "\\:" ); > > replace_all( input, "?", "\\?" ); >> > replace_all( input, "(", "\$" ); > > replace_all( input, ")", "\$" ); > > > > The substitution works fine sometimes and fails when the input string > > (format_string) contains character which is not escaped. I just > > wonder if there is any function defined in boost::regex to escape all > > SPECIAL characters. > Use "format_literal" rather than "format_all" and all the characters in the > format string will be output "as is", and none will be treated as special > characters. > John. I try format_literal, but it reports error while compiling "error C2065: 'format_literal' : undeclared identifier" I am using the latest version of boost. Microsoft Visual Studio 2005, XP

2 1

[program_options] Unsure about linking options
by Ovanes Markarian 13 Mar '07

13 Mar '07

Hi! I am not sure if this is the issue of the program_options library or of all libraries at all. I got the HEAD revision from CVS and successfully compiled required libraries. One of the required libs is program_options. I have variations of the compiled lib with a name as: boost_program_options-vc-mt-1_35.lib When I try to recompile my code I get a linking error stating: LINK : fatal error LNK1104: cannot open file 'libboost_program_options-vc80-mt-gd-1_35.lib' My question is: Why is compiler still looking for libboost_program_options-vc80-mt-gd-1_35.lib? Do I have to change some config files? If yes, which? With Kind Regards, Ovanes Markarian

4 6

iostream and mapped_file
by Aljaz 13 Mar '07

13 Mar '07

Hello Is there any example how to use boost::iostream mapped_file ? I couldnt find any.. Which are the reasons that should make me consider using mapped_file stream? I want to read my text file as fast as possible (not all at once) - it should be seekable.. I know I should open file in binary mode and do read() to fixed size blocks to achieve the best preformance, but then I would have problems separating lines (I was consider using tokenizer but it would require stl data type so I would have to copy data). Is it possible to solve this problem with using boost::iostream filter so that it would be faster than getline()? Any help is highly appreciated! Thank you very much Aljaz

1 0

Any function in boost::regex to escape everything of a text
by llwaeva＠21cn.com 13 Mar '07

13 Mar '07

hi there, I am working with a pattern-replace job with boost:regex. For convenience, I use replace_all_regex to do that. Here is my code replace_all_regex( TEXT_TO_BE_REPLACED, regex_exp, format_string, format_all ); TEXT_TO_BE_REPLACED is a text containing some patterns like %a, %b and %c which will be repalced with a specific string(format_string) that is inputed by user. However, the input string (format_string) may have some characters related to the regular expression, such characters must be escaped before the substitution. The following code is for that purpose replace_all( input, "$", "$$" ); replace_all( input, "\\", "\\\\" ); replace_all( input, ":", "\\:" ); replace_all( input, "?", "\\?" ); replace_all( input, "(", "\$" ); replace_all( input, ")", "\$" ); The substitution works fine sometimes and fails when the input string (format_string) contains character which is not escaped. I just wonder if there is any function defined in boost::regex to escape all SPECIAL characters. Thanks in advance.

2 1

[lambda / multi_index] compilation problem
by Filip Konvička 13 Mar '07

13 Mar '07

Hi, getting lambda work with multi_index seems a bit tough for me.... the following compiles fine with MSVC++ 2003, but not when I #include sequenced_index.hpp or ordered_index.hpp. The error message says: error C2872: '_1' : ambiguous symbol could be 'c:\Boost\include\boost-1_33_1\boost\lambda\core.hpp(69) : const boost::lambda::placeholder1_type &boost::lambda::`anonymous-namespace'::_1' or 'c:\Boost\include\boost-1_33_1\boost\bind\placeholders.hpp(42) : boost::arg `anonymous-namespace'::_1' with [ I=1 ] This can of course be fixed by using boost::lambda::_1, but I doubt that it is the expected behavior. Can anyone please explain what I'm doing wrong? Thanks, Filip #include <boost/config.hpp> #include <boost/lambda/lambda.hpp> #include <boost/multi_index_container.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/hashed_index.hpp> //#include <boost/multi_index/sequenced_index.hpp> //#include <boost/multi_index/ordered_index.hpp> #include <list> using namespace boost; using namespace boost::lambda; int main(int argc, char* argv[]) { std::list<int> v(10); for_each(v.begin(), v.end(), _1 = 1); return 0; }

2 2

boost::ref and boost:::function
by misiu 13 Mar '07

13 Mar '07

Hello, Could you please tell me how to compare two boost::function objects packet with boost::ref. I have container which has boost::function elements and to add elements is not a problem but to remove particular one I don't know how to do that (compare two boost:ref-s). The problem is shown in the code below. Regards, Bartek //code #include <iostream> #include <list> #include <boost/ref.hpp> #include <boost/function.hpp> struct test{ int a; void operator() (int aa) { a += aa; } }; struct function_list { std::list<boost::function<void (int v)> > fun_list; void add(boost::function<void (int v)> fun) { fun_list.push_back(fun); } void remove(boost::function<void (int v)> fun) { std::list<boost::function<void (int v)> >::iterator iter; //HOW TO IMPLEMETN THIS FIND_IF? //std::find_if(fun_list.begin(), fun_list.end(), MISSING_PART); if(iter != fun_list.end()) fun_list.erase(iter); } }; int main(int argc, char **argv) { test a, b; function_list f; f.add(boost::ref(a)); f.add(boost::ref(b)); //DOES NOT WORK f.remove(boost::ref(a)); }

4 4

help extracting TAG with boost::regex
by llwaeva＠21cn.com 13 Mar '07

13 Mar '07

hi there, I am working with a TAG-oriented text with boost:regex. For example, the following pattern might occur in the text <before> <pre>Some Text</pre> <after> <pre> ddd </pre> In this case, I would like to extract everything between <pre> </pre>. Meanwhile, everything outside <pre> </pre> should be unchanged except that < is replaced by < and > is replaced by > For that purpose, I tried the following code boost::regex regexp("<\s*pre[^>]*>(.*?)<\s*/pre\s*>", boost::regex::icase); boost::match_results<std::string::const_iterator> what; if (regex_search(sometext, what, regexp,boost::match_default|boost::format_first_only)) { std::string between_tag = std::string(what[1].first, what[2].second) + "\r\n"; MessageBox(0, between_tag.c_str(), "", 0); std::string left_tag(sometext.begin(), what[1].first); std::string right_tag(what[1].second, sometext.end()); replace_all<string, LPCSTR, LPCSTR>( left_tag, "<", "<" ); replace_all<string, LPCSTR, LPCSTR>( right_tag, ">", ">"); sometext = left_tag + between_tag + right_tag + "\r\n"; } However, the code seems not works propely unless nothing outside <pre> </pre>. In addition, when the text being handled contains the \r\n, the code return error no matter if left_tag and right_rag is null or not. In a far more complicated case, a nested <pre></pre> might occur as follow <before> <pre><pre>Some Text</pre></pre> <after> <pre> ddd </pre> For this case, I only want to handle the outermost <pre></pre> and keep everything inside it unchanged, i.e., the inner <pre></pre> will be extracted as common text. Any idea? Thanks in advance.

