March 2011 - Boost - lists.preview.boost.org

Deprecation guidelines?
by Daniel Herring 18 Mar '11

18 Mar '11

I was trying to figure out how Boost handles deprecated classes, functions, headers, macros, etc. The following command finds several approaches within boost $ grep -ir deprecate boost-1.44.0/include/boost/* \ | grep -v "This header is deprecated" \ | grep -v BOOST_SPIRIT_DEPRECATED Surprisingly, none of these use compiler support. e.g. http://stackoverflow.com/questions/295120/c-mark-as-deprecated Where can one find guidelines on how to deprecate things in Boost? What is the proper way to check that code using Boost is clean? Thanks, Daniel

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Boost Trunk LKGR
by Joshua Boyce 18 Mar '11

18 Mar '11

Hey all, I was wondering if there was any way to query for the Last Known Good Revision of the Boost trunk? It would be great if there was a file or something on the website that had the revision number of the latest build to compile cleanly and pass all tests, either for all platforms, or one file for each platform. For an example of this in practice elsewhere, see the Chromium project: https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code… <https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code…> Thanks.

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Deprecation of compilers and libraries
by Jeroen Habraken 18 Mar '11

18 Mar '11

Hi, It seems the acceptance of Phoenix V3 has raised the question on how to handle the deprecation of compilers and libraries again. I believe it is important to reach a consensus and to make an official statement regarding it, as it's important for both users and developers. Below I've assembled a set of questions I would like to see answered: Compilers: 1. What minimum of compilers should a library support for it to be considered for review? 2. What is necessary for a compiler previously supported to be removed from this list? Libraries: 3. Should library X be marked as preferred over library Y, since multiple solutions to a similar problem are becoming more common and the right choice might not be obvious to a user? 4. Can an existing library be marked "deprecated"? 5. Once deprecated will a library be removed from boost after X releases? 6. Should a backwards compatible solution exist for a library to be removed? Personally I believe dead branches should, in due time, be cut from the tree for boost to remain at the forefront of C++ development. Especially now the number of libraries is growing, we should aim for clarity. Regards, Jeroen Habraken

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[phoenix] Upcoming release - What about the rest?
by Thomas Heller 18 Mar '11

18 Mar '11

Hi all, The next boost release is nearing and I want to include Phoenix. However, there are some questions that needs to be solved. How to deal with Boost.Bind and Boost.Lambda? First of all, I don't think its a good idea to remove either of those. However, should Phoenix deprecate Boost.Bind and Boost.Lambda? If yes, how should this deprecation be handled? My main concern is that most users will just continue to use BB and BLL just because of their names. What about Phoenix V2? For V2 I have a clearer vision. I would like to have three phases: 1) Have V2 and V3 coexist in the tree, have a macro that decides which version should be included. will default to V2 2) deprecate V2, change the default of the macro introduced in 1) to V3 Alternatives: 3 a) remove phoenix v2 3 b) move phoenix v2 to another namespace so that V3 and V2 don't interfere anymore Best regards, Thomas

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[valid_ptr] proposing a new type of pointer object that allows validity tracking without memory management and object ownership
by Dan Walters 17 Mar '11

17 Mar '11

Dear all, I am posting to propose a new light weight pointer object library (boost.valid_ptr) that provides safe validity checking without having to take ownership or the the responsibility of memory management of the object pointed to. The intention is to develop a useful pointer object that is easy to use and handles validity in a simple and invisible manner, to be used just like a normal pointer and in a way that a programmer would be familiar with, to produce cleaner and more intuitive code than other pointer libraries for its problem domain. The library would be best used when it is difficult to determine when an object will be released, for example, when pointing to objects higher on the stack, objects that are members of other objects or objects contained within a boost.ptr_container. The library is to be practically useful and most useful where boost.smart_ptr and boost.ptr_container libraries are not appropriate (for example, due to memory management or ownership not being required). The valid_ptr library is to be optimized for access rather than fast assignment / de-assignment. Detailed proposal: https://docs.google.com/document/pub?id=1wod4CbeL9x8rLJ2S8815akMAGmYj-fCq90… I am posting here in the hope it will generate suitable interest that it may be worth developing as a full library for submission. Best wishes, Dan

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compile error with boost::archive::text_oarchive
by Eun-Sung Kim 17 Mar '11

