- Boost-users - lists.boost.org

[boost-users] [bind][function] - too many copies
by Lorimer, Stephen 08 Oct '10

08 Oct '10

For a given member function of the form void foo::f0(), passing this to boost bind results in the class instance being copied 7 times. Storing the result of bind in boost function incurs another 11 copies (code and results are here: http://boost.codepad.org/6jBmoKuj) Using tr1::bind and function has slightly better results, but still not ideal: Doing just tr1::bind results in the class instance being copied 4 times. Storing the result of bind in tr1 function incurs another 3 copies (code and results are here: http://boost.codepad.org/w1EV6JBY) Am I right in saying this is because boost::bind uses normal templates while tr1::bind uses variadic templates? Either way this is not very efficient. Is there a way to improve this? ---------------------------------------------------------------------- This message w/attachments (message) is intended solely for the use of the intended recipient(s) and may contain information that is privileged, confidential or proprietary. If you are not an intended recipient, please notify the sender, and then please delete and destroy all copies and attachments, and be advised that any review or dissemination of, or the taking of any action in reliance on, the information contained in or attached to this message is prohibited. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Sender. Subject to applicable law, Sender may intercept, monitor, review and retain e-communications (EC) traveling through its networks/systems and may produce any such EC to regulators, law enforcement, in litigation and as required by law. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or free of errors or viruses. References to "Sender" are references to any subsidiary of Bank of America Corporation. Securities and Insurance Products: * Are Not FDIC Insured * Are Not Bank Guaranteed * May Lose Value * Are Not a Bank Deposit * Are Not a Condition to Any Banking Service or Activity * Are Not Insured by Any Federal Government Agency. Attachments that are part of this EC may have additional important disclosures and disclaimers, which you should read. This message is subject to terms available at the following link: http://www.bankofamerica.com/emaildisclaimer. By messaging with Sender you consent to the foregoing.

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Boost Logos: proposed high constrast logo
by Alfredo Correa 08 Oct '10

08 Oct '10

Hi all, In my opinion there should be a high contrast version of the Boost logo . (by that I mean either black and white or high contrast with very mild gradients on white background). Particularly I am talking about the three hexagons icon. As an example, the first attachment here has the official logo in SVG format. Because of the background gradient and the gradient fill of the hexagon it is not *obvious* how to convert this to high contrast. What should be replaced by black (or solid blue)? the hexagon filling? the hexagon borders? the background? A possible high contrast logo is attached in the second file. By no means official or the best option, it is just an possibility, maybe the simplest one. *Just an example*. Note that even the darkest blue used in the gradient of the official logo is not enough to contrast with white, so I used a darker blue. The reason I think a high contrast logo is the following: If you want to have a document printing quality (or high quality PDF) you need a vector format. If the printing or visualization is done in black and white, the logo should have high contrast otherwise the appearance will be very device dependent. While everyone should take care in printing in good devices having a logo that is barely visible in black/white/grey printing in some devices is not acceptable. As a test for what makes a high contrast logo a good one, just try printing and small version (one centimeter square) of the logo in a black and white laser printer with random text around it and you will see the problem with the low contrast original logo. It will appear like a grey blob at best. Please this thread is not about a new logo design just an adaptation of the existing one. This thread is not be related with the "Powered by" logo discussion Alfredo PS: the attachments are Inkscape SVG.

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[statechart] Unhandled events
by Oleg Smolsky 07 Oct '10

07 Oct '10

Hey there, I've been using SC for a while and something has been bugging me - given a state machine with: OuterSt, OneSt and TwoSt as well as OneEv and TwoEv that are handled by OneSt and TwoSt respectively, it is possible to send a wrong event to either of the last two states. Such an "unhandled" event will be forwarded to OuterSt and then quietly eaten. My question is as follows - is it possible to define some kind of "catch all" handler in the OuterSt? I have already fixed a tricky bug in my code where a submitted event was lost, and wonder if there is a simple way to handle these situations? I can certainly add a custom_reaction<>(X) for each possible event to the OuterSt and catch issues that way, but that's far from ideal. Any suggestions would be appreciated. P.S. perhaps a compromise solution would be to add something like this to OuterSt: sc::bug<OneEv> sc::bug<TwoEv> but that would effectively limit handling to issuing an assert(false)... Thanks, Oleg.

