April 2013 - Boost-users - lists.preview.boost.org

boost.log linker issue
by Jonathan Walker 22 Apr '13

22 Apr '13

Hello, I have previously successfully compiled and built the dynamic boost.log libraries with MSVC-8.0, along with a few test programs that were linking to the boost libs dynamically. The test program was built and ran fine. I have now built boost.log static libraries with MSVC-10.0 without issue, yet my test program is now failing to build when attempting to link statically. See attachment for specific errors. It seems as though the project is including the headers with the <dllimport> tag, though my MSVC-10.0 project does not have BOOST_ALL_DYN_LINK or BOOST_LOG_DYN_LINK macro defined. Is there some way I need to signal my project that I'm using boost.log statically? Thanks, Jonathan ________________________________ This e-mail and any attachments are confidential. If it is not intended for you, please notify the sender, and please erase and ignore the contents.

2 2

Interprocess cleanup
by Davies, John 22 Apr '13

22 Apr '13

I'm running unit tests using Boost::test that starts up Boost threads, shared memory, and message queues. There are multiple tests in the suite. While writing a test it can fail prematurely and leave behind shared memory and message queues. Then when I run the tests again I can have trouble with mutexes, etc that already exist. I am working under Windows but eventually will be moving to Linux. Is there some way (other than rebooting) to force a cleanup of all the system objects that are created in the background? Or even a way of determining what has outlived its usefulness? Thanks. ___________________________________ John Davies Contractor Home Respiratory Care Philips Home Healthcare Solutions 1740 Golden Mile Highway Monroeville, PA 15146 Email: john.davies(a)philips.com Fax: 724-387-4109 ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