17 Mar '11

Hi, all Compile error is occurred in the following program "VerySimpleCase .cpp" on http://www.boost.org/doc/libs/1_46_1/libs/serialization/doc/tutorial.html#s…. The statements in line no. 45 and 56 cause problems. Could you fix it up? Thanks, --Kim ps 1) VerySimpleCase .cpp 1 #include <fstream> 2 3 // include headers that implement a archive in simple text format 4 #include <boost/archive/text_oarchive.hpp> 5 #include <boost/archive/text_iarchive.hpp> 6 7 ///////////////////////////////////////////////////////////// 8 // gps coordinate 9 // 10 // illustrates serialization for a simple type 11 // 12 class gps_position 13 { 14 private: 15 friend class boost::serialization::access; 16 // When the class Archive corresponds to an output archive, the 17 // & operator is defined similar to <<. Likewise, when the class Archive 18 // is a type of input archive the & operator is defined similar to >>. 19 template<class Archive> 20 void serialize(Archive & ar, const unsigned int version) 21 { 22 ar & degrees; 23 ar & minutes; 24 ar & seconds; 25 } 26 int degrees; 27 int minutes; 28 float seconds; 29 public: 30 gps_position(){}; 31 gps_position(int d, int m, float s) : 32 degrees(d), minutes(m), seconds(s) 33 {} 34 }; 35 36 int main() { 37 // create and open a character archive for output 38 std::ofstream ofs("filename"); 39 40 // create class instance 41 const gps_position g(35, 59, 24.567f); 42 43 // save data to archive 44 { 45 boost::archive::text_oarchive oa(ofs); // compile error at here !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 46 // write class instance to archive 47 oa << g; 48 // archive and stream closed when destructors are called 49 } 50 51 // ... some time later restore the class instance to its orginal state 52 gps_position newg; 53 { 54 // create and open an archive for input 55 std::ifstream ifs("filename"); 56 boost::archive::text_iarchive ia(ifs); // compile error at here !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 57 // read class state from archive 58 ia >> newg; 59 // archive and stream closed when destructors are called 60 } 61 return 0; 62 } 63 ps2) compile error message (partly) /tmp/ccnNHOct.o: In function `boost::archive::text_iarchive& boost::smart_cast_impl::reference<boost::archive::text_iarchive&>::polymorphic::cross::cast<boost::archive::detail::basic_iarchive>(boost::archive::detail::basic_iarchive&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost15smart_cast_impl9referenceIRNS_7archive13text_iarchiveEE11polymorphic5cross4castINS2_6detail14basic_iarchiveEEES4_RT_+0x1b): undefined reference to `typeinfo for boost::archive::detail::basic_iarchive' /tmp/ccnNHOct.o: In function `boost::archive::text_oarchive& boost::smart_cast_impl::reference<boost::archive::text_oarchive&>::polymorphic::cross::cast<boost::archive::detail::basic_oarchive>(boost::archive::detail::basic_oarchive&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost15smart_cast_impl9referenceIRNS_7archive13text_oarchiveEE11polymorphic5cross4castINS2_6detail14basic_oarchiveEEES4_RT_+0x1b): undefined reference to `typeinfo for boost::archive::detail::basic_oarchive' /tmp/ccnNHOct.o: In function `void boost::archive::text_oarchive_impl<boost::archive::text_oarchive>::save<int>(int const&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost7archive18text_oarchive_implINS0_13text_oarchiveEE4saveIiEEvRKT_+0x15): undefined reference to `boost::archive::basic_text_oarchive<boost::archive::text_oarchive>::newtoken()' /tmp/ccnNHOct.o: In function `void boost::archive::save_access::save_primitive<boost::archive::text_oarchive, int>(boost::archive::text_oarchive&, int const&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost7archive11save_access14save_primitiveINS0_13text_oarchiveEiEEvRT_RKT0_+0x15): undefined reference to `boost::archive::detail::basic_oarchive::end_preamble()' /tmp/ccnNHOct.o: In function `void boost::archive::text_oarchive_impl<boost::archive::text_oarchive>::save<boost::archive::class_id_reference_type>(boost::archive::class_id_reference_type const&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost7archive18text_oarchive_implINS0_13text_oarchiveEE4saveINS0_23class_id_reference_typeEEEvRKT_+0x15): undefined reference to `boost::archive::basic_text_oarchive<boost::archive::text_oarchive>::newtoken()' /tmp/ccnNHOct.o: In function `void boost::archive::save_access::save_primitive<boost::archive::text_oarchive, boost::archive::class_id_reference_type>(boost::archive::text_oarchive&, boost::archive::class_id_reference_type const&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost7archive11save_access14save_primitiveINS0_13text_oarchiveENS0_23class_id_reference_typeEEEvRT_RKT0_+0x15): undefined reference to `boost::archive::detail::basic_oarchive::end_preamble()' /tmp/ccnNHOct.o: In function `void boost::archive::text_oarchive_impl<boost::archive::text_oarchive>::save<boost::archive::class_id_type>(boost::archive::class_id_type const&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost7archive18text_oarchive_implINS0_13text_oarchiveEE4saveINS0_13class_id_typeEEEvRKT_+0x15): undefined reference to `boost::archive::basic_text_oarchive<boost::archive::text_oarchive>::newtoken()' /tmp/ccnNHOct.o: In function `void boost::archive::save_access::save_primitive<boost::archive::text_oarchive, boost::archive::class_id_type>(boost::archive::text_oarchive&, boost::archive::class_id_type const&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost7archive11save_access14save_primitiveINS0_13text_oarchiveENS0_13class_id_typeEEEvRT_RKT0_+0x15): undefined reference to `boost::archive::detail::basic_oarchive::end_preamble()' /tmp/ccnNHOct.o: In function `void boost::archive::text_oarchive_impl<boost::archive::text_oarchive>::save<float>(float const&)': VerySimpleCase.cpp:(.gnu.linkonce.t._ZN5boost7archive18text_oarchive_implINS0_13text_oarchiveEE4saveIfEEvRKT_+0x15): undefined reference to `boost::archive::basic_text_oarchive<boost::archive::text_oarchive>::newtoken()'