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[boost-spirit qi] internal copies
by Ovanes Markarian 07 Oct '10

07 Oct '10

Hello *, I think this is more the question to spirit devlopers. I would like to know how spirit internally maintains the parsed data? Here is an example of what I mean. I have to parse some byte sequence represented as hex pairs: 00 ce ab 00 de ad be ef ... If I use the parser like this: boost::spirit::qi::uint_parser<unsigned char, 16, 2,2> hex_byte; std::string str("..."); std::vector<byte_t> vec; iter_type curr=str.begin(), end=str.end(); bool r=phrase_parse(curr, end, +hex_byte, space, vec); Is vec going to be copied somewhere inside of qi? Or are the bytes directly appended to the vec? I would like to reserver some space for the maximum possible input and avoid additional internal copies inside of qi... How does the behaviour changes std::vector<byte_t> is part of the fusion::map like fusion::map < fusion::pair<tag1, string> , fusion::pair<tag2, string> ... , fusion::pair<tagN, std::vector<byte_t> > > data_item; Are the fields of the map used directly while parsing, or are there some temporaries, which will be first created (somewhere inside qi core) and filled with data and afterwards assigned to the corresponding map field? Many thanks for the gread lib! Ovanes

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[boost::math]binomial_coefficient compile error
by Suresh Kumar 07 Oct '10

07 Oct '10

Hi this code gives a compile error. #include <iostream> #include <boost/math/special_functions/binomial.hpp> using namespace std; int main(){ cout << boost::math::binomial_coefficient(10,1) << endl; } binom.cpp:8: error: no matching function for call to ‘binomial_coefficient(int, int)’ what is that I am missing? thanks suresh -- R Suresh Kumar, http://www.ee.ucr.edu/~sramachandranna Sarve bhavantu sukinaha (May everyone be happy) Sarve santu niramiyaha (May everyone be without affliction) Sarve bhadrani pashyantu (May everyone see only goodness) Ma kashchit dukha bhak bhavet (Let none be the victim of suffering)

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[Python] Unable to use static library of boost.python due to undefined symbols
by Philipp Münzel 06 Oct '10