1 0

boost::bind issues revisited
by Littlefield, Tyler 22 Apr '13

22 Apr '13

oHello all: I'm kind of at a loss here. It looks like ther'es an issue with boost::bind somewhere in the mess of 500 templates and 90 screens of errors and I don't know enough about the mess to untangle it. Any info would be awesome. First, the code: sgroup->AddEntry(new OlcStringEntry("name", "Sets the name of the object", OF_NORMAL, boost::bind(&StaticObject::GetName, _1), <159> boost::bind(&StaticObject::SetName, _1, _2))); the 159 I denoted is useful in the errors later. Now the rest of the code I'm using: typedef boost::function<std::string ()> StringGetter; typedef boost::function<void (const std::string&)> StringSetter; class IOlcEntry { protected: std::string _name; std::string _help; FLAG _flag; public: IOlcEntry(const std::string &name, const std::string &help, FLAG flag) { _flag = flag; _name = name; _help = help; } ~IOlcEntry() {} }; class OlcStringEntry:public IOlcEntry { protected: StringGetter _getter; StringSetter _setter; public: OlcStringEntry(const std::string &name, const std::string &help, FLAG flag, const StringGetter getter, const StringSetter setter) :IOlcEntry(name, help, flag) { _setter = setter; _getter = getter; } }; and here is the novel of errors: 02:45:56: Compiling staticObject.cpp. In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp: In instantiation of ‘R boost::_bi::list1<A1>::operator()(boost::_bi::type<R>, F&, A&, long int) [with R = std::basic_string<char>; F = boost::_mfi::cmf0<std::basic_string<char>, BaseObject>; A = boost::_bi::list0; A1 = boost::arg<1>]’: /usr/local/include/boost/bind/bind_template.hpp:20:59: required from ‘boost::_bi::bind_t<R, F, L>::result_type boost::_bi::bind_t<R, F, L>::operator()() [with R = std::basic_string<char>; F = boost::_mfi::cmf0<std::basic_string<char>, BaseObject>; L = boost::_bi::list1<boost::arg<1> >; boost::_bi::bind_t<R, F, L>::result_type = std::basic_string<char>]’ /usr/local/include/boost/function/function_template.hpp:132:42: required from ‘static R boost::detail::function::function_obj_invoker0<FunctionObj, R>::invoke(boost::detail::function::function_buffer&) [with FunctionObj = boost::_bi::bind_t<std::basic_string<char>, boost::_mfi::cmf0<std::basic_string<char>, BaseObject>, boost::_bi::list1<boost::arg<1> > >; R = std::basic_string<char>]’ /usr/local/include/boost/function/function_template.hpp:934:60: required from ‘void boost::function0<R>::assign_to(Functor) [with Functor = boost::_bi::bind_t<std::basic_string<char>, boost::_mfi::cmf0<std::basic_string<char>, BaseObject>, boost::_bi::list1<boost::arg<1> > >; R = std::basic_string<char>]’ /usr/local/include/boost/function/function_template.hpp:722:7: required from ‘boost::function0<R>::function0(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::_bi::bind_t<std::basic_string<char>, boost::_mfi::cmf0<std::basic_string<char>, BaseObject>, boost::_bi::list1<boost::arg<1> > >; R = std::basic_string<char>; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ /usr/local/include/boost/function/function_template.hpp:1069:16: required from ‘boost::function<R()>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::_bi::bind_t<std::basic_string<char>, boost::_mfi::cmf0<std::basic_string<char>, BaseObject>, boost::_bi::list1<boost::arg<1> > >; R = std::basic_string<char>; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ staticObject.cpp:159:44: required from here /usr/local/include/boost/bind/bind.hpp:243:60: error: no match for ‘operator[]’ in ‘a[boost::_bi::storage1<boost::arg<I> >::a1_<1>]’ /usr/local/include/boost/bind/bind.hpp:243:60: note: candidates are: In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp:170:27: note: template<class T> T& boost::_bi::list0::operator[](boost::_bi::value<T>&) const /usr/local/include/boost/bind/bind.hpp:170:27: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp:243:60: note: mismatched types ‘boost::_bi::value<T>’ and ‘boost::arg<1>()’ In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp:172:33: note: template<class T> const T& boost::_bi::list0::operator[](const boost::_bi::value<T>&) const /usr/local/include/boost/bind/bind.hpp:172:33: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp:243:60: note: mismatched types ‘const boost::_bi::value<T>’ and ‘boost::arg<1>()’ In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp:174:27: note: template<class T> T& boost::_bi::list0::operator[](const boost::reference_wrapper<T>&) const /usr/local/include/boost/bind/bind.hpp:174:27: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp:243:60: note: mismatched types ‘const boost::reference_wrapper<T>’ and ‘boost::arg<1>()’ In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp:176:76: note: template<class R, class F, class