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Boost.System support for Linux 2.4 kernel?
by J. van der Wulp 10 Nov '08

10 Nov '08

Hello Everyone, Is it possible to add compatibility for the Linux 2.4 kernel to the system library? The file boost/system/linux_error.hpp refers to a few macros/constants that are not defined for the linux 2.4 kernel. The exact names of the symbols are: EKEYEXPIRED, EKEYREJECTED, EKEYREVOKED ENOKEY. Is Linux 2.4 a supported platform for Boost? Thanks, Jeroen

3 2

Library names in system layout on linux
by Vladimir Prus 10 Nov '08

10 Nov '08

Hi, we had discussion about the library names that are produced on Linux, with --layout system: http://thread.gmane.org/gmane.comp.lib.boost.build/19529 Two person who package Boost for different Linuxes participated, and I think we've agreed on some changes that will make them, and hopefully linux users, a bit happier. Now, with --layout=system, the libraries are named like this: libboost_filesystem_mt.so The proposal is to: 1. Drop 'mt', since most libraries are built with MT on Linux, and don't use such special decorations. 2. Add version number at end, to comply with standard packaging. So, we'd create: libboost_filesystem.so.1.38.0 together with a symlink to it, named libboost_filesystem.so I suspect some folks packaging Boost might not be reading Boost.Build list, so I wanted to mention this plan here. Anybody has objections? - Volodya

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[serialization] rvalues and const-correctness?
by David Abrahams 10 Nov '08

10 Nov '08

Consider: struct X { int f(); template <class Archive> void save(Archive& ar, unsigned) { ar << f(); // can't bind non-const reference to temporary } BOOST_SERIALIZATION_SPLIT_MEMBER() }; This error seems silly to me. Couldn't we add this overload to the archives, or even simply replace the existing operator with this one? template<class T> Archive & operator<<(T const & t){ // ^^^^^------------- Note this->This()->save_override(t, 0); return * this->This(); } TIA, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

3 11

Download links on Boost homepage
by Phil Endecott 10 Nov '08

10 Nov '08

Dear All, It seems to take more clicks than necessary to get from the Boost home page to the 1.37.0 download. On the Boost home page there is a heading "News" and under it a link "Version 1.37.0" to http://www.boost.org/users/news/version_1_37_0. To the right of this there's a heading "Downloads" and under it a link "Version 1.37.0" to http://www.boost.org/users/download/version_1_37_0. However, as far as I can see the latter page is identical to the former page; both are news pages listing new and updated libraries etc. The latter page should really have got me closer to being able to download the release, shouldn't it? Phil.

3 2

[thread] shouldn't at_thread_exit work on the main thread?
by vicente.botet 10 Nov '08

10 Nov '08

Hi, in the following example mycallable1 is not called at exit of the main thread. Shouldn't at_thread_exit work on the main thread? What is wrong? Best, Vicente #include <boost/thread.hpp> #include <iostream> struct mycallable1 { void operator()() const { std::cout << "mycallable1" << std::endl; }; }; struct mycallable2 { void operator()() const { std::cout << "mycallable2" << std::endl; }; }; void my_thread() { std::cout << "my_thread" << std::endl; mycallable1 x; boost::this_thread::at_thread_exit(x); } int main() { mycallable2 x; boost::this_thread::at_thread_exit(x); boost::thread th(my_thread); th.join(); return 0; } Output: my_thread mycallable1 EXIT STATUS: 0

1 0

Interest in an Active Object CRTP "decorator"?
by Dean Michael Berris 10 Nov '08

10 Nov '08

Hi Guys, I've recently been working a lot with Active Object implementations. Basically it's an instance of a class that has asynchronous operations scheduled to be executed in its own thread of execution. I'm posting (in-line) a very simple implementation of a CRTP "active object enabler". Any interest in something like this to be included in Boost? --->8-- [NOTE: untested, licensed under the Boost Software License, Copyright 2008 Dean Michael Berris] template <class Derived> struct active { private: shared_ptr<io_service> queue; shared_ptr<io_service::work> sentinel; shared_ptr<thread> lifetime_thread; protected: active() : queue(new io_service()), sentinel(new io_service::work(*queue)), lifetime_thread(new thread(bind(&io_service::run, queue))) { static_cast<Derived*>->init(); }; ~active() { sentinel.reset(); lifetime_thread->join(); static_cast<Derived*>->destroy(); }; void post(function<void()> f) { queue->post(f); }; }; --->8-- Example usage would be something like this: --->8-- struct logger : active<logger> { void init() { }; // required void destroy() { }; // required void operator() (string const & message) { active<logger>::post(bind(&logger::write, this, string(message))); } void write(string message) { cout << message << endl; } }; // ... vector<string> messages; logger log_; for_each(messages.begin(), messages.end(), ref(log_)); --->8-- Hope this helps! -- Dean Michael C. Berris Software Engineer, Friendster, Inc.