06 Oct '10

Hi folks, I'm trying to build a python extension with statically linked libboost_python on Linux. I built boost_python with ./bjam -q --layout=system --with-python toolset=gcc variant=release link=static threading=multi runtime-link=static which results in a 700kb libboost_python.a Then I try to build the hello world example located at /libs/python/example/tutorial but I fail, because their remain undefined symbols, despite the fact I did define BOOST_PYTHON_STATIC_LIB. Heres what I did: $ cat hello.cpp // Copyright Joel de Guzman 2002-2004. Distributed under the Boost // Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt // or copy at http://www.boost.org/LICENSE_1_0.txt) // Hello World Example from the tutorial // [Joel de Guzman 10/9/2002] #include <boost/python/module.hpp> #include <boost/python/def.hpp> char const* greet() { return "hello, world"; } BOOST_PYTHON_MODULE(hello_ext) { using namespace boost::python; def("greet", greet); } $ g++ -I/usr/local/include -I/usr/include/python -DBOOST_PYTHON_STATIC_LIB -fpic -c -o hello.o hello.cpp $ g++ -shared -Wl,-soname,"libhello.so" -L/usr/local/lib -lboost_python -fpic -o libhello.so hello.o $ nm -u libhello.so U PyString_Type w _Jv_RegisterClasses U _Py_NoneStruct U _Unwind_Resume@@GCC_3.0 U _ZN5boost6python6detail11init_moduleEPKcPFvvE U _ZN5boost6python6detail12gcc_demangleEPKc U _ZN5boost6python6detail17scope_setattr_docEPKcRKNS0_3api6objectES3_ U _ZN5boost6python7objects15function_objectERKNS1_11py_functionE U _ZN5boost6python7objects21py_function_impl_baseD2Ev U _ZN5boost6python9converter19do_return_to_pythonEPKc U _ZN5boost6python9converter8registry5queryENS0_9type_infoE U _ZNK5boost6python7objects21py_function_impl_base9max_arityEv U _ZNK5boost6python9converter12registration25expected_from_python_typeEv U _ZTIN5boost6python7objects21py_function_impl_baseE U _ZTIPKc@@CXXABI_1.3 U _ZTIc@@CXXABI_1.3 U _ZTVN10__cxxabiv120__si_class_type_infoE@@CXXABI_1.3 U _ZTVN5boost6python7objects21py_function_impl_baseE U _ZdlPv@@GLIBCXX_3.4 U _Znwm@@GLIBCXX_3.4 U __cxa_atexit@@GLIBC_2.2.5 w __cxa_finalize@@GLIBC_2.2.5 U __cxa_guard_abort@@CXXABI_1.3 U __cxa_guard_acquire@@CXXABI_1.3 U __cxa_guard_release@@CXXABI_1.3 w __gmon_start__ U __gxx_personality_v0@@CXXABI_1.3 $ python >>> import libhello Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: ./libhello.so: undefined symbol: _ZNK5boost6python7objects21py_function_impl_base9max_arityEv The example works marvellous when using the shared lib of boost_python, but it has to be a static build for me. I found a mailing list entry from 2002 mentioning the static build of boost.python was broken, but that is for sure fixed by now, isn't it? Regards, Philipp

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[Fusion] How to join more than two sequences
by Clinton Mead 06 Oct '10

06 Oct '10

Hi All I've noticed the function "join" in the boost fusion library. However, it only joins two sequences. Was wondering whether there is (or can be easily made) a function that joins any number of sequences. For example: new_join(make_vector(1,2,3), make_vector(4,5), make_vector(6)) -> is the sequence 1,2,3,4,5,6 AND/OR (pass parameters in a sequence) new_join(make_vector(make_ vector(1,2,3), make_vector(4,5), make_vector(6))) -> is the sequence 1,2,3,4,5,6 I'd prefer both the first and second versions, but even one version would be ok. Thanks, Clinton

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[filesystem] V3 path::replace_extension() spans path components
by Timothy Madden 06 Oct '10

06 Oct '10

Hello It appears that in boost 1.44.0 filesystem V3 path("\Cristina.ADI\Local Settings").replace_extension(".png") just returns "\Cristina.png" instead of "\Cristina.ADI\Local Settings.png" Could this be fixed ? Thank you, Timothy Madden

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[proto]Compile issue on Sun Solaris 10, Sun Studio 12.2
by Sascha Ochsenknecht 06 Oct '10