2 1

Re: [Boost-users] [asio].[aix].[1_33_1] Update regarding test cases compilation
by Gaurav.Jain＠iflexsolutions.com 13 Mar '07

13 Mar '07

Hi chris, Christopher Kohlhoff <chris <at> kohlhoff.com> writes: > > Hi Gaurav, > > I just finished uploading it: > > http://sourceforge.net/project/showfiles.php?group_id=122478 > > Hopefully it will fix the issues for Solaris and AIX. > > On Wed, 21 Feb 2007 12:02:59 +0530, Gaurav.Jain <at> iflexsolutions.com said: > > No issues at all. Would you want me to try out boost.asio on Windows > > 2003 Server (SP1) - Itanium ? > > Yes please, if it's not too much trouble. The more the merrier :) > > Cheers, > Chris The bzip file of boost asio library available in the above mentioned link (boost_asio_0_3_8rc2.tar.bz2) is giving checksum error while extracting. Thanks & Regards, Gaurav Jain DISCLAIMER: This message contains privileged and confidential information and is intended only for an individual named. If you are not the intended recipient, you should not disseminate, distribute, store, print, copy or deliver this message. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete or contain viruses. The sender, therefore, does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required, please request a hard-copy version.

1 0

[BGL] Runaway memory usage
by Scott West 13 Mar '07

13 Mar '07

I have a particular graph that I'm constructing from a different form, namely a list of points, and a list of pairs of points (with distances) to represent the edges of the graph. I carry these around, then I try to make a graph with a vecS vertex set. The problem is, I think somehow I'm leaking memory. I've called g.clear() at the end of the use of the graph, but the memory usage appears not to drop when the function exits. Is there any reason why this could be the case? I know my description is pretty vague, just wondering if there was a standard operating procedure when working with semi-large graphs (~1000 nodes, ~43000 edges). It eats memory pretty fast, and I'm not comfortable enough with c++ to accurately diagnose where the leak is. Any help would be great, thanks! Scott West

1 0

[Boost.Random] Feature Request - Weibull Distribution
by johneddy101＠comcast.net 12 Mar '07

12 Mar '07

Is there any interest in adding a Weibull distribution to the list of random distributions? I have taken an initial cut at it and would be glad to share it if so. John

1 0

Newbie conversion of C# to boost::regex
by Jonathon Douglas 12 Mar '07

12 Mar '07

I am trying to convert the following C# code over to using boost::regex MatchCollection col = new Regex(@"\w+").Matches(@"slx://account/123456"); string table = col[1].Value; string id = col[2].Value; Table would equal "account" and id would equal "123456" in this. Ive tried using regex_match with this but it always finds no matches. Any sugestions ? Thanks, JD

3 5

Boost.Interprocess gcc 3.2.3 compilation problem
by laurent.vacca＠bnpparibas.com 12 Mar '07

12 Mar '07

Hi all, I've tried Interprocess library for a few days and everything seems to work perfectly However, when I try to compile example code with an older gcc (gcc 3.2.3), I'm getting errors regarding template instanciation /homer/lvacca/interprocess-2006--10/boost/interprocess/allocators/allocator.hpp:62: no class template named `pointer_to_other' in `boost::interprocess::detail' It seems gcc is unable to resolve the typedef in allocator.hpp (line 62) typedef typename detail::pointer_to_other <aux_pointer_t, const void>::type cvoid_ptr; to template class pointer_to_other in utilities.hpp Here are the different combos I tried: gcc 3.3 works fine with the two interprocess librairies available in boost vault (first release and october snapshot) and boost 1.33.1 gcc 3.2.3 + boost Interprocess + boost 1.33.1 fails Is gcc 3.2.3 supposed to work and compile Boost.Interprocess code ? Thanks a lot and congratulations for your great work! Laurent This message and any attachments (the "message") is intended solely for the addressees and is confidential. If you receive this message in error, please delete it and immediately notify the sender. Any use not in accord with its purpose, any dissemination or disclosure, either whole or partial, is prohibited except formal approval. The internet can not guarantee the integrity of this message. BNP PARIBAS (and its subsidiaries) shall (will) not therefore be liable for the message if modified. --------------------------------------------- Ce message et toutes les pieces jointes (ci-apres le "message") sont etablis a l'intention exclusive de ses destinataires et sont confidentiels. Si vous recevez ce message par erreur, merci de le detruire et d'en avertir immediatement l'expediteur. Toute utilisation de ce message non conforme a sa destination, toute diffusion ou toute publication, totale ou partielle, est interdite, sauf autorisation expresse. L'internet ne permettant pas d'assurer l'integrite de ce message, BNP PARIBAS (et ses filiales) decline(nt) toute responsabilite au titre de ce message, dans l'hypothese ou il aurait ete modifie.

2 1

[interprocess] Mutex on mac x86 fails
by Andrew Agno 12 Mar '07

12 Mar '07

I'm trying to run the following program, which works under Linux, on an intel mac: #include <boost/interprocess/sync/named_condition.hpp> #include <boost/interprocess/sync/named_mutex.hpp> #include <boost/interprocess/sync/scoped_lock.hpp> #include <iostream> using namespace std; namespace bi = boost::interprocess; int main( int argc, char **argv ) { cout << "Creating mutex" << endl; try { bi::named_mutex directoryMutex( bi::create_only, "MyVeryUniquelyNamedMutex" ); cout << "Creating scoped lock" << endl; bi::scoped_lock<bi::named_mutex> lock( directoryMutex ); cout << "All reqs met. Destroying mutex" << endl; bi::named_mutex::remove( "MyVeryUniquelyNamedMutex" ); } catch( std::exception &e ) { cout << "Problem encountered: " << e.what() << endl; } return 0; } I'm using a combination of the boost CVS for the interprocess header files and everything else from 1.33.1. The interprocess headers are current as of Mar 7. I've also tried open_or_create, and get the same result. On linux, this seems to work fine, with output: $ ./test Creating mutex Unlocking mutex Creating scoped lock All reqs met. Destroying mutex $ On the mac, it outputs: $ ./test Creating mutex Problem encountered: $ $ uname -a [...] 8.8.1 Darwin Kernel Version 8.8.1: Mon Sep 25 19:42:00 PDT 2006; root:xnu-792.13.8.obj~1/RELEASE_I386 i386 i386 $ g++ -dumpversion 4.0.1 $ g++ -dumpmachine i686-apple-darwin8

2 4

Re: [Boost-users] boost::ref and boost:::function
by Ovanes Markarian 12 Mar '07

12 Mar '07

On Mon, March 12, 2007 15:44, Peter Dimov wrote: > Misiu wrote: >> Ovanes Markarian napisaÅ(a): >>> [...] >>> >>> You could also skip the compare_functions implementation and use >>> boost::lambda and placeholder library to write you code like this: >>> std::find_if(fun_list.begin(), fun_list.end(), _1==fun); >> >> When I tried this solution (really nice one) on MSVC 2003 I got this >> error: >> >> d:\boost_ref_test\main.cpp(18): error C2666: 'boost::operator`=='' : 4 >> overloads have similar conversions > > You can't compare two function<> objects with ==. What you can do is compare > a function<> with the actual contents. That is, My appologies. I wrote this without double checking the doc. Thought it would work, since I remembered that there was a comparison operator. With Kind Regards, Ovanes Markarian

1 0

[lamba] boost::lambda::function_adaptor<Func>::apply means what?
by Boris 12 Mar '07

