- Boost-users - lists.boost.org

heterogeneous tree container
by Hicham Mouline 08 Jul '10

08 Jul '10

Hello, I have need for a heterogeneous tree container that holds different types (all of them primitive, int, double...) except for the leaf nodes which would hold a POD. The depth of the tree is N, known at runtime, and constant through all the paths, the actual types of each node are only known at runtime as well. Each level holds the same type. The number of children at 1 level, is variable from 1 parent to the next. root (no data here) | | | type1 type1 type1 | | type2 type2 ... typeN typeN .... typeN There are no paths from root to leaf with a depth different from N. typeN is a struct containing only primitive types, known a compile-time, and instances of it are the result of calling a complex function with arguments of type1.... type_N-1. Note that I will generate the [1, N-1] part of the tree sequentially, but then call the complex function in parallel. I have looked at the ntree.hh but it seems to be a homogenous container. Any reusable container out there for this purpose, or is ntree reusable somehow? Regards,

2 1

[conversion] Is there a boost lib for converting octet array to integral types?
by Mostafa 08 Jul '10

08 Jul '10

Hi all, Is there a boost utility for converting an array of octets to an integral type? Something along the lines of: boost::uint8_t const octetBuf[] = {0x23, 0x4e}; boost::uint32_t const thirtyTwoBit = some_function(octetBuf); Where some_function takes care of the padding based on endianness. Thanks, -Mostafa

1 0

Serialization XML on windows and linux
by QUILLET Jean-Charles 08 Jul '10

08 Jul '10

Hi, I've been using the boost serialization for quite a few projects and it works realy well in many different situations. But today I'm facing a problem, I find very difficult to solve. I serialize objects in a XML archive for a project working on linux and windows using boost 1.38. And oddly my files are not compatible between the two plateforms. When I try to deserialize an object saved on a different plateform, the application crashes despite the fact that I catch possible exceptions. When I compare the two files, it seems that I have a difference of class_id Here is a sample of what I have on linux: <m_scene3D class_id="4" tracking_level="0" version="0"> <pNode class_id="6" class_name="Group" tracking_level="1" version="0" object_id="_1"> <Node class_id="5" tracking_level="1" version="0" object_id="_2"></Node> <noeuds class_id="7" tracking_level="0" version="0"> <count>0</count> <item_version>0</item_version> </noeuds> </pNode> ... </m_scene3D> And the same object on windows: <m_scene3D class_id="4" tracking_level="0" version="0"> <pNode class_id="6" class_name="Group" tracking_level="1" version="0" object_id="_1"> <Node class_id="7" tracking_level="1" version="0" object_id="_2"></Node> <noeuds class_id="8" tracking_level="0" version="0"> <count>0</count> <item_version>0</item_version> </noeuds> </pNode> ... </m_scene3D> In my file on windows, I don't have any object of a class_id="5", weird... Does any one know any reason for this behaviour ? Any idea greatly appreciated. Jean-Charles Quillet

2 4

Fwd: [naive] relationship between deadline_timer and io_service
by Ernest Galbrun 08 Jul '10

08 Jul '10

Dear Boost community, I have a rather simple question (some would say dumb) : I have been using the deadline_timer in asio library for a couple of hours, but I don't get why it is associated with an io_service (in fact, I don't get why this is in this library rather than in the date_time or timer library). I know it may seem trivial, but it is not to me, and I am worried I am missing something. regards, Ernest Galbrun.

2 1

Recursive variant problem
by Timothy Madden 08 Jul '10

08 Jul '10

Hi I use the following type in my application: boost::make_recursive_variant < boost::tuple < std::basic_string<TCHAR>, // id std::basic_string<TCHAR>, // name std::basic_string<TCHAR>, // desc std::basic_string<TCHAR>, // type std::basic_string<TCHAR>, // value std::vector<boost::recursive_variant_> // childList > >::type However when I instantiate it and I try to populate (resize) the vector (member indexed 5 in the tuple, childList) I get: 'boost::recursive_variant_' : class has no constructors from Visual Studio 2008 SP1. It looks like the boost::recursive_variant_ type is not substituted with the type of the enclosing variant by the make_recursive_variant meta-function. Am I missing something ? Is this is bug ? I have also tried adding some more members to the variant, with no success. Thank you, Timothy Madden

