March 2010 - Boost-users - lists.preview.boost.org

Re: [Boost-users] [Serialization] Strange giant warning
by Avi Bahra 11 Mar '10

11 Mar '10

This is caused by a bug in the boost serialisation, well at least in 1.39 Where is assumes that shared ptr must be polymorphic I have already reported a similar problem. i.e >>... boost_1_39_0/boost/ >>serialization/extended_type_info_typeid.hpp", line >> 88: >> warning #2414-D: delete of pointer to incomplete class >> BOOST_STATIC_WARNING(boost::is_polymorphic<T>::value); >> ^detected during: >> instantiation of "const boost::serialization::extended_type_info >> *boost::serialization::extended_type_info_typeid<T>::get_derived_extended_type_info(const >> T &) const [with T=Concrete]" at line 92 of >> "/scratch/ma/emos/ma0/hpia64/boost/boost_1_39_0/boost/archive/shared_ptr_helper.hpp" >> >> >> It looks like if we are serialising via a base ptr, and the >> base class is serialising concrete data member via a shared ptr, >> it has assumed that the type must be polymorphic. This does >> not seem right to me ? The hacky way to stop your warning message would be add a dummy virtual function. Best regards, Ta, Avi

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Regex alternation in xpressive
by Surya Kiran Gullapalli 11 Mar '10

11 Mar '10

Hello all, I'm trying to match ordinal numbers (1st, 2nd, 3rd, 4th etc) like this. *xpr::as_xpr ("Some Text") * * >> xpr::repeat<1, 2>(_d) * * >> ("st"|"nd"|"rd"|"th") ;* Compilation fails at 3rd line with the following error error C2296: '|' : illegal, left operand has type 'const char [3]' ; what am i missing ? did I give the construct correctly ? Thanks in advance, Surya

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BOOST_SERIALIZATION_BASE_OBJECT_NVP not convenient for template base class and XML archive
by Alain KOCELNIAK 11 Mar '10

11 Mar '10

template < class eArchive > void MtxAnsFunctionIntegerPipe::serialize( eArchive& aArchive, const unsigned int aVersion ) { aArchive & BOOST_SERIALIZATION_BASE_OBJECT_NVP( MtxAnmFunctionTpl<int> ) ; aArchive & BOOST_SERIALIZATION_NVP( mVariable ) ; } #define BOOST_SERIALIZATION_BASE_OBJECT_NVP(name) \ boost::serialization::make_nvp( \ BOOST_PP_STRINGIZE(name), \ boost::serialization::base_object<name >(*this) \ The stringized class name ("MtxAnmFunctionTpl<int>") generate a non valid XML tag name (due to < > ) There is no BOOST_SERIALIZATION_BASE_OBJECT_NVP2( type, tag) macro (as BOOST_CLASS_EXPORT_KEY2(class, key) for BOOST_EXPORT_CLASS_KEY(class) ). Such a macro is necessary to write things like : aArchive & BOOST_SERIALIZATION_BASE_OBJECT_NVP2( MtxAnmFunctionTpl<int>, "MtxAnmFunctionTplInt" ) ; In the next release ? Alain K.

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[function] dynamic function factory
by Alexander Lamaison 11 Mar '10

11 Mar '10

I'm trying to write a little wrapper round Windows GetProcAddress (dlsym equivalent?) that takes a function name by string, loads it dynamically and returns it as a boost::function. I'm having trouble getting my code to accept the same type of signatures as boost::function. E.g.: template<typename Signature> boost::function<Signature> proc_address( hmodule hmod, const std::string& name) { return boost::function<Signature>(GetProcAddress(hmod, name.c_str()); } Where GetProcAddress returns a int (*)() which you cast to the function signature you're expecting. The problem is that when I call: boost::function<int (int)> func; func = proc_address<int (int)>(hmod, "GetKeyboardInfo"); The compiler (MSVC 2005) complains about a ) after the int: error C2144: syntax error : 'int' should be preceded by ')' error C2563: mismatch in formal parameter list Am I trying to reuse boost::function the wrong way? I also tried making a functor instead but I have no idea what to put as the parameter list for operator(): template<typename Signature> class dynamic_function { public: dynamic_function(hmodule hmod, const std::string& name) : m_func(GetProcAddress(hmod, name.c_str())) {} operator()(...what goes here?...) { return m_func( ... what ... ); } private: boost::function<Signature> m_func; }; Any help is greatly appreciated. Alex

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integer constant too large for 'long' type
by David Kaplan 11 Mar '10

11 Mar '10

I'm having problems compiling this line of code on a 32bit system: boost::uniform_int<uint64_t> r(0,0xffffffffffffffff); compile-time error: "integer constant too large for 'long' type" compiled fine on my 64 bit machine. Also sizeof(uint64_t) on both machines is correct at 8 bytes (typedef'd as long long int on the 32bit machine). Any ideas?

