September 2008 - Boost-users

Missing MSVCR80.DLL
by Slava D 13 Sep '08

13 Sep '08

guys, please, could you help me. I have installed boost_1_35 with the BoostInstaller (taking the precompiled binaries). When I check any dll-s with the dependency walker (say, release version BOOST_DATE_TIME-VC-MT-1_35.dll or debug version BOOST_DATE_TIME-VC-MT-GD-1_35.dll), it says that it is missing MSVCR80.dll for the release version and MSVCR80D.DLL for the debug version. At the beginning I thought there was something wrong with my PC. I tried on another machine and got the same results. On one machine I have XP with SP2 and on another I have XP with SP3. Some people are saying that this usually shows some mess with the manifest files. But I did not need to generate the manifest file as I took the binaries from the Installer directly. Please, could you help me. Any advice would be greatly appreciated. many thanks, Slava

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Serialization: storing different representations in different archive types
by Simon Fraser 13 Sep '08

13 Sep '08

I have a program that saves program state in both binary and XML archives. I'd like to store one of the model objects in my program in different formats, depending on whether the output archive is XML or binary: for XML archives, I'd like to use a human readable-format, and for binary archives I'd like to use a much more compact representation. I don't see any methods on Archive that let me ask if the output is a textual format (text or XML). I could dynamic_cast in my load/save methods, but that doesn't extend to new kinds of archives that may be implemented in future. Is there a way to do what I want to do? Thanks Simon

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enabled_shared_from_this: bad_weak_ptr exception + online doc explanation
by cxv＠sfu.ca 13 Sep '08

13 Sep '08

Hi all, I have a class called TextTool. In its constructor I initialize a member variable. This member variable needs a pointer to TextTool in *its*constructor. Hence I need to have a pointer to "this" (TextTool) and then pass it to the constructor of the member variable. This is a summery of my code: *TextTool.h* class TextTool : public Tool, public boost::enable_shared_from_this<TextTool> { public: TextTool(QDialog *taskDialogue); private: boost::shared_ptr<ToggleControl> bold; //Member variable that needs a pointer to TextTool in its constructor }; *TextTool.cpp* TextTool::TextTool(QDialog *taskDialogue) : Tool(this->name) { boost::shared_ptr<TextTool> pointerToThis = TextTool::shared_from_this(); //ERROR OCCURS ON THIS LINE bold = boost::shared_ptr<ToggleControl>(new ToggleControl(pointerToThis)); } I get a runtime exception: "boost::bad_weak_ptr at memory location 0x0012fccc" when executing the above mentioned line. On the BOOST online documentation, I dont understand what this line means: "**this* must be a subobject of an instance *t* of type *T* . There must exist at least one *shared_ptr* instance *p* that *owns* *t*.". Do I need to have an instance (t) of TextTool (T) as a member variable of the class TextTool? Won't this lead to loops in my situation (since I want the "this" pointer to be created in the constructor itself)? Any help? Thanks, /C.

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jam environment variables
by Mika Heiskanen 13 Sep '08

13 Sep '08

Hello, Jam documentation mentions that "Jam picks up variable settings from your environment by default". However, I could not find any documentation on what environment variables affect what options. In particular, I am looking for a way to pass on to Jam the --layout and --build-type options via environment variables. Currently I am building a boost rpm for local distribution by using the following command sequence in the rpm .spec file: %build ./configure --prefix=%{_prefix} --libdir=%{_libdir} cat Makefile | sed -e 's/BJAM_CONFIG=/BJAM_CONFIG=--layout=system --build-type=complete/' > Makefile.new mv Makefile.new Makefile make all If I understand correctly, I should be able to define the compile options via environment variables instead of resorting to a hack like above. I'd appreciate any pointers to more detailed documentation on how to accomplish the above with environment variables alone. Thank you in advance, --> Mika Heiskanen / FMI

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what is a vertex_descriptor? (boost graph library)
by Will Chen 13 Sep '08