12 Mar '07

struct sample { int i; sample(int i) : i(i) { } bool odd() { return i % 2; } }; template <class T, class U> std::basic_ostream<T, U> &operator<<(std::basic_ostream<T, U>& ostr, sample s) { return ostr << s.i; } std::vector<sample> from; std::vector<sample> to; from.push_back(sample(1)); from.push_back(sample(2)); from.push_back(sample(3)); std::for_each(from.begin(), from.end(), if_then(bind(&sample::odd, _1) == false, bind(&std::vector<sample>::push_back, to, _1))); VC++ 8 displays dozens of error messages with the first one: error C2665: 'boost::lambda::function_adaptor<Func>::apply' : none of the 2 overloads could convert all the argument types Can anyone tell me how I need to change the lambda expression? Thanks, Boris

1 1

Andy Little's Physical Quantities System
by Polder, Matthew J 12 Mar '07

12 Mar '07

Hi, does anyone know where I can get a copy of Andy Little's Physical Quantities System? I know it wasn't accepted, but I think it would be useful for a project I'm working on. It's no longer in the Boost File Vault and I can't find it via Google. thanks, matthew

2 1

[date_time] iso time with local time differential
by Mojmir Svoboda 12 Mar '07

12 Mar '07

hello, i have simple task: convert iso time 20051108095122.5+0500 to seconds from 1900/01/01 00:00 UTC the thing is that doing something like: ... stringstream ss; local_time_input_facet * input_facet = new local_time_input_facet(); input_facet->format(local_time_facet::iso_time_format_specifier); ss.imbue(locale(ss.getloc(), input_facet)); ss << "20051108095122.5+0500"; local_date_time my_date(not_a_date_time); ss >> my_date; ... seems to drop the +-hhmm specifier and sets the zone to Z automatically in my_date. otherwise it seems to be parsed correctly. what am i doing wrong, please? mojmir This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.

1 0

[Serialization, XML] Suppress generation of class_id, tracking_level and version?
by Gerrit Brehmer 12 Mar '07

12 Mar '07

Hi, is it possible to suppress the in the xml-output generated attributes for object types (class_id, tracking_level and version)? Because it is better human writable/editable and in my case i have tested the reading of files w/o these attributes and it was all successful. Thanks in advance for your help!

3 2

[Threads] Conditions and avoiding lengthy mutex locks (background loading for a game)
by Peter Mackay 11 Mar '07

11 Mar '07

Hello, I'm trying to use the Boost Threads library to help me implement a background loading system for a game I'm writing. I want to enqueue load requests while the main game thread is running, and have a separate thread load the data and pass back the appropriate objects. Currently when I enqueue a new request, I notify a 'something to do' condition, which my loading thread waits on. The trouble is, when I notify it, the loader could be loading in the background, and has a lock on the mutex connected with the condition. Would anyone be able to offer me any advice on how to solve this? Many thanks, Peter P.S. Please find attached my current implementation. begin 666 loader.cpp M(VEN8VQU9&4@(FQO861E<BYH<' B#0H-"B-I;F-L=61E(#QB;V]S="]B:6YD M+FAP<#X-"@T*;&]A9&5R.CIL;V%D97(H*0T*.B!T:')E861?<VAO=6QD7V5X M:70H9F%L<V4I#0I[#0H)=&AR96%D+G)E<V5T*&YE=R!B;V]S=#HZ=&AR96%D M*&)O;W-T.CIB:6YD*"9L;V%D97(Z.G1H<F5A9%]P<F]C+"!T:&ES*2DI.PT* M?0T*#0IL;V%D97(Z.GYL;V%D97(H*0T*>PT*"2\O(%-I9VYA;"!T:&4@=&AR M96%D('1O(&5X:70N#0H)>PT*"0EB;V]S=#HZ;75T97(a)Z.G-C;W!E9%]L;V-K M(&QO8VLH;75T97(a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` ` end begin 666 loader.hpp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`` ` end

4 6

[graph] edmund_karp_max_flow vs kolmogorov_max_flow color map
by François Duranleau 11 Mar '07

11 Mar '07

Hi! It seems there is an inconsistency (to me) between color tagging of vertices in edmund_karp_max_flow and kolmogorov_max_flow algorithms. In the documentation of kolmogorov_max_flow, it says: "If the color of a vertex after running the algorithm is white the vertex belongs to the source tree else it belongs to the sink-tree (used for minimum cuts)." In short, vertices linked to the source are white. However, for edmund_karp_max_flow, it says: "At the end of the algorithm, the white vertices define the minimum cut set." Thus in this case, it's the vertices connected to the sink that are white. Why the difference in color tagging between the two algorithms? -- FranÃ§ois Duranleau LIGUM, UniversitÃ© de MontrÃ©al

2 5

equals() from boost/algorithm/string.hpp in top namespace?
by Olaf van der Spek 10 Mar '07

10 Mar '07

Hi, Why is equals() in the top namespace in 1.33.1? #include <boost/algorithm/string.hpp> #include <boost/array.hpp> int main() { boost::array<char, 4> a = { 1, 2, 3, 4 }; equals(a, a); return 0; }

3 3

[Serialization] How to restore ref-counted strings
by Bill Lear 10 Mar '07

10 Mar '07

We have a massive amount of data to serialize, on the order of several gigabytes. Lots of strings involved, maybe hundreds of millions. We discovered that the data structure in memory would bloat enormously when read back in from disk (say, from 2 gig to 3.1 gig). We think we have tracked this down to (gcc implementation) string reference counts not being "restored". I think a solution for us is to do something like the following: static map<string, bool> string_map; template <class Archive> void read_string(Archive ar, string& a_string) { string s; ar >> s; // read from disk map<string, bool>::iterator i = string_map.find(s); if (i == string_map.end()) { i = string_map.insert(make_pair(s, true)); } a_string = i->first; } void destroy_map() { string_map.clear(); } Then, when the data structures have all been read, invoke the destroy_map() method to clear the string_map object, thus decremented all refcounts of strings by one. Has anyone else encountered this and found a solution? Also, if anyone has bright ideas on a better data structure than std::map to use for storing hundreds of millions of strings at once for the above purpose, that also might be nice. Thanks. Bill

2 8

[MPL?] generating functions for all fields in a struct
by Christoph Duelli 10 Mar '07

10 Mar '07

Given a struct like struct X { int a; char b; float c; } and some function-'template' f is it possible to 'generate' - preferably by means of templates, MPL or something of the kind - variations of some function f for each of X's fields? E.g. I'd like to have functions like int getA() { return a; } char getB() { return b; } float getC() { return c; } ... (The functions I have in mind are more complex, obviously, but the idea is to generate one such function for all the fields of X.) I would like to avoid writing a macro call or something per field, as I would like the code to work (after recompiling it) even if the definition of X is changed and some fields are added. So, is there some generic 'iterator' over the fields of a struct? Thank you and best regards Christoph

