April 2015 - Boost - lists.boost.org

Boost.locale update
by Maks Naumov 20 Apr '15

20 Apr '15

Any plans to update the Boost.Locale ? In https://github.com/boostorg/locale/pulls there are some fixes.

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[ValueRef] Interest in a new library for immutable values with internal sharing?
by THOMAS JORDAN 20 Apr '15

20 Apr '15

Hi, I'd like to gauge whether there might be any interest in a new Boost library comprising a generic, non-intrusive, wrapper class for creating immutable/const values with sharing of the underlying object via internal reference counting. This new class would be called ValueRef (or possibly just Value), and it would effectively provide an assignable/swappable 'reference'/handle to shared, const values. It can be considered an effective alternative to the commonly used shared-pointer-to-const idiom, providing cleaner and more explicit value semantics, whilst also hiding calls to 'new' as an internal implementation detail. In a nutshell, ValueRef adapts a regular type T to give a new type ValueRef<T> with const T value semantics and uses reference counting of an underlying object on the heap internally to reduce copying overhead. ValueRef will spawn off a new copy of the wrapped object (if necessary) if the ValueRef is assigned another ValueRef or another object of type T. Const functions of T do not incur any overhead of counter access or copy and are invoked by either * or -> syntax. Forwarding constructors are provided which permit the wrapped value to be constructed in place, and conversion operator allows inter-operation with values of the unwrapped type. ValueRef also provides the common relational operators. I have so far implemented a rough (C++03-only so far) version of this (based on a stripped down version of Adobe::copy_on_write library) and a test suite and it seems to work okay. Example usage: /* type of ValueRef wrapped std::vector<int> */ typedef ValueRef<std::vector<int> > ValueRefVecType; /* create vector of 10 elements via forwarding constructor */ ValueRefVecType valueRefVector1(10,1); /* non-mutating/const op */ assert( valueRefVector1->size() == 10 ); /* non-mutating/const op */ assert( (*valueRefVector1)[0] == 1 ); /* error - compilation failure occurs calling a non-const op */ (*valueRefVector)[0] = 2; /* copy ctor */ ValueRefVecType valueRefVector2(valueRefVector1); /* test for equality */ assert( valueRefVector1 == valueRefVector2 ); /* test for equality (implicit conversion) */ assert( valueRefVector2 == std::vector<int>(10,1) ); /* valueRefVector1 and valueRefVector2 share same std::vector */ assert( valueRefVector1.identity(valueRefVector2) ); /* ref count is no longer one */ assert( !valueRefVector1.unique_instance() ); /* new value */ valueRefVector1 = std::vector<int>(5); /* non-mutating/const */ assert( valueRefVector1->size() == 5 ); /* test for equality - value semantics */ assert( !(valueRefVector1 == valueRefVector2) ); /* valueRefVector1 and valueRefVector2 do not share same std::vector */ assert( !valueRefVector1.identity(valueRefVector2) ); I am not aware of anything else current that provides this functionality. Regards, Tom

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[release] Python 3 build problems
by Daniel James 20 Apr '15

20 Apr '15

Hi, Is there anyone who can write a brief description of the build problem with python 3 for the release notes? We probably should say something. thanks, Daniel

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[regex] Support for Perl's (*SKIP)
by Sei Lisa 20 Apr '15