4 9

[Serialization] Problem with compiling (something about assertion)
by Mailing Lists Controller 08 Jul '10

08 Jul '10

Hi, I'm new to this list. I tried to search something related to my problem but I found nothing (or at least, nothing I guess it's related to my problem) and, sincerly, I don't really know what to search for. I excuse if I made an already solved request. Anyway I have this problem: I'm trying to compile the demo_xml.cpp from the Serialization tutorial. I compiled the libraries with bjam, I use gcc 3.4.5 on MinGW 5.1.6 (windows 7). I use Eclipse 3.5 as IDE. I compiled and runned perfectly the text_archive version of the tutorial but if I include xml_iarchive.hpp or xml_oarchive.hpp I get the following error: ===========================================Start========================================= **** Build of configuration Debug for project TestVariBoost **** **** Internal Builder is used for build **** g++ -IC:\Users\blueangel\workspace\TestVariBoost\include -IC:\Program Files\boost/include -O0 -g3 -Wall -c -fmessage-length=0 -osrc\demo_xml.o ..\src\demo_xml.cpp C:/Program Files/boost/include/boost/archive/basic_xml_oarchive.hpp: In member function `void boost::archive::basic_xml_oarchive<Archive>::save_override(T&, int) [with T = const std::list<std::pair<bus_schedule::trip_info, bus_route*>, std::allocator<std::pair<bus_schedule::trip_info, bus_route*> > >, Archive = boost::archive::xml_oarchive]': C:/Program Files/boost/include/boost/archive/detail/interface_oarchive.hpp:63: instantiated from `Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) [with T = const std::list<std::pair<bus_schedule::trip_info, bus_route*>, std::allocator<std::pair<bus_schedule::trip_info, bus_route*> > >, Archive = boost::archive::xml_oarchive]' C:/Program Files/boost/include/boost/archive/detail/interface_oarchive.hpp:71: instantiated from `Archive& boost::archive::detail::interface_oarchive<Archive>::operator&(T&) [with T = std::list<std::pair<bus_schedule::trip_info, bus_route*>, std::allocator<std::pair<bus_schedule::trip_info, bus_route*> > >, Archive = boost::archive::xml_oarchive]' ..\src\demo_gps.hpp:271: instantiated from `void bus_schedule::serialize(Archive&, unsigned int) [with Archive = boost::archive::xml_oarchive]' C:/Program Files/boost/include/boost/serialization/access.hpp:118: instantiated from `static void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::xml_oarchive, T = bus_schedule]' C:/Program Files/boost/include/boost/serialization/serialization.hpp:74: instantiated from `void boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::xml_oarchive, T = bus_schedule]' C:/Program Files/boost/include/boost/serialization/serialization.hpp:133: instantiated from `void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::xml_oarchive, T = bus_schedule]' C:/Program Files/boost/include/boost/archive/detail/oserializer.hpp:148: instantiated from `void boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::xml_oarchive, T = bus_schedule]' ..\src\demo_xml.cpp:277: instantiated from here C:/Program Files/boost/include/boost/archive/basic_xml_oarchive.hpp:92: error: no matching function for call to `assertion_failed(mpl_::failed************boost::serialization::is_wrapper<const std::list<std::pair<bus_schedule::trip_info, bus_route*>, std::allocator<std::pair<bus_schedule::trip_info, bus_route*> > > >::************)' C:/Program Files/boost/include/boost/archive/basic_xml_oarchive.hpp:92: error: enumerator value for `mpl_assertion_in_line_92' not integer constant Build error occurred, build is stopped Time consumed: 1263 ms. ============================================End========================================= Really I don't understand which assertion I fail at compile time. At line 92 of basic_xml_oarchive.hpp a comment say that most probably the variable to be serialized the to be around a nvp wrapper but the demo do that (this way: "oa << BOOST_SERIALIZATION_NVP(s);"). What else can it be? Thank you for your time.