4 4

Problem with iterator_property_map
by Jens Müller 10 Mar '07

10 Mar '07

I have a problem with the iterator property map adapter ... I have the following call in my program: bucket_sort(out_edges(*vi,g).first, out_edges(*vi,g).second, make_iterator_property_map(ord.begin(), get(edge_index, g)), std::back_inserter(sorted_edge_lists[get(get(vertex_index, g), *vi)].first) Bucket sort is a function written by me: /** Bucket sort algorithm. Accepts a range of object with a pair of ForwardIterators and outputs the elements in ascending order with an OutputIterator. \todo Maybe adding a sort order parameter is useful? \param begin Iterator pointing to the first element to be sorted. \param end Iterator pointing after the last element to be sorted. \param values ReadablePropertyMap with values of type int and keys having the type of *begin. \param out output iterator for the sorted elements. */ template<class ForwardIterator, class ValueMap, class OutputIterator> void bucket_sort(ForwardIterator begin, ForwardIterator end, ValueMap values, OutputIterator out) { int max = get(values, *begin); int min = get(values, *begin); for(ForwardIterator i = begin; i!=end; ++i) { if(get(values, *i)>max) max = get(values, *i); if(get(values, *i)<min) min = get(values, *i); } int n = (max - min)+1; std::cout << "max: " << max << ", min: " << min << std::endl; typedef typename std::iterator_traits<ForwardIterator>::value_type value_type; std::vector< std::list<value_type> > bucket(n); for(ForwardIterator i = begin; i!=end; ++i) { int index = get(values, *i); bucket[index-min].push_back(*i); } for(int i=0;i<n;++i) { typedef typename std::list<value_type>::iterator iter; for(iter b = bucket[i].begin(), e = bucket[i].end(); b!=e; ++b) { *out = *b; } } // for } // bucket_sort My graph is a LEDA graph, the edge_index property map is created by this code in leda_graph.hpp: class leda_graph_id_map : public put_get_helper<int, leda_graph_id_map> { public: typedef readable_property_map_tag category; typedef int value_type; typedef int reference; typedef leda::node key_type; leda_graph_id_map() { } template <class T> long operator[](T x) const { return x->id(); } }; template <class vtype, class etype> inline leda_graph_id_map get(vertex_index_t, const leda::GRAPH<vtype, etype>& g) { return leda_graph_id_map(); } template <class vtype, class etype> inline leda_graph_id_map get(edge_index_t, const leda::GRAPH<vtype, etype>& g) { return leda_graph_id_map(); } template <class Tag> struct leda_property_map { }; template <> struct leda_property_map<vertex_index_t> { template <class vtype, class etype> struct bind_ { typedef leda_graph_id_map type; typedef leda_graph_id_map const_type; }; }; template <> struct leda_property_map<edge_index_t> { template <class vtype, class etype> struct bind_ { typedef leda_graph_id_map type; typedef leda_graph_id_map const_type; }; }; (The edge_index part of this is new, I think). Well, when I try to compile it, I get: /home/jmueller/software-gcc34/boost/include/boost-1_33_1/boost/property_map.hpp: In function `Reference boost::get(const boost::put_get_helper<Reference, PropertyMap>&, const K&) [with PropertyMap = boost::iterator_property_map<__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >, boost::leda_graph_id_map, int, int&>, Reference = int&, K = leda::edge_struct*]': bucket_sort.hpp:27: instantiated from `void separator::bucket_sort(ForwardIterator, ForwardIterator, ValueMap, OutputIterator) [with ForwardIterator = boost::graph_traits<leda::GRAPH<int, int> >::out_edge_iterator, ValueMap = boost::iterator_property_map<__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >, boost::leda_graph_id_map, int, int&>, OutputIterator = std::back_insert_iterator<std::list<leda::edge_struct*, std::allocator<leda::edge_struct*> > >]' special_bfs.hpp:323: instantiated from `void separator::balanced_breadth_first_visit(const EdgeListGraph&, const typename boost::graph_traits<G>::vertex_descriptor&, BFSVisitor, ColorMap) [with EdgeListGraph = leda::GRAPH<int, int>, BFSVisitor = boost::bfs_visitor<boost::distance_recorder<boost::leda_node_property_map<int, int&, leda::node_map<int, leda::graph, -0x000000001>*>, boost::on_tree_edge> >, ColorMap = MapAsColorMap<boost::leda_node_property_map<int, int&, leda::node_map<int, leda::graph, -0x000000001>*>, boost::default_color_type>]' [...] /home/jmueller/software-gcc34/boost/include/boost-1_33_1/boost/property_map.hpp:312: error: no match for 'operator[]' in '(const boost::iterator_property_map<__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >, boost::leda_graph_id_map, int, int&>&)((const boost::iterator_property_map<__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >, boost::leda_graph_id_map, int, int&>*)(&pa))[k]' /home/jmueller/software-gcc34/boost/include/boost-1_33_1/boost/property_map.hpp:349: note: candidates are: R boost::iterator_property_map<RandomAccessIterator, IndexMap, T, R>::operator[](typename boost::property_traits<IndexMap>::key_type) const [with RandomAccessIterator = __gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >, IndexMap = boost::leda_graph_id_map, T = int, R = int&] Does anyone have any suggestions what I am doing wrong here?

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Use boost on AIX 5.2L?
by Aaron Tan 10 Mar '07

10 Mar '07

Hi, Does anyone know how to use boost libraries with VisualAge C++ 6 on AIX 5.2L? Regards, Aaron ____________________________________________________ Yahoo! Singapore Answers Real people. Real questions. Real answers. Share what you know at http://answers.yahoo.com.sg

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another problem with bind
by Christian Henning 09 Mar '07

09 Mar '07

Hi there, for whatever reason the compiler cannot decide the right call to "make". Please consider the following code: using namespace std; using namespace boost; template< typename T > void make( const T& t ) {} template< typename T > void make( const T& t, int i ) {} template< typename T > void make( const T& t, int i, int j ) {} struct a {}; struct b {}; void foo( string& s, a ) {} void foo( string& s, b ) {} int _tmain(int argc, _TCHAR* argv[]) { string str( "Hello" ); make( ( bind( static_cast<void(*)(string&, a )>( &foo ), _1, _2)( ref( str ) , a() )) ); return 0; } I want to make a call to the first make taking just on parameter, the bind object. But the compiler thinks something else: test.cpp(29) : error C2780: 'void make(const T &,int,int)' : expects 3 arguments - 1 provided test.cpp(16) : see declaration of 'make' test.cpp(29) : error C2780: 'void make(const T &,int)' : expects 2 arguments - 1 provided test.cpp(13) : see declaration of 'make' test.cpp(29) : error C2784: 'void make(const T &)' : could not deduce template argument for 'const T1 &' from 'boost::_bi::bind_t<R,F,L>::result_type' with [ R=void, F=void (__cdecl *)(std::string &,a), L=boost::_bi::list2<boost::_bi::list_av_2<boost::arg<1>,boost::arg<2>>::B1,boost::_bi::list_av_2<boost::arg<1>,boost::arg<2>>::B2> ] test.cpp(10) : see declaration of 'make' How can I make that clear to the compiler? Thanks ahead, Christian

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problem with bind and non-member function
by Christian Henning 09 Mar '07