20 Apr '15

I'd like to see support for Perl's (*SKIP) regex verb in Boost. There are a number of verbs, but that one has an interesting and frequent use case: it enables searching for an expression but only outside of some contexts. There is a page called "The best regex trick" with details about the process and a number of examples. I can't link to it as this is my first message (I attempted before but it was rejected). It explains how to do it with and without (*SKIP). I've seen several questions in Stack Overflow asking how to accomplish that task, so it seems it's quite frequent to run into that need. Let's say for example that we want to find the string 'foo' as an identifier in C. This is a crude example of a Perl regex that does it (a real one might need to be more elaborate; in particular, backslashes for line continuation are not considered): (?x-s) (?# free spacing, dot doesn't match newline) (?://.*+ (?# eat single-line comment text) |/\*[\S\s]*?\*/ (?# eat multi-line comment text) |"(?:\\.|[^"\n])*+" (?# eat string text) )(*SKIP)(?!) (?# skip these) |\bfoo\b (?# match this) regex::search will match that expression only when foo is present outside of a string or comment. Without (*SKIP), it can be done only by calling regex::search multiple times, using an expression like this: (?-s)//.*+|/\*[\S\s]*?\*/|"(?:\\.|[^"\n])*+"|(\bfoo\b) and ignoring every match where group 1 wasn't matched. That's presumed to be slower, and certainly more inconvenient for the programmer. Support for this particular use case would be a great feature to have in the regex engine. Sei

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[master] Open for 1.59?
by Joaquin M Lopez Munoz 20 Apr '15

20 Apr '15

Is master already open for commits towards Boost 1.59? Thank you, Joaquín M López Muñoz Telefónica

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[config] BOOST_SYMBOL_VISIBLE on MinGW
by Robert Ramey 20 Apr '15

20 Apr '15

I made adjustments so that the serialization library on Develop branch will build with default visibilty = hidden. There is a little more to this than one would think. Basically I used BOOST_SYMBOL_VISIBLE on all "exported" classes (and their base classes) and BOOST_ARCHIVE_DECL ( defined as either BOOST_ARCHIVE_IMPORT or BOOST_ARCHIVE_EXPORT) on exported/visible member functions. This seems to give me what I need in that things build and test for gcc, clang, MSVC. EXCEPT for gcc under MinGW. see http://www.boost.org/development/tests/develop/developer/output/MinGW-32%20… The message seems to indicate to me that I should have BOOST_SYMBOL_VISIBLE on the class declaration - which seemed to resolve similar compilation errors with GCC on other platforms. Poking around config/compiler/gcc.hpp and config/plaform/w32.hpp It seems to me that this scheme things look OK - that is it looks that BOOST_SYMBOL_VISIBILITY should be defined as __attribute__((__visibility__("default"))) I'm also puzzled by the fact that the linker craps out only on this on declaration. Any help appreciated. Robert Ramey -- View this message in context: http://boost.2283326.n4.nabble.com/config-BOOST-SYMBOL-VISIBLE-on-MinGW-tp4… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[container][stable_vector] What does reserve() do for stable_vector
by Arindam Mukherjee 19 Apr '15

19 Apr '15

Consider the following code. #include <string> #include <boost/container/stable_vector.hpp> #include <iostream> int main() { boost::container::stable_vector<std::string> vec; vec.reserve(10); std::cout << "capacity = " << vec.capacity() << '\n'; } On running this (on g++ and Linux), the output is: capacity = 4294967286 (that's 2^32 - 10) If replace boost::container::stable_vector with std::vector above, the output is: capacity = 10 I know it could as well have been capacity = 20, or capacity = 64 or whatever but that's still sane behavior. What capacity() returns for stable_vector seems to be (2^32 - N), N being the requested capacity. I didn't see such a definition of capacity in the docs: http://www.boost.org/doc/libs/1_56_0/doc/html/boost/container/stable_vector… Thanks, Arindam

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[type_traits] Testing for copy constructor
by Edward Diener 19 Apr '15

19 Apr '15

Does one use has_trivial_copy or has_nothrow_copy to determine if a class has a copy constructor or not ? I am writing some code that can do different things depending on whether a particular class has a copy constructor or does not have a copy constructor. I do not really care whether the copy constructor is a compiler generated copy constructor or not.