L> typename boost::_bi::result_traits<R, F>::type boost::_bi::list0::operator[](boost::_bi::bind_t<R, F, L>&) const /usr/local/include/boost/bind/bind.hpp:176:76: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind.hpp:22:0, from staticObject.cpp:2: /usr/local/include/boost/bind/bind.hpp:243:60: note: mismatched types ‘boost::_bi::bind_t<R, F, L>’ and ‘boost::arg<1>()’ /usr/local/include/boost/bind/bind.hpp:178:76: note: template<class R, class F, class L> typename boost::_bi::result_traits<R, F>::type boost::_bi::list0::operator[](const boost::_bi::bind_t<R, F, L>&) const /usr/local/include/boost/bind/bind.hpp:178:76: note: template argument deduction/substitution failed: /usr/local/include/boost/bind/bind.hpp:243:60: note: mismatched types ‘const boost::_bi::bind_t<R, F, L>’ and ‘boost::arg<1>()’ In file included from /usr/local/include/boost/bind/bind.hpp:29:0, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/bind/arg.hpp: In instantiation of ‘boost::arg<I>::arg(const T&) [with T = boost::arg<2>(); int I = 1]’: /usr/local/include/boost/bind/bind.hpp:313:9: required from ‘void boost::_bi::list2<A1, A2>::operator()(boost::_bi::type<void>, F&, A&, int) [with F = boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>; A = boost::_bi::list1<const std::basic_string<char>&>; A1 = boost::arg<1>; A2 = boost::arg<2>]’ /usr/local/include/boost/bind/bind_template.hpp:47:59: required from ‘boost::_bi::bind_t<R, F, L>::result_type boost::_bi::bind_t<R, F, L>::operator()(const A1&) [with A1 = std::basic_string<char>; R = void; F = boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>; L = boost::_bi::list2<boost::arg<1>, boost::arg<2> >; boost::_bi::bind_t<R, F, L>::result_type = void]’ /usr/local/include/boost/function/function_template.hpp:153:11: required from ‘static void boost::detail::function::void_function_obj_invoker1<FunctionObj, R, T0>::invoke(boost::detail::function::function_buffer&, T0) [with FunctionObj = boost::_bi::bind_t<void, boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>, boost::_bi::list2<boost::arg<1>, boost::arg<2> > >; R = void; T0 = const std::basic_string<char>&]’ /usr/local/include/boost/function/function_template.hpp:934:60: required from ‘void boost::function1<R, T1>::assign_to(Functor) [with Functor = boost::_bi::bind_t<void, boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>, boost::_bi::list2<boost::arg<1>, boost::arg<2> > >; R = void; T0 = const std::basic_string<char>&]’ /usr/local/include/boost/function/function_template.hpp:722:7: required from ‘boost::function1<R, T1>::function1(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::_bi::bind_t<void, boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>, boost::_bi::list2<boost::arg<1>, boost::arg<2> > >; R = void; T0 = const std::basic_string<char>&; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ /usr/local/include/boost/function/function_template.hpp:1069:16: required from ‘boost::function<R(T0)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::_bi::bind_t<void, boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>, boost::_bi::list2<boost::arg<1>, boost::arg<2> > >; R = void; T0 = const std::basic_string<char>&; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ staticObject.cpp:159:44: required from here /usr/local/include/boost/bind/arg.hpp:37:22: error: size of array is negative In file included from /usr/local/include/boost/bind/mem_fn.hpp:215:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/bind/mem_fn_template.hpp: In instantiation of ‘R boost::_mfi::mf1<R, T, A1>::call(U&, const void*, B1&) const [with U = const std::basic_string<char>; B1 = const std::basic_string<char>; R = void; T = BaseObject; A1 = const std::basic_string<char>&]’: /usr/local/include/boost/bind/mem_fn_template.hpp:179:42: required from ‘R boost::_mfi::mf1<R, T, A1>::operator()(const U&, A1) const [with U = std::basic_string<char>; R = void; T = BaseObject; A1 = const std::basic_string<char>&]’ /usr/local/include/boost/bind/bind.hpp:313:9: required from ‘void boost::_bi::list2<A1, A2>::operator()(boost::_bi::type<void>, F&, A&, int) [with F = boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>; A = boost::_bi::list1<const std::basic_string<char>&>; A1 = boost::arg<1>; A2 = boost::arg<2>]’ /usr/local/include/boost/bind/bind_template.hpp:47:59: required from ‘boost::_bi::bind_t<R, F, L>::result_type boost::_bi::bind_t<R, F, L>::operator()(const A1&) [with A1 = std::basic_string<char>; R = void; F = boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>; L = boost::_bi::list2<boost::arg<1>, boost::arg<2> >; boost::_bi::bind_t<R, F, L>::result_type = void]’ /usr/local/include/boost/function/function_template.hpp:153:11: required from ‘static void