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[1.47] Serialization for std::tr1::unordered
by Jim Bell 17 Mar '11

17 Mar '11

Since we're talking about 1.47, I'd like to draw some attention to TR1 and serialization. I submitted a patch to serialize std::tr1::unordered, the std container not presently covered. <https://svn.boost.org/trac/boost/ticket/5265> Any chance of getting this into 1.47?

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Maintainer of Boost.Bind and Boost.Lambda
by Thomas Heller 17 Mar '11

17 Mar '11

Hi all, Who are the maintainers of Boost.Bind and Boost.Lambda? I couldn't find a list of active maintainers of the different boost libraries. I think such a list would be great in general. Regards, Thomas

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Boost profile for ODB
by Boris Kolpackov 17 Mar '11

17 Mar '11

Hi, I would like to briefly mention that we have released the Boost profile for ODB, an open-source object-relational mapping (ORM) system for C++. The Boost profile provides glue code that seamlessly integrates various Boost components, such as smart pointers, containers, and value types, with ODB. This initial release of the profile covers the most commonly used types from the smart_ptr, unordered, and date_time Boost libraries. For example, now we can easily persist a class like this: #pragma db object class employee { ... boost::gregorian::date born_; boost::unordered_set<std::string> emails_; boost::shared_ptr<employer> employer_; }; For a more detailed discussion of the Boost profile, see the following blog post: http://www.codesynthesis.com/~boris/blog/2011/03/16/odb-1-2-0-released/ Or refer directly to Part III, "Profiles" in the ODB Manual: http://www.codesynthesis.com/products/odb/doc/manual.xhtml#III Boris

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[Review] Boost.Type Traits Extension by Frederic Bron
by Joachim Faulhaber 17 Mar '11

17 Mar '11

... went accidental to Boost-users only 2011/3/17 Joachim Faulhaber <afojgo(a)googlemail.com>: > 2011/3/17 Paul A. Bristow <pbristow(a)hetp.u-net.com>: >> * Some simpler (trivial even) examples might help newcomers to the library? >> The examples given are 'interesting' but quite complicated. > > Are there examples in the docs? > > As far as I can see, there is an example on the implementation only. > No examples on usage. They seem to be missing from the > libs/type_traits/example directory as well. > > Regards, > Joachim > > P.S.: Thanks to Frederic (and assisting operatorists) for this effort > and good teamwork. The library extension looks pretty well to me :) > > -- > Interval Container Library [Boost.Icl] > http://www.joachim-faulhaber.de

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