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Feedback on Boost.Http
by Vinícius dos Santos Oliveira 18 Apr '15

18 Apr '15

I recently submitted an HTTP server library to Boost Incubator and I'd appreciate feedback: http://rrsd.com/blincubator.com/bi_library/http/?gform_post_id=1460 I intend to submit to Boost later. This is the library that I developed during GSoC 2014 and I made several improvements (new features, bug fixes, better and extended documentation...) after the end of GSoC. There are a few improvements that I still want to do, but none of them would be a barrier for Boost integration, in my opinion. This library doesn't have a builtin request router, opposed to several libraries out there, then you can use whatever routing style you wish (tree-based, middleware-based, no router...). Also, it follows Boost active style, then you can build your own scheduler around it (prioritize requests from certain IPs, defer acceptance of new connections during server high load, reuse prior constructed objects...). The library follows Asio threading model, then you also choose whether you will handle all requests from the same thread (useful for embedded devices) or multiples ones. The library is fully async, then one thread is not a problem. It has a powerful and flexible file server API, supporting range-based requests, conditional requests, support for ETags and so on. After the GSoC, I had the chance to add tests for asynchronous abstractions and now the implementation is much more trustable and stable. The choice to reuse an existing HTTP parser (the Node.js's C parser) also helps a lot. The simple message-based API helps to support HTTP pipelining, allocation fine tuning and much more. Besides HTTP pipelining, HTTP chunking (and other modern features like 100-continue and HTTP Upgrade) are also supported. There are zero reviews/comments on Boost Incubator right now and I'd love to see more eyes on this lib that does better on many fronts than previous choices. Benchmark is one item that I still need to tackle, btw. But I hope to see good results here too. -- Vinícius dos Santos Oliveira https://about.me/vinipsmaker

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[tools] How to use 1.58.0/bjam --toolset=sun for specified stdlib feature?
by Sergey Sprogis 18 Apr '15

18 Apr '15

Running boost regression unit tests I found it convenient to direct output from every single tested library into a separate logfile. To do that, my testing script (bash) at first extracts the list of all <library>/test lines from status/Jamfile.v2, and puts them into another test_suites.txt file. Then it runs all extracted test suites like this: my_res_dir= `pwd` for dir in `cat test_suites.txt`; do dir1=`echo $dir | sed "s/\//\./g"` cd $BOOST_ROOT/libs/$dir bjam --toolset=sun variant=release > $my_res_dir/$dir1.log 2>&1 done All that worked fine until boost-1.58 in which tools/build/src/tools/sun.jam file was modified so that instead of single standard library it now allows the possibility of using any of 5 available libraries. The question is, how exactly should I define bjam's options in my bash script shown above, if for example, I want to use gnu library in c++03 mode? The proper code inside sun.jam file looks like this: feature.extend stdlib : gnu ; feature.compose <stdlib>gnu : <cxxflags>-std=c++03 <linkflags>-std=c++03 ; but how should I tell to bjam to use this specific library? Thanks, Sergey

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[build] [boost 1.58] Error when compiling with MSVC-7.1
by Ion Gaztañaga 18 Apr '15

18 Apr '15

Hi, I just tried the newly released version with this toolset (I don't think many will use and support it, but still useful). Output when building move from boost/libs/move/test: ..\..\..\b2.exe toolset=msvc-7.1 variant=debug C:/Data/Libs/boost/tools/build/src/tools\msvc.jam:1075: in configure-really *** argument error * rule generate-setup-cmd ( version : command : parent : options * : cpu : global-setup : default-global-setup-options : default-setup ) * called with: ( 7.1 : C:\Program Files (x86)\Microsoft Visual Studio .NET 2003\Vc7\bin : C:\Program Files (x86)\Microsoft Visual Studio .NET 2003\Vc7 : <command>C:\Program Files (x86)\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.exe : i386 : : x86 : vcvars32.bat ) * missing argument global-setup C:/Data/Libs/boost/tools/build/src/tools\msvc.jam:809:see definition of rule 'generate-setup-cmd' being called C:/Data/Libs/boost/tools/build/src/tools\msvc.jam:201: in configure C:/Data/Libs/boost/tools/build/src/tools\msvc.jam:153: in msvc.init C:/Data/Libs/boost/tools/build/src/build\toolset.jam:43: in toolset.using C:/Data/Libs/boost/tools/build/src\build-system.jam:461: in process-explicit-toolset-requests C:/Data/Libs/boost/tools/build/src\build-system.jam:527: in load C:\Data\Libs\boost\tools\build\src/kernel\modules.jam:289: in import C:\Data\Libs\boost\tools\build\src/kernel/bootstrap.jam:139: in boost-build C:\Data\Libs\boost\boost-build.jam:17: in module scope I've found a workaround adding this to user-config.jam, in case anyone needs a workaround: using msvc : 7.1 : : <setup>"C:/Program Files (x86)/Microsoft Visual Studio .NET 2003/Vc7/bin/vcvars32.bat" ; Of course that path is in a 64-bit Windows OS, adjust it to your installed path. Best, Ion