09 Mar '07

Hi there, I'm using MSVC 7.1 and cannot get the following program to compile. I have tried the mailing list but couldn't find anything related. I'm sure it's a trivial problem but I cannot see right now. Anyone any idea? using namespace std; using namespace boost; struct a {}; struct b {}; void foo( string& s, a ) {} void foo( string& s, b ) {} int _tmain(int argc, _TCHAR* argv[]) { string str( "Hello" ); bind( static_cast<void(*)(string&, a )>( &foo ), ( ref( str ), a() )); return 0; } The error message is: c:\boost\boost\bind.hpp(63) : error C2825: 'F::result_type': cannot form a qualified name c:\boost\boost\bind\bind_template.hpp(15) : see reference to class template instantiation 'boost::_bi::result_traits<R,F>' being compiled with [ R=boost::_bi::unspecified, F=void (__cdecl *)(std::string &,a) ] test.cpp(18) : see reference to class template instantiation 'boost::_bi::bind_t<R,F,L>' being compiled with [ R=boost::_bi::unspecified, F=void (__cdecl *)(std::string &,a), L=boost::_bi::list1<boost::_bi::list_av_1<a>::B1> ] c:\boost\boost\bind.hpp(63) : error C2039: 'result_type' : is not a member of 'operator``global namespace''' c:\boost\boost\bind.hpp(63) : error C2146: syntax error : missing ';' before identifier 'type' c:\boost\boost\bind.hpp(63) : error C2955: 'boost::_bi::type' : use of class template requires template argument list c:\boost\boost\bind.hpp(112) : see declaration of 'boost::_bi::type' c:\boost\boost\bind.hpp(63) : fatal error C1903: unable to recover from previous error(s); stopping compilation

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iostream large file - performance
by Aljaz 09 Mar '07

09 Mar '07

Hello.. I've been testing fstream libary to read a huge text file (45 megabytes), which has around 2 million lines.. When I do (using fstream): Code: int line = 0; string str; ifstream is("file.txt"); while (!is.eof()) { getline(is, str); line++; }It takes about 9 seconds to read the whole file.. If I open file it with any 'good' text editor (editplus, notepad++ for instance) it takes a few seconds to read/load the whole file.. So I'm wondering.. What am I doing wrong? What should I do to achieve that speed - better preformance? Can boost::iostream do any better? Another thing: I tried writing data to deque (deque.pushback(str)) and was shocked on what happened.. It took ages to process the file, cpu constant at 99% so I closed the program after around 3 minutes.. Whats the 'proper' way to read files to memory? How do text editors do this? They load the same file in 4 seconds! I need a fastest way to read about 10 000 lines from text file at once.. Any help highly appreciated! Best regards A

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[BGL] Visitor events
by Anton A. Patrushev 09 Mar '07

09 Mar '07

Hi, I want to implement my own edge-based visitor. I need to implement new visitor events (for example on_initialize_edge or on_finish_edge). So, what should I do? Do I need to redefine entire visitor concept? Regards, Anton.

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Circular buffer library in boost
by Meryl Silverburgh 09 Mar '07

09 Mar '07

Hi, Is there a Circular buffer library in boost? If not, can you please tell me if there is a circular buffer library in c++? Thank you.

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[BGL] Dijkstra algorithm help!!!
by Alejandro Marcos Aragón 09 Mar '07

09 Mar '07

Hi, I would like to know if anyone knows about a simplified version of the Dijkstra algorithm code. The one in the library is too difficult for me to understand and modify since my knowledge about templates is limited. I need to modify it somehow to make it do something I want and I don't think I can use the visitor concept to do this. I posted a message before, where I explained that I was trying to use a visitor to solve my problem but I didn't get anywhere. This is what I'm trying to do: I want to store all the distances for a vertex i, not only the smallest distance. In the current algorithm, when an edge is relaxed (meaning that the distance from the source is less than the one before), the distance is overwritten in the DistanceMap. I would like to keep all the distances with their respective vertices. Therefore, I thought that a priority queue (min heap) would be the right data structure to use. However, I don't know how to access to this information using the visitor. Imagine a graph like this one: 3 B------C | / | / 2| /6 | / | / A Imagine that the A is the source and it finds first that the distance to C is 6 (A-C edge). Then, when it finds that a lower distance is obtained through A-B and B-C (5), I would like to keep the previous result as well in a priority queue. For vertex C the priority queue looks then like this: (5,B) / / / (6,A) I would appreciate any suggestions. Alejandro

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[state_saver] An extra constructor and a swapping destructor?
by Niels Dekker - mail address until 2007-11-30 08 Mar '07

08 Mar '07

The state_saver class at www.boost.org/boost/state_saver.hpp appears to be very useful for me. But I would like to propose two changes: First of all, I would like to have an extra constructor that would allow specifying a new value for the object (whose previous value will be restored when state_saver is destructed). Such a constructor would be very convenient, and it would also be conforming to io_state_saver's classes, by Daryle Walker. www.boost.org/libs/io/doc/ios_state.html A possible implementation would be: state_saver( T & object, const T & new_value ) : previous_value(object), previous_ref(object) { previous_ref = new_value; } Secondly I would suggest using a swap instead of an assignment, when restoring the previous value (when state_saver is destructed). A swap is much more likely to be fail-safe and efficient than an assignment. So I would propose the destructor to look as follows: ~state_saver() { // Doing "using std::swap", as suggested by Scott Meyers, // Effective C++ 3rd Edition, item 25, "Consider support // for a non-throwing swap" using std::swap; swap(previous_ref, previous_value); } Will these changes generally be considered an improvement? I already wrote Robert Ramey, the owner of state_saver.hpp. He also recommanded posting a message on this subject. So please let me know what you think! -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware C++ programmer at LKEB, Leiden University Medical Center

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BOOST_CHECK_PREDICATE vs BOOST_WARN_PREDICATE
by Alex Flint 08 Mar '07

08 Mar '07

The documentation page for the PREDICATE testing macros gives quite different syntax for the WARN vs CHECK methods: BOOST_WARN_PREDICATE( moo, (12)(i)(j) ); BOOST_CHECK_PREDICATE( std::not_equal_to<int>(), 2, (i,17) ); Since BOOST_WARN_PREDICATE and BOOST_CHECK_PREDICATE are only slight variants of one another, I'm confused as to why the syntax differs so much. Can anyone shed some light on this for me? Thanks, Alex

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program_option error
by Aljaz 08 Mar '07

08 Mar '07

What am I doing wrong? I get error 'boost::program_options::typed_value<T> *boost::program_options::value(T *)' : expects 1 arguments - 0 provided class options { public: unsigned int _option1; int _option2; void parse_options() { boost::program_options::options_description config; config.add_options() ("set1", boost::program_options::value<&_option1>()->default_value(200), "seting 1") ("set2", boost::program_options::value<&_option2>()->default_value(300), "seting 2"); } }; Thanks for help

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Re: [Boost-users] [boost::wave] Finding out if a macro is defined
by Ovanes Markarian 08 Mar '07