13 Sep '08

So it looks like it's basically a 0-based integer. When I start adding vertices to an empty graph, the first one comes back as 0, the second as 1, third as 2...etc. Is it always an integer? When is it not an integer? I really want a way to easily convert vertex_descriptor's and edge_descriptor's to and from strings. Any ideas? -- William Yun Chen '09 Hinman Box 1826 Dartmouth College Hanover, NH, 03755

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retrieve the path of an opened mapped_file!
by Michael Bradley Jr 13 Sep '08

13 Sep '08

Hi, looking for an interface to access the path of an opened boost::iostreams::mapped_file file or its mapped_file_params parameter ? Any hint ? thx in advance Mike

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Boost.tokenizer and char_separator
by Sean Farrow 13 Sep '08

13 Sep '08

Hi: I am in the process of using boost::tokenizer in a bimap. I have the following definition: boost::bimaps::bimap<boost::bimaps::set_of<boost::tokenizer<boost::char_ separator<char>>>, std::string> TokensList; I need to use the " " as the separator. How can I do this? Any help apreciated. Sean. __________ Information from ESET NOD32 Antivirus, version of virus signature database 3439 (20080912) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

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boost serialization and datatype mismatch
by sam p 12 Sep '08

12 Sep '08

Hi, How to validate datatype before it gets deserialized? e.g. struct Abc { std::map<string,string> tmpMap; int a; float d; std::list<string> stringList; void serialize(boost::archive::polymorphic_oarchive & ar, const unsigned int file_version) { ar & tmpMap; ar & a; ar & d; ar & stringList; } void serialize(boost::archive::polymorphic_iarchive & ar, const unsigned int file_version) { ///////////////////////////////////////////////////////////////////// /* Now the right thing to do over here is ar & tmpMap; ar & a; ar & d; ar & stringList; */ /////////////////////////////////////////////////////////////////////// //But instead, if by mistake user writes something like ar & a; ar & d; ar & stringList; ar & tmpMap; /* So how to handle such problem? Can I validate data somehow before it gets deserialized? On some platforms like SuSE linux I have observed that such thing doesn't throw exception and we get SEGV. */ } }; Thanks, Sameer

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[serialization] missing </serialization> tag
by Mojmir Svoboda 12 Sep '08

12 Sep '08

afternoon, i am serializing graph::adjacency_list via boost::serialization but there is no tag </serialization> at the end of the generated file. what am i doing wrong, please? i suspect also there may be bug in binary serialization in 1.36.0 because i cannot read generated file. i'll try to isolate this in nearest future. best regards, mojmir

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Puzzled: compiler can't find a match for function call
by Zeljko Vrba 12 Sep '08

12 Sep '08

In the code below, the compiler complains with q.cc:39: error: no matching function for call to `inc2(boost::fusion::map<boost: :fusion::pair<detail::KEY, int>, boost::fusion::void_, boost::fusion::void_, boo st::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::vo id_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_>&)' id_t<K> is the SAME type as the expanded BF::map type in inc1; it even works as the return type of inc1, yet I can't use it as an argument to inc2. What am I missing? This happens both on gcc 3.4 and SunCC 12. #include <boost/fusion/include/at_key.hpp> #include <boost/fusion/include/comparison.hpp> #include <boost/fusion/include/erase_key.hpp> #include <boost/fusion/include/io.hpp> #include <boost/fusion/include/joint_view.hpp> #include <boost/fusion/include/map.hpp> #include <boost/fusion/sequence/intrinsic/at_key.hpp> #include <boost/fusion/sequence/intrinsic/value_at_key.hpp> namespace detail { namespace BF = boost::fusion; struct KEY; template<typename K> struct id_t { typedef BF::map<BF::pair<K, int> > type; }; template<typename K> inline typename id_t<K>::type& inc1(BF::map<BF::pair<K, int> > &id) { ++BF::at_key<K>(id); return id; } template<typename K> inline typename id_t<K>::type& inc2(typename id_t<K>::type &id) { ++BF::at_key<K>(id); return id; } void f() { BF::map<BF::pair<KEY, int> > m(12); inc1(m); inc2(m); } }

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