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[accumulators] Is there a reset function yet?
by Tim Odenthal 21 May '10

21 May '10

Hi! I just discovered this nice functionality in boost, but while trying something as simple as calculating a mean from a set of numbers, I hit a strange drawback: It seems to be impossible to use the same accumulator again for a different set of numbers, because I cannot clear/ reset it. I found some old (ok, March 2009) discussions about this, but nothing in the documentation. By the way, does the accumulator do something to prevent an overflow when I add up everything into one variable? And does it prevent a loss of precision, when at a late stage the variable I sum everything into is very big, but the thing I add is very small? Maybe it would be a good idea to mention this in the documentation, as well... Many thanks in advance for any help Tim

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[msm] submachine interaction
by Gordon Smith 21 May '10

21 May '10

Hello - I've created a state machine in MSM successfully, but cannot figure out how to interact with a submachine state object. Using the tutorial machine in "Defining a submachine", can a playlist be provided to Playing? I'd like to call a constructor, or a 2 stage init function of Playing, but haven't figure out how. I could use the "FSM" parameter of the on_entry method of the submachine to pull the playlist, but it appears that FSM is the submachine itself (Playing), not the containing machine (Player) as it is for regular states. Thanks for you help, Gordon Smith

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Variant bool bug
by Robin 21 May '10

21 May '10

Hi When I add a bool into the variant, the get int version fails (VC2008 SP1, boost 1.42.0, sorry earlier was mentioning wrong version 1.37.0) typedef boost::variant <bool, int, string> VariantType; VariantType variant; variant = "hello world"; string stringTest = boost::get <string> (variant); cout << stringTest.c_str () << endl; variant = 5; int intTest = boost::get <int> (variant); // Fails cout << intTest << endl; Robin

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Variant bool bug
by Robin 21 May '10

21 May '10

Hi When I add a bool into the variant, the get int version fails (VC2008 SP1, boost 1.37) typedef boost::variant <bool, int, string> VariantType; VariantType variant; variant = "hello world"; string stringTest = boost::get <string> (variant); cout << stringTest.c_str () << endl; variant = 5; int intTest = boost::get <int> (variant); // Fails cout << intTest << endl; Robin

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recursive variant with mpl::vector
by Surya Kiran Gullapalli 21 May '10

21 May '10

Hello all, I'm trying to create a recursive variant over an MPL vector.<http://?shva=1#drafts/128ba01f42cb2169> attached is the code. I'm trying to add a templated function isType, which will return true if the type stored in variant is the type queried for or false otherwise. This doesn't work for recursive types. In the example, I expect the program outputs "Map Type" because the type stored in the variant is a map. but it says the type is not map. The problem is mpl::contains returns false for map type. (The type stored in mpl vector is boost::recursive_wrapper< map ... >, where as, I'm querying for map...). what is the way forward from here. Thanks, Surya.

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Re: [Boost-users] unable to build boost graph 1.43 with gcc 3.4.5 (Adam Spargo)
by Vial, Florent 21 May '10