2 1

Newbie: Building boost with Visual Studio 2008
by David Aldrich 08 Jul '10

08 Jul '10

Hi I have a question about building boost 1.43 with Visual Studio 2008. I have performed the following steps: 1) Downloaded and extracted boost_1_43_0.zip to C:\boost_1_43_0. 2) Built bjam (using tools\jam\src\build.bat). 3) Ran bjam in C:\boost_1_43_0 bjam ran successfully but the resulting tree contains .obj files but not all .lib files (for example, the RegEx libs are missing). I then ran: bjam.exe install This created folder c:\Boost, which does contain all the libraries and successfully links with the RegEx example program in 'boost: Getting Started on Windows'. That article ('boost: Getting Started on Windows') does not specify that I should run bjam install. Why was 'install' necessary in my case? Now I do not know whether to use C:\boost_1_43_0, which contains the headers and documentation, or C:\Boost, which contains the headers and libraries, as boost root. Obviously, if I choose the former, I need to fix it's build process. I want a solution that I can recommend to our development team. Please can someone advise me what is best practice? Best regards David

3 6

How to get the behavior of make_recursive_variant ?
by Timothy Madden 08 Jul '10

08 Jul '10

Hello I am constructing a data structure with STL containers and tuples and containers ..., so all inner memebers/components are unnamed (tuples use only indexes for element access, and so do STL containers, if at all) At a certain point my structure is recursive as it needs to hold a tree of (variables and maps and lists of (variables and maps and lists of (...))) boost::make_recursive_variant< >::type can serve my purpose well, except that I do not need a variant in my structure, I just need the structure to be recursive. Is there a way to get the recursive-definition behavior of make_recursive_variant<>, without the variant ? Also I am curios: how is such a recursive definition possible ? How does make_recursive_variant implement it ? Thank you, Timothy Madden

3 3

Musings: how to best implement this? (N ranges)
by John Dlugosz 07 Jul '10

07 Jul '10

Recall an earlier discussion of storing N ranges in a collection. Boost.Assign looks good, but is inefficient. I'm thinking of doing the same thing using some compile-time metaprogramming. I think Fusion offers the tools I need, to have part metaprogram and part runtime. Suppose my syntax is is: vector<whatever> vec= cat(R1)(R2)(begin1,end1)(R4); for any number of parameters where each application of operator() can contain a Range-concept-supporting object or two parameters that are a pair of iterators. The function call cat(R1) kicks it off, and each subsequent operator() adds to the Fusion sequence of ranges. I'm fighting back confusion as to the meta/regular boundary, so any help is appreciated at this point. So, the meta-ness is that the result of the chain is a single object without the runtime baggage needed to handle the heterogeneous nature -- that's the advantage, right? But then the run-time side needs to actually accumulate the values, which should be streamlined via the optimizer. I need not just a list of types (MPL), but types holding values or references to values. So operator() "does" a run-time push_back and the return type is a metaprogram. I'm not sure what I'm doing yet, but that's what I'm trying to get. Finally, the conversion operator can see the whole thing and accumulate the sizes of the component ranges, pre-allocate the vector, and then iterate the Fusion sequence to process each range in the normal way. One sticking point in my mind is how to handle Ranges that are whole STL collections. In that case, I want to hold them by reference. But other kinds of ranges... will references work with Fusion collections? Will doing everything by reference optimize out OK, or do I need to use values to acheive that? Does Range have some metaprogramming property for "best way to pass this kind of range"? More advanced, down the road: For now, I can assume that all ranges are random-access and can handle the size generic function. Slightly better is to separate the code paths so random-access ranges are sized and other ranges are not, giving 0; then the pre-allocation will still help some, or be business as usual with no pre-allocation. But more advanced would be to pre-allocate the total size (of the remaining portion of the list) as far as it is known, after concatenating a range that didn't have an efficient size function. So, given a mixed list, it will reduce the amount of re-copying that is done. Not sure of the algorithm; point is, "do something" before or after a non-random-access range is processed. So, I want to make sure I don't paint myself into a corner, even if I don't add this functionality initially. Any suggestions (or code scraps!) are welcome. Thanks, --John ===== begin evil footer added by mailer gateway ===== TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

1 0

Best way to put N ranges into a new container?
by John Dlugosz 07 Jul '10

07 Jul '10

I was originally contemplating writing something that took some number of Range arguments and push_back'ed onto a container. Where all of them are Random Access Ranges, it can count the elements first and reserve once. Otherwise, it just concats one range at a time. Maybe could be a bit smarter, but you get the idea. But reading through the Range docs, I'm wondering now if a better approach would be a Range Adaptor that could make a concatenated "view" (to use MPL's terminology) of all of the components put together. Does something like that already exist? Thanks, --John (footer not my idea) TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

2 4