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Boost.Asio chat example chat_client have 3 connections, what other 2 connections doing?
by l.jay Yuan 11 Mar '10

11 Mar '10

Boost.Asio chat example chat_client have 3 connections, what other 2 connections doing? Builded on WinXP. The implementation is strange.

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I'm creating an abstraction layer to work with C++, thought you might be interested
by Alan Tennant 10 Mar '10

10 Mar '10

I'm creating an abstraction layer to work with C++, thought you might be interested. Attached are the files required to use it. What it does should be apparent by reading from the top of main () and running the code, you might have to redirect the 4 #includes if you set up your directory structure differently from me. Note stuff.h only contains one function that is required. The program uses an object called obj to achieve the things it does, it does not add this functionality into the bottom level of C++. The key concepts of an obj include: Access members of objects using std::string's Strings can be transferred and stored a lot more easily than types. They can also be combined more easily, a trivial example is ".toString" being made of two parts. Finally they can easily be used as parameters so a function could take some data and member names as parameters. Individual obj members can be added and removed one at a time. One member function can easily be used by several different types. A function can look at aspects of the object it belongs to in order to work out how to behave without any problems or inconsistencies created by the underlying workings of C++. There is no need for all the empty (or otherwise meaningless) member functions that occur near the top of the tree in programs with lots of inheritance, although inheritance possibilities work differently the same sorts of results can be achieved just as easily with less code. CSS like parameters with names and values where any number of them can be used without having to specify the information in advance. Uses boost::any's extensively but you don't have to wrap and unwrap them yourself, less needing to repeat and know definite information about types all the time. Little difference between accessing different types of members such as objects or functions. Want obj's to behave in a fundamentally different way, write members yourself for object without having to edit my files and add them to obj's you create. I'm sure some of this is possible in other ways and put into code as you need it instead of being one big chunk but I think this abstraction layer is useful. I could also use #defines to simplify and enhance the feel of writing code for the user, for example adding some symbols to represent key features instead of having to write a whole word between .'s. It's not as great as it could be at the moment. I think it does everything by copy making it slow and making it so you can't change members when you access them, I wish for it to do everything by pointer to new memory is such a way as it has the Java feal of doing everything the fast way without having to think about it, it could even be smart enough to notice that bools are not efficient this way. I'm not sure how I will fix these things regarding things like how "template <typename T*>" works. Also when you do have to use normal types it might be hard to implement template functions on the obj functions you write. later I will implement removing a member, setting up a type containing various members, more easily creating objects with lots of miscellaneous members (using only one line of code) etc... p.s. I don't have lots of time at the moment to implement due to other commitments, if you like this consider helping with some of it.

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[proto] const-ness of references
by Manjunath Kudlur 10 Mar '10

10 Mar '10

>From reading the documentation, I understand that expressions and objects that are wrapped in proto::terminal<> are held by reference. In the following code, in the "assign" grammar, I match proto::terminal<Var<proto::_> > and call _assign on proto::_value. As expected, a reference to the object held in the terminal gets passed to the callable transform, and I can assign some value to it. template<typename VT> struct Var { VT value; void assign(const VT v) { value = v; } }; struct _assign : proto::callable { typedef void result_type; template<typename VT> result_type operator()(Var<VT> &var) const { var.assign(20); } }; struct assign : proto::or_< proto::when<proto::terminal<Var<proto::_> >, _assign(proto::_value)> > {}; typedef proto::terminal<Var<int> >::type int32_; int main() { int32_ a,b,c; assign()(a); std::cout << proto::value(a).value << std::endl; } Now, I add the following rules to assign grammar : struct assign : proto::or_< proto::when<proto::terminal<Var<proto::_> >, _assign(proto::_value)>, proto::when<proto::assign<proto::terminal<Var<proto::_> >, proto::literal<proto::_> >, _assign(proto::_value(proto::_left), proto::_value(proto::_right))>, proto::when<proto::function<proto::terminal<Var<proto::_> >, proto::literal<proto::_> >, _assign(proto::_value(proto::_left), proto::_value(proto::_right))> > {}; and the following operator() overload to _assign : template<typename VT> result_type operator()(Var<VT> &var, const VT val) const { var.assign(val); } I can merrily call assign()(a=10) and I get the expected behaviour. But when I call assign()(a(20)), I get a compilation error saying that there is no match for operator()(const Var<int> &, const int &). Why is that when I call proto::_value(proto::_left) on a proto::function expression, a *const* reference gets passed to the transform? Did I miss some part of the documentation where this is explained? Manjunath