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[Hana] Formal review dates
by Louis Dionne 17 Apr '15

17 Apr '15

Dear Boost, As I already announced in a previous message, a formal review is about to be asked for Hana. The current preferred dates would be April 25 - May 8. However, we are concerned that people might be unavailable to do reviews such a short time before C++Now. The goal of this message is to ask potential reviewers whether they would be available during the proposed period. If people seem unfavorable or if there is too little feedback to this message, we will consider pushing back the review to after C++Now. Note that one reason why I'm trying to squeeze the review before C++Now is because it could hugely help with marketing the library if it was accepted. Regards, Louis

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Release Status?
by Olaf van der Spek 17 Apr '15

17 Apr '15

Hi, What's the status of the release? -- Olaf

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Re: [boost] [Boost-users] [IPC Named Mutex]
by Tom Kent 16 Apr '15

16 Apr '15

On Thu, Apr 16, 2015 at 3:01 AM, Lorenzo Trivelli < trivelli.lorenzo(a)konvergence.it> wrote: > Hi to everyone, > I'm experiencing a strange behaviour of named mutex on > a windows 2008 machine. > symptoms: when the system event log is empty, creation > of named mutex fails with a boost::interprocess::interprocess:exception > with msg boost::interprocess_exception::library_error. > Now some data: > 1) Boost 1.57.0 + stlport 5.2 > 2) VS 2005 > 3) Target Environment: Win 2008/32 > 3) after a night of code digging I managed to crete a small sample > which raises the exception: > > #include <boost/shared_ptr.hpp> > #include <boost/interprocess/sync/named_mutex.hpp> > #include <boost/interprocess/sync/scoped_lock.hpp> > #include <iostream> > > typedef boost::shared_ptr<boost::interprocess::named_mutex> > safe_ipc_mx; > > static safe_ipc_mx __mx; > int main(void) { > system("pause"); > try { > __mx = safe_ipc_mx(new > boost::interprocess::named_mutex(boost::interprocess::open_or_create_t(),"JAEGER")); > std::cout << std::endl << "Mutex created !" << std::endl; > } catch(boost::interprocess::interprocess_exception const& e) { > std::cout << std::endl << "Mutex creation error " << > e.what() << " /" << e.get_error_code() << " /" << e.get_native_error(); > } > system("pause"); > return 0; > > } > > I tried it also, and got the same result. I also tried with msvc-12.0, same result. > as far as I digged, it seems that the trouble is in the > winapi::get_last_bootup_time(stamp) call > in shared_dir_helpers.hpp, but up to now I had not been able to reproduce > it on a machine with > all the debugging tools installed > get_last_bootup_time() looks through the system event log for event ID == 6005 (event log started)...since the event log was cleared out, this is not found. I guess that is a bug in boost. One thing you could try...in interprocess's win32_api.hpp, there is another implementation of get_last_bootup_time() which uses WMI instead of the event log (there were warnings in the source about WMI not supporting hibernation/clock changes correctly, so beware). If you define BOOST_INTERPROCESS_BOOTSTAMP_IS_LASTBOOTUPTIME it should use that other version...give that a try. (in visual studio Project Properties -> C/C++ -> Preprocessor -> Preprocessor Definitions: add a semi colon ';' then the above item) That worked for me on windows 7. I submitted a pull request to automatically fallback to WMI if the event log started event isn't in the log. https://github.com/boostorg/interprocess/pull/18 Tom