08 Mar '07

Hartmut, thanks for your help, but this issue is still alive ;) Just to be sure I did everything right, I took the entire head revision of boost and compiled it. I had no problems in the relevant libs. I also saw your changes in the cpp_context.hpp. The only problems I still get compiler errors using the flexi_string as described before. May usage scenario: token_type::string_type str("some string"); if(ctx.is_defined_macro(str)) { ... } There is still the iterator derefernece compiler error in the cpp_macromap.hpp: e:\boost\include\boost-1_35\boost\wave\util\cpp_macromap.hpp(396) : error C2228: left of '.get_value' must have class/struct/union type is 'const char' e:\boost\include\boost-1_35\boost\wave\cpp_context.hpp(198) : see reference to function template instantiation 'bool boost::wave::util::macromap<ContextT>::is_defined<const char*>(const IteratorT &,const IteratorT &)' being compiled with [ ContextT=boost::wave::context<token_groups::str_iter_type,token_groups::lex_iter_type>, IteratorT=const char * ] e:\projects\inpecting_wave\inpecting_wave\header_processor.cpp(178) : see reference to function template instantiation 'bool boost::wave::context<IteratorT,LexIteratorT>::is_defined_macro<boost::wave::cpplexer::lex_token<>::string_type>(const StringT &)' being compiled with [ IteratorT=token_groups::str_iter_type, LexIteratorT=token_groups::lex_iter_type, StringT=boost::wave::cpplexer::lex_token<>::string_type ] e:\boost\include\boost-1_35\boost\wave\util\cpp_macromap.hpp(396) : error C2228: left of '.c_str' must have class/struct/union the line: string_type name ((*it).get_value().c_str()); Still tries to call get_value on const char type. With Kind Regards, Ovanes

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Re: [Boost-users] [enable_if] using enable_if to specialize std::numeric_limits?
by james.jones＠firstinvestors.com 08 Mar '07

08 Mar '07

From: "Ovanes Markarian" <om_boost(a)keywallet.com> > As I wrote before, you can specialize numeric_limits class with your custom > type: > > > template<class T> > struct my_numeric_limits_impl > { > static T min() { return boost::decimal::decimal_limits<T>::min(); } > }; > > namespace std > { > template<> > class numeric_limits<your_custom_type1> : public > my_numeric_limits_impl<your_custom_type1> > {}; > > template<> > class numeric_limits<your_custom_type2> : public > my_numeric_limits_impl<your_custom_type2> > {}; > > } > > > What is wrong on this approach? The only problem I see here is the the > customer must include the specialization of numeric limits. But this can be > easily solved if you put in the same header where your_custom_type is > defined. So everyone using yyour_custom_type will automatically include > numeric_limits and if needed use the correct version. I have no problem putting this in a standard include file. The problem I have is that I'm trying to make it as easy as possible for users to add their own models of my decimal type concept. I'd like for the steps to be as simple as: (a) define a new model and then (b) specialize is_decimal_type. So far I've been able to use (b) to drive lots of other functionality, and I'm frustrated that I can't get this to help with std::numeric_limits. But it sounds like there may be no perfect solution here. Here's an example of how enable_if *has* helped me in this project. I'm defining a bunch of operators, e.g. operator+, which need to take arguments only of is_decimal_type objects. I can easily do this: template<typename LHSType, typename RHSType> typename enable_if_c< is_decimal_type<LHSType>::value || is_decimal_type<RHSType>::value, typename result_type_2<LHSType, RHSType>::type>::type operator+(const LHSType& lhs, const RHSType& rhs) { typedef typename result_type_2<LHSType, RHSType>::type result_type; return result_type(operation_t::ADD, lhs, rhs); } Works great, and doesn't interfere with other specializations/overloads of operator+. - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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[bind] [lambda] and [function] in combination with each other
by Christoph Borgolte 08 Mar '07

08 Mar '07

I'm using a map of comparing functions, created with Boost.Lambda and Boost.Function. These are of type boost::function<bool(double, double)> f = ( _1 <= _2 ) Now I need one of these functions bound to a specific value to send this function object as a callback function. Things are compiling fine, but the result is wrong. I've boiled it down to a minimal example: Any hints? TIA Chris --------8<--------------8<------------ #include <iostream> #include <map> #include <boost/lambda/lambda.hpp> #include <boost/lambda/bind.hpp> #include <boost/function.hpp> #include <boost/bind.hpp> typedef boost::function<bool(const double& ,const double& )> CMP_FNC_DBL_DBL; typedef boost::function<bool(const double& )> CMP_FNC_DBL; typedef std::map<std::string, CMP_FNC_DBL_DBL> FUNCTION_MAP; int main() { FUNCTION_MAP fm; fm["=="] = (boost::lambda::_1 == boost::lambda::_2); fm["!="] = (boost::lambda::_1 != boost::lambda::_2); //... CMP_FNC_DBL_DBL fdd = fm["=="]; std::cout << fdd(11., 10.) << std::endl; //works //Getting a function object via bind CMP_FNC_DBL_DBL fdd2 = boost::bind(&FUNCTION_MAP::operator[] , fm, std::string("==")); std::cout << fdd2(11., 10.) << std::endl; //works not //that is what I really need: a CMP_FNC_DBL_DBL bound to a constant value CMP_FNC_DBL f = boost::bind(boost::bind(&FUNCTION_MAP::operator[] , fm, std::string("==")), 4.); //doesnt compile std::cout << f(3) << std::endl; //works not } --------8<--------------8<------------ result: 0 1 1

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Compilation issue on MSVC 8 for mobile devices
by Silvatar Flood 08 Mar '07

08 Mar '07

When I try to compile boost 1.33.1 using MSVC 8.0 (VS.net 2005) for a mobile device, I get the following error: H:\PROJECTS\boost_1_33_1\boost/config/compiler/visualc.hpp(133) : fatal error C1189: #error : unknown CE compiler I tried to work around it by changing: # if defined(UNDER_CE) to # if 0 and it seems to work for the most part, except that it looks for certain intrinsic functions (_InterlockedIncrement for example) that apparently aren't available on Windows CE (though the platform API does have them, but not the compiler intrinsic versions). I could probably hack my way around this problem too, but I decided to wait and first ask if there's a more "proper" way to solve this issue. Any ideas? Yoni Lavi ____________________________________________________________________________________ Sucker-punch spam with award-winning protection. Try the free Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/features_spam.html

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Question about ifstream ranges
by Pfligersdorffer, Christian 08 Mar '07

08 Mar '07

Hello all! I face the problem of partitioning a file that i read with ifstream into portions that are to be processed by some clients. I want to ensure that a client only views a specific part (window, range) of the stream. So far I store 2 streamoffsets posStart and posEnd, call seekg on the stream, pass it to the client by ref and rely on the client to check when it reached posEnd. However, I certainly cannot copy the whole range into a new stream object and pass that one. Efficiency does matter. Any suggestions? Maybe some iterator-magic can be done? Thanks in advance, -- Christian Pfligersdorffer Dipl.-Ing. Bakk.rer.nat. Software Engineering EOS GmbH - Electro Optical Systems Robert-Stirling-Ring 1 D-82152 Krailling / Munich Phone +49 89 893 36-229 Fax +49 89 893 36-287 christian.pfligersdorffer(a)eos.info http://www.eos.info

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Re: [Boost-users] [enable_if] using enable_if to extend std::numeric_limits?
by james.jones＠firstinvestors.com 07 Mar '07