boost::detail::function::void_function_obj_invoker1<FunctionObj, R, T0>::invoke(boost::detail::function::function_buffer&, T0) [with FunctionObj = boost::_bi::bind_t<void, boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>, boost::_bi::list2<boost::arg<1>, boost::arg<2> > >; R = void; T0 = const std::basic_string<char>&]’ /usr/local/include/boost/function/function_template.hpp:934:60: required from ‘void boost::function1<R, T1>::assign_to(Functor) [with Functor = boost::_bi::bind_t<void, boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>, boost::_bi::list2<boost::arg<1>, boost::arg<2> > >; R = void; T0 = const std::basic_string<char>&]’ /usr/local/include/boost/function/function_template.hpp:722:7: required from ‘boost::function1<R, T1>::function1(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::_bi::bind_t<void, boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>, boost::_bi::list2<boost::arg<1>, boost::arg<2> > >; R = void; T0 = const std::basic_string<char>&; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ /usr/local/include/boost/function/function_template.hpp:1069:16: required from ‘boost::function<R(T0)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::_bi::bind_t<void, boost::_mfi::mf1<void, BaseObject, const std::basic_string<char>&>, boost::_bi::list2<boost::arg<1>, boost::arg<2> > >; R = void; T0 = const std::basic_string<char>&; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ staticObject.cpp:159:44: required from here /usr/local/include/boost/bind/mem_fn_template.hpp:156:53: error: no matching function for call to ‘get_pointer(const std::basic_string<char>&)’ /usr/local/include/boost/bind/mem_fn_template.hpp:156:53: note: candidates are: In file included from /usr/local/include/boost/bind/bind.hpp:25:0, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/ref.hpp:182:29: note: template<class T> T* boost::get_pointer(const boost::reference_wrapper<T>&) /usr/local/include/boost/ref.hpp:182:29: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind/mem_fn.hpp:215:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/bind/mem_fn_template.hpp:156:53: note: ‘const std::basic_string<char>’ is not derived from ‘const boost::reference_wrapper<T>’ In file included from /usr/local/include/boost/bind/mem_fn.hpp:25:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/get_pointer.hpp:20:23: note: template<class T> T* boost::get_pointer(T*) /usr/local/include/boost/get_pointer.hpp:20:23: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind/mem_fn.hpp:215:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/bind/mem_fn_template.hpp:156:53: note: mismatched types ‘T*’ and ‘std::basic_string<char>’ In file included from /usr/local/include/boost/bind/mem_fn.hpp:25:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/get_pointer.hpp:27:23: note: template<class T> T* boost::get_pointer(const std::auto_ptr<T>&) /usr/local/include/boost/get_pointer.hpp:27:23: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind/mem_fn.hpp:215:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/bind/mem_fn_template.hpp:156:53: note: ‘const std::basic_string<char>’ is not derived from ‘const std::auto_ptr<T>’ In file included from /usr/local/include/boost/bind/mem_fn.hpp:25:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/get_pointer.hpp:34:23: note: template<class T> T* boost::get_pointer(const std::unique_ptr<T>&) /usr/local/include/boost/get_pointer.hpp:34:23: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind/mem_fn.hpp:215:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/bind/mem_fn_template.hpp:156:53: note: ‘const std::basic_string<char>’ is not derived from ‘const std::unique_ptr<T>’ In file included from /usr/local/include/boost/bind/mem_fn.hpp:25:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/get_pointer.hpp:39:23: note: template<class T> T* boost::get_pointer(const std::shared_ptr<_Tp>&) /usr/local/include/boost/get_pointer.hpp:39:23: note: template argument deduction/substitution failed: In file included from /usr/local/include/boost/bind/mem_fn.hpp:215:0, from /usr/local/include/boost/mem_fn.hpp:22, from /usr/local/include/boost/bind/bind.hpp:26, from /usr/local/include/boost/bind.hpp:22, from staticObject.cpp:2: /usr/local/include/boost/bind/mem_fn_template.hpp:156:53: note: ‘const std::basic_string<char>’ is not derived from ‘const std::shared_ptr<_Tp>’ /usr/local/include/boost/bind/mem_fn_template.hpp:156:53: error: return-statement with a value, in function returning 'void' [-fpermissive] make: *** [staticObject.o] Error 1 Thanks in advance, -- Take care, Ty http://tds-solutions.net The aspen project: a barebones light-weight mud engine: http://code.google.com/p/aspenmud He that will not reason is a bigot; he that cannot reason is a fool; he that dares not reason is a slave.