06 Oct '10

Hello, I got an error from the Sun Studio 12.2 (CC 5.11) when trying to compile my sources. The error comes out of the Boost.Proto library (actually I'm doing something with Boost.Spirit and Boost.Spirit is using Boost.Proto ..., but I don't think that the problem is in the client code, it seems to come from the buggy compiler). I'm using Boost 1.43. This is what I got from the compiler: "...include/boost/proto/detail/decltype.hpp", line 343: Error: Partial specialization parameter V is not used in the arguments. "...include/boost/proto/transform/arg.hpp", line 287: Error: Partial specialization for boost::proto::_byval::result has identical arguments. "...include/boost/proto/extends.hpp", line 600: Error: type is not a member of boost::result_of<boost::proto::domainns_::default_domain>. "...include/boost/spirit/home/support/terminal.hpp", line 237: Where: While specializing "boost::proto::exprns_::extends<boost::proto::exprns_::expr<boost::proto::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::bin>, 0>, boost::spirit::terminal<boost::spirit::tag::bin>, boost::proto::domainns_::default_domain, 0>". (the following is talking about "include/boost/proto/detail/decltype.hpp", line 343) With g++ this code compiles without any problems and runs as expected. Searching around the internet, I got the following bug entry of the Sun Studio compiler: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6926895 It looks like a similar problem. The bug entry contains a small example which reproduces the compile error: template <typename T> struct test { T t; }; template <typename T, typename X> struct test<X T::*> { X T::* x; }; template <typename T> struct test2 {}; template <typename T, typename X> struct test2< test<X T::*> > { test<X T::*> xt; }; int main() { test<int> a; a.t = 1; int test<int>::* s = &test<int>::t; test<int test<int>::*> a2; a2.x = s; test2<test<int test<int>::* > > a3; a3.xt = a2; return a.*a3.xt.x; } $ CC example.C "example.C", line 4: Error: Partial specialization parameter T is not used in the arguments. The bug entry also provides a workaround which seems to work. Replace the template types with the following: template <typename T> struct helper { }; template <typename T> struct test2 : public test2< helper<T> > { }; template <typename T> struct test2<helper< T> > { } ; template <typename T, typename X > struct test2< helper<test<X T::* > > {test<X T::*> xt; }; I would like to try a similar workaround adapted to the Boost.Proto source code. I tried several things but since I'm not fully aware what is going on in the proto sources and what is the exact reason the compiler fails, I couldn't make it work so far. Does anybody had a similar problem or does anybody know how to adapt the Boost.Proto source to make the Sun compiler happy? BTW: For me it would be ok for now to patch my local Boost source files. Here is the snippet from proto/detail/decltype.hpp: //////////////////////////////////////////////////////////////////////////////////////////// // result_of_ is a wrapper around boost::result_of that also handles "invocations" of // member object pointers. template<typename T, typename Void = void> struct result_of_ : boost::result_of<T> {}; // THE FOLLOWING IS TROUBLE MAKER FOR THE SUN COMPILER -> template<typename T, typename U, typename V> struct result_of_<T U::*(V), typename enable_if_c<is_member_object_pointer<T U::*>::value>::type> { BOOST_STATIC_CONSTANT(bool, is_V_a_smart_ptr = 2 == sizeof(test_V_is_a_U<U>(&lvalue(make<V>())))); BOOST_STATIC_CONSTANT(bool, is_ptr_to_const = 2 == sizeof(test_ptr_to_const(BOOST_PROTO_GET_POINTER(U, make<V>())))); // If V is not a U, then it is a (smart) pointer and we can always return an lvalue. // Otherwise, we can only return an lvalue if we are given one. typedef typename mpl::eval_if_c< (is_V_a_smart_ptr || is_reference<V>::value) , mpl::eval_if_c< is_ptr_to_const , add_reference<typename add_const<T>::type> , add_reference<T> > , mpl::identity<T> >::type type; }; Thanks in advance, Sascha

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boost 1.44.0 undefined reference to boost::filesystem2::no_check
by Asif Fayyaz 06 Oct '10

06 Oct '10

Hi, I am compiling a very simple application using boost filesystem. However it is giving following error message: "undefined reference to `boost::filesystem2::no_check(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'" Here is the simple application source: --------------------------------Sample application source: #include <stdio.h> #include <boost/filesystem.hpp> int main() { std::string m_FileName(boost::filesystem::path("testfile1.txt", boost::filesystem::no_check).native_file_string()); printf("Testboost.....%s\n", m_FileName.c_str()); return 0; } -------------------------------- More Details: Libraries being used: libboost_filesystem-gcc41-mt-1_44.a libboost_system-gcc41-mt-1_44.a Boost version: 1.44.0 Boost was build using command: bjam --build-type=complete --layout=versioned Operating System: Linux CentOS5.2 Any help in this regard will be appreciated. Asif

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