07 Mar '07

From: "Ovanes Markarian" <om_boost(a)keywallet.com> > Ok, I see. This is a bit more complex. ;) > Can you influence a type passed to numeric_limits? If yes you can do this: Thought about that, but it's suboptimal - see my response to me22 for more on this. Basically, I'd like any existing usage of numeric_limits<double> to be able to be replaced by numeric_limits<DecimalType> without any other changes. It wouldn't be *too* bad to do this: template< class T, class Enable = void > decimal_limits {}; template <> decimal_limits <double> : public std::numeric_limits <double> {}; template <> decimal_limits <float> : public std::numeric_limits <float> {}; template <class T> decimal_limits <T, enable_if<is_decimal_type<T> > > { // my decimal_limits implementation }; However, this would require users of my library to replace all references to numeric_limits with decimal_limits, so this is also less than ideal. Suppose the user has the following code: template<typename T = double> int f(const T& x) { x = abs(x); int i = 0; while(x > std::numeric_limits<T>::epsilon()) ++i; return i; } Ideally, the user should be able to do this: f<new_decimal_type> (some_new_decimal_value); and it should work with no modifications to the original function. - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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Re: [Boost-users] [enable_if] using enable_if to extend std::numeric_limits?
by james.jones＠firstinvestors.com 07 Mar '07

07 Mar '07

From: me22 <me22.ca(a)gmail.com> > I don't think you can "extend" classes that already exist. Note, for > example, that boost has integer_traits, and doesn't try to modify > numeric_limits. > > Why do you want the concept to be in numeric_limits? Can you not > simply use is_decimal_type? I should be more precise - by "extend" I really mean "specialize". I'd like to provide specializations for numeric_limits for my new decimal types. I can certainly just provide my own decimal_limits class (and have implemented this already), but the idea is to create a drop-in replacement for, say, double - and existing code likely uses numeric_limits<T> with T=double already, so being able to provide this with T=my_decimal_type would be ideal. - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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Re: [Boost-users] [enable_if] using enable_if to extend std::numeric_limits?
by james.jones＠firstinvestors.com 07 Mar '07

07 Mar '07

From: "Ovanes Markarian" <om_boost(a)keywallet.com> > Sorry, > > I ment enable_if< is_decimal_type<T> >::type. The ::type will be expanded to > either void or a derivable type. Maybe I'm misunderstanding, but how can I derive std::numeric_limits from enable_if, since std::numeric_limits is already defined? I can't do this: namespace std { template <typename T> class numeric_limits : private boost::enable_if<boost::decimal::is_decimal_type<T> >::type { public: static T min() { return boost::decimal::decimal_limits<T>::min(); } }; } and I can't do this: namespace std { template <typename T> class numeric_limits<T> : private boost::enable_if<boost::decimal::is_decimal_type<T> >::type { public: static T min() { return boost::decimal::decimal_limits<T>::min(); } }; } because this is not a specialization. - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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[boost-thread] memory leak (according to Boost.Test)
by n.torrey.pines＠gmail.com 07 Mar '07

07 Mar '07

This little program, compiled on VC++ 8.0 leaks memory, apparently. #define BOOST_AUTO_TEST_MAIN #include <boost/test/auto_unit_test.hpp> #include <boost/thread/thread.hpp> void f() {} BOOST_AUTO_TEST_CASE(threads_leak) { boost::thread thrd(&f); thrd.join(); } Output: Running 1 test case... *** No errors detected Detected memory leaks! Dumping objects -> {218} normal block at 0x00357458, 24 bytes long. Data: < 9 > 80 39 15 00 FF FF FF FF 00 00 00 00 00 00 00 00 {217} normal block at 0x00357398, 8 bytes long. Data: <Xt5 > 58 74 35 00 01 CD CD CD Object dump complete. Versions: Boost-1.33.1 VC++8.0 (debug mode) Windows XP extra lib: libboost_unit_test_framework-vc80-mt-gd.lib (not auto-linked) Can anyone using VC++ 8.0 and the release version of Boost confirm this? With Google, I found some past references to Boost.Thread leaking memory.

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iostreams use with asio tcp stream?
by Jeff 07 Mar '07

07 Mar '07

Everyone, Will I be able to use an asio tcp stream in an iostream filtering pipeline, so that I can first compress, then encrypt, then send the data over a tcp or udp connection? Thanks, Jeff

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[enable_if] using enable_if to extend std::numeric_limits?
by james.jones＠firstinvestors.com 07 Mar '07

07 Mar '07

Suppose I have a set of templates that have a common interface (each is a model of the same concept, to use that lingo). I'd like to extend std::numeric_limits to support this concept. I'm trying to find a way to use enable_if to do this, but I don't see how. Is this possible? Is there some other trick to doing this? Example with code (not real code): template< class U, class V > class model1; tempalte< class U, class V > class model2; template< class U > is_decimal_type { static const bool value = false; }; template< class U, class V > is_decimal_type < model1<U, V> > { static const bool value = true; }; template< class U, class V > is_decimal_type < model2<U, V> > { static const bool value = true; }; Would like to do this: template< class T > class numeric_limits< T > { // extensions go here }; But only if is_decimal_type<T>::value is true (so that the partial specialization only applies to my concept). Thanks, - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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[BGL] In what order does out_edge_iterator iterate?
by Shufei Fan 07 Mar '07

07 Mar '07

Hi, In my application, the order in which edges are retreaved is also important to me. So my question is, when I iterate through an vertex's out_edges, do they show up in the order in which the edges are inserted, or any other principals are used in order of iteration? Example: ...... typename graph_traits<Graph>::out_edge_iterator out_i, out_end; typename graph_traits<Graph>::edge_descriptor e; for (tie(out_i, out_end) = out_edges(v, g); out_i != out_end; ++out_i) { e = *out_i; Vertex src = source(e, g), targ = target(e, g); std::cout << "(" << get(vertex_id, src) << "," << get(vertex_id, targ) << ") "; } ...... How are these edges ordered in the output? And is it right all those iterators iterates in the same principals/order? Thanks, Shufei

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[boost::wave] Finding out if a macro is defined
by Ovanes Markarian 07 Mar '07

07 Mar '07

Hello All, using boost::wave (with context initialized as explained in the docs example) and trying to find out if some certain macro is defined leads to 2 errors: 1. Doc for context state: bool is_defined_macro(std::string const &name) const; But the source has no such function definition. I assume the signature was changed to: template <typename IteratorT2> bool is_defined_macro(IteratorT2 const &begin, IteratorT2 const &end) { return macros.is_defined(begin, end); } Trying to fix it and using the std::string::begin() and std::string::end() members to specify the begin and end range result in the error: c:\boost\include\boost-1_33_1\boost\wave\util\cpp_macromap.hpp(331) : error C2228: left of '.get_value' must have class/struct/union type is 'char' c:\boost\include\boost-1_33_1\boost\wave\cpp_context.hpp(150) : see reference to function template instantiation 'bool boost::wave::util::macromap<ContextT>::is_defined<IteratorT2>(const IteratorT &,const IteratorT &)' being compiled with [ ContextT=boost::wave::context<token_groups::str_iter_type,token_groups::lex_iter_type>, IteratorT2=char *, IteratorT=char * ] e:\projects\inpecting_wave\inpecting_wave\header_processor.cpp(177) : see reference to function template instantiation 'bool boost::wave::context<IteratorT,LexIteratorT>::is_defined_macro<char*>(const IteratorT2 &,const IteratorT2 &)' being compiled with [ IteratorT=token_groups::str_iter_type, LexIteratorT=token_groups::lex_iter_type, IteratorT2=char * ] This happens in cpp_macromap.hpp line 331: function source: template <typename ContextT> template <typename IteratorT> inline bool macromap<ContextT>::is_defined(IteratorT const &begin, IteratorT const &end) { // in normal mode the name under inspection should consist of an identifier // only token_id id = token_id(*begin); if (T_IDENTIFIER != id && !IS_CATEGORY(id, KeywordTokenType) && !IS_EXTCATEGORY(id, OperatorTokenType|AltExtTokenType)) { BOOST_WAVE_THROW(preprocess_exception, invalid_macroname, impl::get_full_name(begin, end).c_str(), main_pos); } IteratorT it = begin; error line >>>>>> string_type name ((*it).get_value()); <<<<<< error line typename defined_macros_type::iterator cit(current_macros -> find(name)); if (++it != end) { // there should be only one token as the inspected name BOOST_WAVE_THROW(preprocess_exception, invalid_macroname, impl::get_full_name(begin, end).c_str(), main_pos); } return cit != current_macros -> end(); } I assume compiler dereferences iterator to char and char has no member to get_value. Does anyone have suggestions? With Kind Regards, Ovanes Markarian