3 4

thread/call_once compile error on trunk on my code
by Olaf Peter 21 Apr '13

21 Apr '13

Hello, my svn and compiler versions are: Path: . URL: http://svn.boost.org/svn/boost/trunk Repository Root: http://svn.boost.org/svn/boost Repository UUID: b8fc166d-592f-0410-95f2-cb63ce0dd405 Revision: 83985 Node Kind: directory Schedule: normal Last Changed Author: viboes Last Changed Rev: 83985 Last Changed Date: 2013-04-20 16:12:43 +0200 (Sat, 20 Apr 2013) $ LANG=en g++ --version g++ (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2) Copyright (C) 2011 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. and maybe the last changes $ svn log boost/thread/pthread/once_atomic.hpp ------------------------------------------------------------------------ r83466 | viboes | 2013-03-16 16:36:21 +0100 (Sa, 16. Mär 2013) | 1 Zeile Thread: add invoke when no variadic templates are available; adapt call_once. breaks my code now which is basically: ---8<--- namespace { struct id_string { static boost::once_flag flag; typedef std::map<int, std::string> map_type; ... static void do_init(token_id_string& self) { insert(self.m_map)(x, "y")(...) ; } std::string const& operator()(id::type id) const { boost::call_once(flag, &id_string::do_init, *this); map_iterator s = m_map.find(id); ... } }; id_string::map_type id_string::m_map; #ifdef BOOST_THREAD_PROVIDES_ONCE_CXX11 boost::once_flag id_string::flag; #else boost::once_flag id_string::flag = BOOST_ONCE_INIT; #endif } --->8--- The error is about /usr/local/include/boost/thread/detail/invoke.hpp: In function 'typename boost::enable_if_c<(! boost::is_member_function_pointer<Fp>::value), Ret>::type boost::detail::invoke(Fp&&, Args&& ...) [with Ret = void, Fp = void (*)({anonymous}::id_string&), Args = {{anonymous}::id_string}, typename boost::enable_if_c<(! boost::is_member_function_pointer<Fp>::value), Ret>::type = void]': /usr/local/include/boost/thread/pthread/once_atomic.hpp:127:9: instantiated from 'void boost::call_once(boost::once_flag&, Function&&, ArgTypes&& ...) [with Function = void (*)({anonymous}::id_string&), ArgTypes = {{anonymous}::id_string&}]' /home/olaf/work/token_ids.cpp:93:59: instantiated from here /usr/local/include/boost/thread/detail/invoke.hpp:406:65: error: invalid initialization of non-const reference of type '{anonymous}::id_string&' from an rvalue of type '{anonymous}::id_string' Is this intentionally or do I miss something? Thanks, Olaf

2 6

[serialization] counting the xml cost
by Michael Powell 20 Apr '13

20 Apr '13

Hello, Basically, I'd like to find out how well the boost serialization facilities handle Xml and to what degree, robustness, etc. I am counting the cost of serialization for our model. We'll need do some basic CRUD type operations on our model objects throughout our system, and I want to use a nicely loosely coupled solution. Xml is the thought at first; I've also considered a lightweight database like SQLite which transfers easily for patches, upgrades, and other transfers. Looking at the boost serialization facilities, one keyword was emphasized in the tech-agnostic serialization documentation. Tech meaning whether this is a binary file, text, JSON, Xml, whatever. The keyword being that serialization and load occur in the same order. Enter the desire for Xml. One common problem in .NET C# land, at any rate, is that reads are commonly known as being asymmetric from writes. That is, not guaranteed to happen in the same order, composition, whatever. That is, you may see attributes in one instance, where as in another the element might have been broken out. Such as: <myObject name="something" /> and <myObject><name>something</name></myObject> are technically the same. The serializer might scoff at that, but I'm not sure the W3C suggest otherwise. That's my loose understanding of the specification. Regards, Michael Powell