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[serialization] failing MPI build
by Alain Miniussi 16 Apr '15

16 Apr '15

Hi, Am I the only one with a (global) failing build on MPI ? ../../../boost/archive/detail/interface_oarchive.hpp(63): error: no instance of overloaded function "boost::mpi::detail::content_oarchive::save_override" matches the argument list argument types are: (const boost::archive::tracking_type) object type is: boost::mpi::detail::content_oarchive this->This()->save_override(t); I am going to investigate, but maybe I missed something obvious. Thanks Alain

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std::map<> - like structure for other than std::pair<>?
by David Hagood 16 Apr '15

16 Apr '15

Several times I have run into a use case where I have some object that I would like to access via something like a std::map<>, but which already contains a member that I would like to use as a key. Is there any data structure that "acts like a map", but instead of storing std::pair<key,value> allows me to store an object directly, and specify what member of that object is the key value? I can give a specific use case for this: For those of you not familiar with the SCA, there is an object called CF::Properties. This is a CORBA sequence (think std::vector) of objects of {string name, CORBA::Any value}, used to store metadata. Ideally, I'd like to have an object that I could initialize from that sequence that would allow me to do things like this: inline string &getKey(CF::Property &x) { return x.name; } void foo(CF::Properties &meta) { mapLikeThing<CF::Property,getKey> myMap(meta); double sampleRate; myMap["SampleRate"] >> sampleRate; setHardwareSampleRate(sampleRate); }

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Fwd: Windows Intel Compiler problem
by Mari Pecha 15 Apr '15

15 Apr '15

Good morning, I try compile boost with Intel Compiler under Windows OS, but I got an error message screen is in attachments. I don't know what I'm doing wrong, can you help me? Thank you Mari --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com

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GSOC 2015 Sample Code
by Aditya Avinash Atluri 14 Apr '15

14 Apr '15

Hi, I was unable to put sample code during submission because I was busy with Mesa. Here is the sample code: https://gist.github.com/adityaatluri/22c97a726c304d9e5c50 -- Regards, Aditya Avinash Atluri, Graduate Student, Electrical and Computer Engineering, The George Washington University, Washington, DC.

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htmlspecialchars and urlencode?
by Olaf van der Spek 14 Apr '15

14 Apr '15

Hi, Does Boost have functions like htmlspecialchars and urlencode (from PHP)? If not, I think they'd make a nice addition to the string algorithm lib. -- Olaf

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boost::posix_time::duration_from_string throws std::out_of_range
by George Georgiev 13 Apr '15

13 Apr '15

Hi, I just noticed that boost::posix_time::duration_from_string throws std::out_of_range when I pass empty string to it. This seems like a bug, IMHO it should throw boost::bad_lexical_cast as it does for any other problem with the input. Thanks, George

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Git tags and Boost release
by Robert Ramey 12 Apr '15

12 Apr '15

I look in my history of the master branch and It seems to me I would like to be able to know which commit corresponds to which Boost release. I think the correct functionality to do this is described here. http://git-scm.com/book/en/v2/Git-Basics-Tagging I'm wondering if we want to do this upon release so we can remember where we were when something blows up. Ideally, I'd like the release managers to be able to just global to the "mark" when the release is "official" I like git - but anything I haven't done before is out of my comfort zone. So any insight would be appreciated. Robert Ramey -- View this message in context: http://boost.2283326.n4.nabble.com/Git-tags-and-Boost-release-tp4674328.html Sent from the Boost - Dev mailing list archive at Nabble.com.