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[program_options] ignoring unknown options
by martux 07 Mar '07

07 Mar '07

Hi, I am having some trouble getting program_options to ignore unknown options. As suggested in the documentation I set allow_unregistered() but po::store(po::command_line_parser(argc, argv).options(pd.get()).allow_unregistered().run(), vm); po::notify(vm); still throws boost::program_options::unknown_option. Could anyone please make clear how to do it correctly? -- View this message in context: http://www.nabble.com/-program_options--ignoring-unknown-options-tf3361505.… Sent from the Boost - Users mailing list archive at Nabble.com.

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regex: seem to be missing something here
by Noah Roberts 06 Mar '07

06 Mar '07

fs::path upper("c:/differences", fs::native); fs::path checked(upper/"checked"); assert(fs::exists(upper)); assert(fs::exists(checked)); fs::directory_iterator end; rg::regex rgx("*ps", rg::regex::basic); for (fs::directory_iterator it(upper); it != end; ++it) { if (rg::regex_match(it->string(), rgx)) std::cout << "MATCH: "; else std::cout << "NOMATCH: "; std::cout << it->string() << std::endl; } Supposed to be looking for ps files. tried *\\.ps, which should work but also didn't. Doesn't match any of the strings. One example line of output: NOMATCH: c:/differences/Adj. speed test case 5 (metric units).ps Supposedly regex is greedy, no? It should accept . as a * element and continue to match everything up to ps and ps also...why no worky? Thanks.

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[Boost.Condition]
by Manuel Jung 06 Mar '07

06 Mar '07

Hi, I would like to know the waiting threads for a condition. Is there a way to calculate the number of "wait()"s which would be affected by a notifiy_all()? Maybe nobody needed this before? Or isn't this possible to implement such a thing with boost::condition and i have to count the waiting threads on the application level? Greetings Manuel Jung

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[Serialization] how to use serialization in windows dll
by jiang.yu(mos) 06 Mar '07

06 Mar '07

Hi! I meet trouble in use serialization in dll in dll export a function like hi_dll() void hi_dll() { std::map<std::string,int> m_map; std::ostringstream os; boost::archive::text_oarchive oa(os); oa & m_map; std::cout << os.str() << std::endl; } and in exe there is a function hi_exe() code is the same as hi_dll void hi_exe() { std::map<std::string,int> m_map; std::ostringstream os; boost::archive::text_oarchive oa(os); oa & m_map; std::cout << os.str() << std::endl; } in Debug mode , the exe call both hi_exe() and hi_dll() will assert at extended_type_info.cpp line 71 assert(lookup(eti) == m_self->m_map.end()); vc7.1 boost 1.33.1 link with serialization as dll then what to do? thanks in advance. Best Regards mos

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Problem with graphs - constructor throwing vector::_M_fill_insert
by Tamas Marki 06 Mar '07

06 Mar '07

Hi, I'm having a problem with the graph library. The problematic function looks like this below. Edge is a simple struct with vertex_a, vertex_b and cost as its members. The trick is that I need to process this big graph a few times, each time throwing out some edges and keeping others, hence the reindexing and mapping of these. I've used the graph lib previously, and worked, I'm just unable to find what am I doing wrong this time. Any help would be welcome. Thanks in advance. typedef std::pair<int, int> edge; typedef boost::adjacency_list < boost::listS, boost::vecS, boost::directedS, boost::no_property, boost::property < boost::edge_weight_t, int > > graph_t; typedef boost::graph_traits < graph_t >::vertex_descriptor vertex_descriptor; typedef boost::graph_traits < graph_t >::edge_descriptor edge_descriptor; graph_t* KGMReader::buildGraph (vector<edge>& edgs, vector<int>& weights, vector<int>& vertexmapping, int rootter) { edgs.clear (); weights.clear (); vertexmapping.clear (); for (vector<Edge>::iterator it = edges.begin (); it != edges.end (); ++it) { if (keepEdge (*it, rootter)) { vector<int>::iterator v1 = find (vertexmapping.begin (), vertexmapping.end (), it->vertex_a); vector<int>::iterator v2 = find (vertexmapping.begin (), vertexmapping.end (), it->vertex_b); if (v1 == vertexmapping.end ()) { vertexmapping.push_back (it->vertex_a); v1 = find (vertexmapping.begin (), vertexmapping.end (), it->vertex_a); } if (v2 == vertexmapping.end ()) { vertexmapping.push_back (it->vertex_b); v2 = find (vertexmapping.begin (), vertexmapping.end (), it->vertex_b); } edgs.push_back (edge (v1 - vertexmapping.begin (), v2 - vertexmapping.begin ())); weights.push_back (it->cost); edgs.push_back (edge (v2 - vertexmapping.begin (), v1 - vertexmapping.begin ())); weights.push_back (it->cost); } } qDebug () << "Vertexes: " << vertexmapping.size () << " edges " << edgs.size () << ", weights " << weights.size (); graph_t *g = 0; try { g = new graph_t (edgs.begin (), edgs.end (), weights.begin (), vertexmapping.size ()); } catch (exception& e) { qDebug () << "caught!!! " << e.what (); g = 0; } return g; } -- Tamas Marki

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program_options - save configuration
by Aljaz 06 Mar '07

06 Mar '07

I wonder if there are any functions in boost program options libary to save them back to configuration file? Maybe any example? Thanks for help

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boost::lambda::bind with shared_ptr
by Steven S. Klug 05 Mar '07

05 Mar '07

Is there any way using BLL's bind to bind to shared_ptrs in a container? e.g.: class MyClass { public: std::string MyFunc() { return str; } private: string str; }; vector<shared_ptr<MyClass> > v; find_if( v.begin(), v.end(), boost::lambda::bind( &MyClass::MyFunc, _1 ) == string( "steve" ) ); In visual studio with the scenario I get errors indicating it can't find MyFunc in the interface for shared_ptr, which you'd expect, except for the fact that boost::bind works with shared poiners. Is it the case that boost::lambda::bind doesn't? If so, that's unfortunate as it rules out using lambda with containers of shared_ptrs in a lot of cases. What am I missing? sklug

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