1 3

Linker (/IDE) errors working with filesystem
by Michael Powell 20 Apr '13

20 Apr '13

Hello, I'm a novice (perhaps dangerously intermediate) boost user and have what I think is a linker error folding in filesystem, which would be a great thing to use for, well, file-system-y concerns in our software. However, am running into some strange conflicts between std::string and boost::filesystem. I can either use one or the other, but not both, without (what are possibly) "false positives" in the CodeBench IDE. We are targeting ArchLinux running on ARM cross compiled. As far as I know, I accepted the defaults building boost, excepting for python, etc. Linking against boost statically. I also ran across this article and wonder how I can ensure that we're linking in a correct order: http://www.boost.org/boost-build2/doc/html/bbv2/faq/liborder.html, if that's a plausible culprit / solution. I seem to recall there being auto-link support, but I'm not sure this will work in a toolchain like GCC (4.7.2). I want to say that possibly there is an IDE confusion using boost::filesystem with std::string, but is a tool chain issue not a boost issue. Regards, Michael Powell

1 1

[BGL] directed_graph_adapter
by Andreas Fabri 19 Apr '13

19 Apr '13

Hello, Did anybody write an adapter class (similar to filtered_graph) that gives a directed view on an undirected bidirectional graph. Or an adapter in the other direction, that is an undirected view on a directed graph. If not, is there a major obstacle, that is it simply cannot be implemented, even if it seems straightforward. best regards, andreas -- Andreas Fabri, PhD Chief Officer, GeometryFactory Editor, The CGAL Project phone: +33.492.954.912 skype: andreas.fabri

2 1

boost::cmatch indices
by Rob.Conde＠ai-solutions.com 19 Apr '13

19 Apr '13

Is there a reason why boost::cmatch.size() returns size_type, but boost::cmatch operator[] takes int? Thanks, Rob Conde

2 1

boost::asio::deadline_timer destruction
by Daniel 19 Apr '13

19 Apr '13

Hello, I've noticed that WaitHandler can be called after boost::asio::deadline_timer destruction. It may cause using of uninitialized data. Are there any other solutions of graceful destruction of boost::asio::deadline_timer to be sure that after this destruction WaitHandler will never be called? Example pseudo code: class UsingDeadlineTimer { char some_data_accessed_from_the_wait_handler[512]; boost::asio::deadline_timer timer; void WaitHandler(const boost::system::error_code &ec) { if(ec == boost::asio::error::operation_aborted) { return; } memset(some_data_accessed_from_the_wait_handler, 'E', 512); // cause the problem, because UsingDeadlineTimer may be already destroyed. } UsingDeadlineTimer() : timer(io_service) { timer.expires_at(the moment of UsingDeadlineTimer destruction); timer.async_wait( boost::bind(&UsingDeadlineTimer::WaitHandler, this, boost::asio::placeholders::error) ); } ~UsingDeadlineTimer() { timer.cancel(); // but we already can be in the WaitHandler body which will access some_data_accessed_from_the_wait_handler } }; Thank you, Daniel

2 5

mpl vector of pair access
by Olaf Peter 19 Apr '13

19 Apr '13

Hello, in these code I try to unpack the 1stand 2nd element, but it doesn't compile (here, it complains about »apply« in »struct boost::mpl::at_impl<boost::mpl::non_sequence_tag>« Is there a better way and how to get it to compile? Thanks, Olaf ---8<--- #include <boost/mpl/vector.hpp> #include <boost/mpl/vector_c.hpp> #include <boost/mpl/max_element.hpp> #include <boost/mpl/pair.hpp> #include <boost/mpl/integral_c.hpp> #include <boost/mpl/size_t.hpp> #include <boost/mpl/placeholders.hpp> #include <boost/mpl/at.hpp> #include <iostream> namespace mpl = boost::mpl; struct code { enum type { undefined, foo, bar }; }; typedef mpl::vector<std::size_t, // min max mpl::pair< mpl::size_t<0>, mpl::size_t<0> >, // undefined mpl::pair< mpl::size_t<1>, mpl::size_t<3> >, // foo mpl::pair< mpl::size_t<2>, mpl::size_t<5> > // bar > arity_info; template <code::type code> struct min_arity : mpl::at_c< typename mpl::at_c<arity_info, code>::type, 0 >::type { }; // same for max_arity at index 1 (pair::second) int main() { std::cout << "min arity = " << min_arity<code::bar>::value << '\n'; // std::cout << "max arity = " // << max_arity<code::bar>::value << '\n'; } --->8---

2 7