21 May '10

>Have you set your include path correctly? >-I"." >-I"libs/graph/src" >seems unlikely???? I ran ./bootstrap.sh ./bjam --build-dir="/tmp/boost_143.build.gcc34" threading=multi link=static runtime-link=shared --prefix="/usr/local/boost1430-gcc34" --without-mpi --without-python --without-serialization --without-test --without-wave address-model=64 -d+2 --layout=tagged cxxflags="-fPIC" -j8 Running the same 2 commands also fails building boost 1.42 with the same error, but successfully builds boost 1.41. Florent A new star is born - ALEXA the most versatile digital camera system. Get all the latest information from arridigital.com and YouTube.----------------------------------------------------------------------- On Thu, 20 May 2010, Vial, Florent wrote: > Hi, > > trying to build boost 1.43 with gcc 3.4.5, i obtain following error: > > "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall > -pthread -m64 -fPIC -DBOOST_ALL_NO_LIB=1 -DNDEBUG -I"." > -I"libs/graph/src" -c -o > "/tmp/boost_143.build.gcc34/boost/bin.v2/libs/graph/build/gcc-3.4.5/re > le ase/address-model-64/link-static/threading-multi/graphml.o" > "libs/graph/src/graphml.cpp" > ./boost/property_tree/detail/xml_parser_read_rapidxml.hpp: In function > `void > boost::property_tree::xml_parser::read_xml_internal(std::basic_istream > <t ypename Ptree::key_type::value_type, std::char_traits<typename > Ptree::key_type::value_type> >&, Ptree&, int, const std::string&) > [with Ptree = boost::property_tree::basic_ptree<std::string, > std::string, std::less<std::string> >]': > ./boost/property_tree/xml_parser.hpp:52: instantiated from `void > boost::property_tree::xml_parser::read_xml(std::basic_istream<typename > Ptree::key_type::value_type, std::char_traits<typename > Ptree::key_type::value_type> >&, Ptree&, int) [with Ptree = > boost::property_tree::ptree]' > libs/graph/src/graphml.cpp:49: instantiated from here > ./boost/property_tree/detail/xml_parser_read_rapidxml.hpp:108: error: > non-constant `(((int)f_c) | 3072)' cannot be used as template argument > ./boost/property_tree/detail/xml_parser_read_rapidxml.hpp:108: error: > no matching function for call to > `rapidxml::xml_document<char>::parse(char*)' > ...skipped > <p/tmp/boost_143.build.gcc34/boost/bin.v2/libs/graph/build/gcc-3.4.5/r > el > ease/address-model-64/link-static/threading-multi>libboost_graph-mt.a( > cl > ean) for lack of > <p/tmp/boost_143.build.gcc34/boost/bin.v2/libs/graph/build/gcc-3.4.5/r > el ease/address-model-64/link-static/threading-multi>graphml.o... > ...skipped > <p/tmp/boost_143.build.gcc34/boost/bin.v2/libs/graph/build/gcc-3.4.5/r > el > ease/address-model-64/link-static/threading-multi>libboost_graph-mt.a > for lack of > <p/tmp/boost_143.build.gcc34/boost/bin.v2/libs/graph/build/gcc-3.4.5/r > el ease/address-model-64/link-static/threading-multi>graphml.o... > ...skipped <pstage/lib>libboost_graph-mt.a for lack of > <p/tmp/boost_143.build.gcc34/boost/bin.v2/libs/graph/build/gcc-3.4.5/r > el > ease/address-model-64/link-static/threading-multi>libboost_graph-mt.a... > ...failed updating 1 target... > > any workaround coming to mind ? > > Thank you, > Florent Arnold & Richter Cine Technik GmbH & Co. Betriebs KG Sitz: Munchen - Registergericht: Amtsgericht Munchen - Handelsregisternummer: HRA 57918 Personlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH Sitz: Munchen - Registergericht: Amtsgericht Munchen - Handelsregisternummer: HRB 54477 Geschaftsfuhrer: Franz Kraus; Dr. Martin Prillmann

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[serialization] Is it possible to force newer boost-serialization to be compatible with older versions?
by Mariusz Wojtysiak 21 May '10

21 May '10

Hello, I implementing client-server application. Data sent between sites are serialized using boost-serialization as text archive. Unfortunately very often both client and server work on different operating systems and may be compiled with different boost versions :- ( I noticed that when boost-library versions are different on server and client, then archive_exception is thrown with message ""unsupported version". Is there a way to force serialization library to be compatible with older versions, e.g. by calling: archive.set_library_version() ? Regards, Mariusz Wojtysiak

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Re: [Boost-users] boost/numeric/ublas/matrix_sparse.hpp does not play well with RICE
by John O. Woods 21 May '10

21 May '10

I attempted to compile this -- #ifdef ValueType # undef ValueType #endif #ifdef key_equal # undef key_equal #endif #include <boost/unordered_map.hpp> int main() { return 0; } -- but no luck, same set of errors. Steven: I have preprocessor output, but no clue what to do with it. It's quite long. Thanks for your continued assistance, both of you. John

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Re: [Boost-users] [iostreams]Can I write data directly to the device of a stream?
by 鑫炜廖 21 May '10

21 May '10

BTW, what's the differences between stream and stream_buffer, filtering_stream and filtering_streambuf besides different base classes they derived from ? Their members look all the same...

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Re: [Boost-users] boost/numeric/ublas/matrix_sparse.hpp does not play well with RICE
by John Woods 21 May '10

21 May '10

The first error, with matrix_sparse, is 4.2.1 and 4.4.3 (two machines, one karmic and the other lucid). The unordered_map error I can confirm with 4.2.1, and shall try 4.4.3 later. How does one check preprocessor output? Many thanks, John

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