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template concept question
by Alan Tennant 10 Mar '10

10 Mar '10

I was reading about boosts concepts and I thought. Can I ask inside a template function if a member exists on a parameter of the function. For example. template <typename T> void func(T in) { exists(in, foo); } Where the "exists" line would return true if "in" had a member "foo" otherwise false.

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[Gil new_io] Some questions and remarks
by Olivier Tournaire 10 Mar '10

10 Mar '10

Hi all, I have just checkout gil-contributions svn repo ( http://code.google.com/p/gil-contributions/) in order to test new_io in which I am really interested. Thank you for this very usefull job! I have however some remarks and questions about some compilation issues. 0) The code seems to have been written and tested on Windows. Am I right (see my remarks thereafter)? For ex., why do you use "\\" in paths (paths.hpp) and not "/"? 1) Which Boost version is required? I first tried with 1.40, but it did not work because of missing accessors in boost::gil::variant (index() and bits()). Did they appear in 1.41 or 1.42? With 1.42, this issue is solved. 2) While compiling tests, I ran into some issues. I am running the code on an Ubuntu 9.10, with g++-4.3.4. I was able to fix some of them, but others are still problematic: 2.1) For each test, I have to add at the beginning the 2 following lines: #define BOOST_TEST_DYN_LINK #define BOOST_TEST_MODULE my application tests It probably comes from my little knowledge of boost unit_test_framework. Could you explain? 2.2) For each test, the compiler gave the following error: /usr/local/include/boost/gil/extension/io_new/detail/dynamic_io_new.hpp:75: error: there are no arguments to ‘io_error’ that depend on a template parameter, so a declaration of ‘io_error’ must be available I simply add in *[...]/detail/dynamic_io_new.hpp* an unclude directive at the beginning of the file : #include <boost/gil/extension/io/io_error.hpp>. Still do not understand how it can work wihtout this ... 2.3) I had a similar error with *[...]/formats/bmp/read.hpp*: /usr/local/include/boost/gil/extension/io_new/formats/bmp/read.hpp:833: error: there are no arguments to ‘get_info’ that depend on a template parameter, so a declaration of ‘get_info’ must be available I simply changed line 833 from get_info() to parent_t::get_info(). Now works. 2.4) Some typename are missing (still do not know how visual can infer types ...): - [...]/formats/jpeg/read.hpp, line 336: *typename*Image::view_t - [...]/formats/bmp/is_allowed.hpp, line 73: *typename*View::value_type - [...]/formats/pnm/read.hpp, line 419: *typename* Image::view_t Everything works with these changes. 2.5) png_read_test failed. Obviously, this is a portability issue. PNG filenames for testing are uppercase, while they are lowercase in the test code. I think that is also missing in the code the path to png files. For example, in basic_format_test, instead of test_file< gray1_image_t >( "basn0g01.png" ); it soulhd be: test_file< gray1_image_t >(* png_in + "BASN0G01.PNG"* ); I did not rename all files, so I am unable to try the test. 2.6) Some tests fail to compile or link. Here are the errors: - *all_formats_test.cpp*: In file included from /usr/include/png.h:481, from /usr/local/include/boost/gil/extension/io_new/png_tags.hpp:23, from /usr/local/include/boost/gil/extension/io_new/png_read.hpp:22, from /usr/local/include/boost/gil/extension/io_new/png_all.hpp:22, from /home/olivier/work/dev/lib/gil-contributions-read-only/gil_2/libs/gil/io_new/test/all_formats_test.cpp:7: /usr/include/pngconf.h:335: error: expected constructor, destructor, or type conversion before ‘.’ token /usr/include/pngconf.h:336: error: ‘__dont__’ does not name a type - *pnm_reads_test.cpp*: pnm_read_test.cpp.o: In function `pnm_test::read_header_test::test_method()': pnm_read_test.cpp:(.text+0x24c0): undefined reference to `boost::gil::pnm_image_type::_color_asc' collect2: ld returned 1 exit status Do not really understand since _color_asc is a typedef defined in pnm_tags.hpp ... - *jpeg_old_test.cpp* (sorry for the message ...): /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp: In function ‘typename BinaryOp::result_type boost::gil::detail::apply_operation(const boost::gil::variant<Types>&, const Info&, BinaryOp) [with Types1 = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, Info = boost::gil::image_write_info<boost::gil::jpeg_tag, boost::gil::detail::no_log>, BinaryOp = boost::gil::detail::dynamic_io_fnobj<boost::gil::detail::jpeg_write_is_supported, boost::gil::detail::writer<boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>, boost::gil::jpeg_tag, boost::gil::detail::no_log> >]’: /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:283: instantiated from ‘void boost::gil::detail::dynamic_image_writer<Device, boost::gil::jpeg_tag, boost::gil::detail::no_log>::apply(const boost::gil::any_image_view<Views>&, const boost::gil::image_write_info<boost::gil::jpeg_tag, boost::gil::detail::no_log>&) [with Views = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, Device = boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>]’ /usr/local/include/boost/gil/extension/io_new/detail/write_view.hpp:302: instantiated from ‘void boost::gil::write_view(Device&, const boost::gil::any_image_view<Types2>&, const boost::gil::image_write_info<FormatTag, Log>&, typename boost::enable_if<typename boost::mpl::and_<typename boost::gil::detail::is_output_device<IODevice>::type, typename boost::gil::is_format_tag<FormatTag>::type, mpl_::bool_<true>, mpl_::bool_<true>, mpl_::bool_<true> >::type, void>::type*) [with Device = boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>, Views = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, FormatTag = boost::gil::jpeg_tag, Log = boost::gil::detail::no_log]’ /usr/local/include/boost/gil/extension/io_new/detail/write_view.hpp:357: instantiated from ‘void boost::gil::write_view(const String&, const boost::gil::any_image_view<Types2>&, const boost::gil::image_write_info<FormatTag, Log>&, typename boost::enable_if<typename boost::mpl::and_<typename boost::gil::detail::is_supported_path_spec<P>::type, typename boost::gil::is_format_tag<FormatTag>::type, mpl_::bool_<true>, mpl_::bool_<true>, mpl_::bool_<true> >::type, void>::type*) [with String = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, Views = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, FormatTag = boost::gil::jpeg_tag, Log = boost::gil::detail::no_log]’ /usr/local/include/boost/gil/extension/io_new/jpeg_io_old.hpp:169: instantiated from ‘void boost::gil::jpeg_write_view(const String&, const View&, int) [with String = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, View = boost::gil::any_image_view<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0> >]’ /home/olivier/work/dev/lib/gil-contributions-read-only/gil_2/libs/gil/io_new/test/jpeg_old_test.cpp:98: instantiated from here /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:243: error: invalid initialization of non-const reference of type ‘boost::gil::variant<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0> >::base_t&’ from a temporary of type ‘boost::gil::variant<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0> >::base_t’ /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:213: error: in passing argument 1 of ‘typename Op::result_type boost::gil::detail::apply_operation_base(Bits&, size_t, const Info&, Op) [with Types = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, Info = boost::gil::image_write_info<boost::gil::jpeg_tag, boost::gil::detail::no_log>, Bits = boost::gil::variant<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0> >::base_t, Op = boost::gil::detail::dynamic_io_fnobj<boost::gil::detail::jpeg_write_is_supported, boost::gil::detail::writer<boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>, boost::gil::jpeg_tag, boost::gil::detail::no_log> >]’ /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:243: error: return-statement with a value, in function returning 'void' Apart png_read_test and its case sensitive problem, all compiled and linked tests run successfully. This is a really good new! However, could you please help regarding the issues above? Please note that if you are intersted in a Linux developper/tester for gil, I am wiling to do some jobs ... Best regards, Olivier

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