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[modular boost][install] Signals2 include links not being generated during build
by Greg Rubino 12 Apr '15

12 Apr '15

Hi, I'm building modular boost on 32-bit debian linux, and the build runs without error, but the links for some of the header files are not created. Here's what I'm running: $ bash bootstrap.sh $ ./b2 --runtime-link=static --without-python --without-mpi --without-iostreams At the end of the build (which shows warnings but no failures), I get this message: """ ...updated 836 targets... The Boost C++ Libraries were successfully built! The following directory should be added to compiler include paths: .../boost The following directory should be added to linker library paths: .../boost/stage/lib """ But for some reason signals2 is not being built. From the boost build directory: $ ls stage/lib/libboost_signals2* ls: cannot access stage/lib/libboost_signals2*: No such file or directory $ ls boost/signals2.hpp ls: cannot access boost/signals2.hpp: No such file or directory I'm not sure what happened or even how to diagnose whatever the issue might be. Has anyone seen this before or have any troubleshooting tips for me? Thanks, Greg

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1.58.0 rc3 is now available
by Marshall Clow 12 Apr '15

12 Apr '15

Release candidate files for 1.58.0 are available at: http://boost.cowic.de/rc/ * Since rc1, the changes that were causing the serialization libraries to fail to build on MSVC have been reverted. * Since rc2, the documentation for bind, and mem_fun. No code changes. As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (boost_1_58_0_rc3.7z) = f7255aeb692c1c38fe761c32fb0d3ecd MD5 (boost_1_58_0_rc3.tar.bz2) = b8839650e61e9c1c0a89f371dd475546 MD5 (boost_1_58_0_rc3.tar.gz) = 5a5d5614d9a07672e1ab2a250b5defc5 MD5 (boost_1_58_0_rc3.zip) = b0605a9323f1e960f7434dbbd95a7a5c Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_58_0.html

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[serialization][develop] Unable to find file or target named 'test_polymorphic_helper.cpp'
by Dmitry Moskalchuk 11 Apr '15

11 Apr '15

It seems that latest commit to develop branch of Boost.Serialization (https://github.com/boostorg/serialization/commit/a32549c25fa983fea2b5dfeaf9…) break build of Boost: error: at /home/cislave/.crystax/ci-boost/regression/android-19-armeabi-v7a-develop/test/develop/regression/armeabi-v7a/test/boost_bb/src/kernel/modules.jam:107 error: Unable to find file or target named error: 'test_polymorphic_helper.cpp' error: referred to from project at error: '../libs/serialization/test' And really, there is no file libs/serialization/test/test_polymorphic_helper.cpp. I guess it was forgotten to be added to git. -- Dmitry Moskalchuk

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[Boost Document Library] Which SDK / OS to use for development?
by Abhinav Tripathi 11 Apr '15

11 Apr '15

I am trying to start the development of a Document Library for Boost which was listed under the GSoC projects list. I successfully built Boost 1.57 on windows 8 with MinGW using some help from this mailing list. Now, i wish to develop the library on windows only (Although i can shift to linux if need be).... When i went through the links provided on the ideas list, i came across following things : --The OpenOffice SDK asks to either use linux or Visual Studio on Windows and there is practically nothing (documentation) for compiling with MinGW. --The LibreOffice SDK also asks to install many *nix tools first and also doesn't mention anything about compatibility with MinGW. --The last 2 links use .NET and some other MS libraries which i am pretty sure won't be much portable... . I wish to develop the library so as to get it accepted to Boost at some point. I assume that Boost would accept only cross platform code, so i discarded the last two links. I am now in a dilemma..... Which of the 2 SDK should i try to use on Windows with MinGW.. Or should i NOT develop on windows and shift to linux... . Also, The MS Office formats are not open but other office formats might be open and hence i can also try and develop something without using any of the available SDKs. So, instead of developing of a wrapper, i can aim to develop a complete library to load and manipulate document files... . Please suggest some option and show me a way as to which SDK/Platform should i use. And how to continue the development for the Document Library. . Regards, Abhinav

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