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[cryptography] concept
by Kasra Nassiri(Math & ComSci) 10 Nov '08

10 Nov '08

Hi all, I mentioned not a while ago that I am planning to write a boost cryptographic library. I am getting there. We have template classes that implement a certain interface (not virtual functions). These classes are: secure_allocator: An allocator which removes the buffers allocated when they are destructed by overwriting them. block_cipher: Any class that could set a key and encrypt/decrypt a constant size of message. (I have included AES, Serpent, Twofish and MARS, however, we could always add more algorithms) stream_cipher: By definition stream_cipher is a cipher that could process messages of any length. hash_function: Is a class that could compute a cryptographically secure hash signature for an arbitrarily long messages. (I have added whirlpool and will be adding more). wipe_algorithm: An algorithm that provides the patterns of wipe for a given pass and fills a given buffer with patterns (It needs to have a prng template to be used on random patterns). By using a mode of operation we could turn the concept of block_cipher into a stream_cipher. For example cryptolib::ctr<cryptolib::aes> is a stream_cipher concept. I have implemented ictr, ctr and will be implementing XTS, LRW soon. classes: cryptolib::entropy_poll<cryptolib::hash_function>: A class that polls random data and mixes the data using a hash function. cryptolib::entropy_thread<cryptolib::entropy_poll>: Calling the polling function of the entropy_poll at "random" but regulated intervals using boost::thread library. cryptolib::crypto_istream<cryptolib::stream_cipher>: cryptolib::crypto_ostream<cryptolib::stream_cipher>: cryptolib::crypto_oistream<cryptolib::stream_cipher>: classes that behave similar to 'std' iostream ,however, they seamlessly encrypt/decrypt the data as they operate. cryptolib::wipe_fstream<cryptolib::wipe_algorithm>: Wipes the file using the patterns by the template wipe algorithm. This class would determine the cluster size and wipe the entire cluster occupied by the file (this is platform specific, so we need to implement the algorithm for different platforms). finally we have the cryptolib::crypto_fstream that could be given a direction (i.e. encryption or decryption) and will operate seamlessly on the data. What do you think? Anything that I am missing on? Best regards Kasra __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: [boost] [serialization] basic_text_iprimitive destructor throws
by John Salmon 10 Nov '08

10 Nov '08

Here's a two-line patch (not counting the comment). This patch simply ignores any ios_base::failure excpetions from is.sync(). There are certainly other possibilities, but I don't see any good reason to prefer, e.g., checking the result of std::uncaught_exception() first or to broaden the class of caught exceptions. John P.S. I've changed the subject to adhere to conventions. salmonj(a)drdblogin6.en.desres$ diff -u boost/archive/impl/basic_text_iprimitive.ipp.orig boost/archive/impl/basic_text_iprimitive.ipp --- boost/archive/impl/basic_text_iprimitive.ipp.orig 2008-11-09 16:32:30.003405292 -0500 +++ boost/archive/impl/basic_text_iprimitive.ipp 2008-11-09 16:38:51.755281718 -0500 @@ -147,7 +147,17 @@ template<class IStream> BOOST_ARCHIVE_OR_WARCHIVE_DECL(BOOST_PP_EMPTY()) basic_text_iprimitive<IStream>::~basic_text_iprimitive(){ - is.sync(); + try{ + is.sync(); + }catch(std::ios_base::failure& e){ + // is.sync might throw ios_base::failure if an error + // occurs and 'is' has the badbit exception + // mask set. Should this exception be allowed to "leak out" + // of this destructor: + // a) never? + // b) only if std::uncaught_exception() is false? + // c) under some other set of circumstances? + } } } // namespace archive salmonj(a)drdblogin6.en.desres$ On Tue, Nov 4, 2008 at 4:17 PM, John Salmon <john(a)thesalmons.org> wrote: > I tried turning on exceptions on the input stream that I use for a > text_iarchive, hoping to catch user-level errors such as an attempt to > treat a non-archive file as an archive. It seems that when exceptions > are enabled on the underlying stream, the basic_text_iprimitive > destructor throws a second(?) basic_ios::failure exception, during > stack unwinding, which lands me unhappily in the terminate handler. > > Can the basic_text_iprimitive destructor be protected against > accidentally throwing? > > Here's an demonstration. This is on a Linux system with gcc/4.1.2. > > John Salmon > > salmonj(a)drdblogin6.en.desres$ cat ser.cpp > #include <boost/archive/text_iarchive.hpp> > #include <boost/serialization/serialization.hpp> > #include <stdexcept> > > #include <fstream> > > struct Foo{ > int i, j; > private: > friend class boost::serialization::access; > template <class Archive> > void serialize(Archive & ar, const unsigned int version) > { > ar & i & j; > } > }; > > int main(){ > Foo foo; > std::ifstream ifs("/dev/null"); > ifs.exceptions(std::istream::failbit | std::istream::badbit); > > try{ > boost::archive::text_iarchive tia(ifs); > tia >> foo; > }catch(std::ios_base::failure &e){ > std::cerr << "Caught std::ios_base::failure. What: " << > e.what() << "\n"; > }catch(std::exception &e){ > std::cerr << "Caught exception. What: " << e.what() << "\n"; > } > > return 0; > } > > salmonj(a)drdblogin6.en.desres$ xmk > g++ -I/proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/include > -g -L/proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib > -Wl,-rpath,/proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib > ser.cpp -lboost_serialization -o ser > salmonj(a)drdblogin6.en.desres$ ser > terminate called after throwing an instance of 'std::ios_base::failure' > what(): basic_ios::clear > Aborted (core dumped) > salmonj(a)drdblogin6.en.desres$ gdb -c > drdblogin6.en.desres.deshaw.com-6718.core ser > GNU gdb 6.8 > Copyright (C) 2008 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "x86_64-unknown-linux-gnu"... > Reading symbols from > /proj/desrad-c/root/Linux/x86_64/boost/1_37_0-13/Release/lib/libboost_serialization.so...done. > Loaded symbols for > /proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib/libboost_serialization.so > Reading symbols from > /proj/desrad-c/root/Linux/x86_64/gcc/4.1.2-10/lib64/libstdc++.so.6...done. > Loaded symbols for > /proj/desres/root/Linux/x86_64/gcc/4.1.2-10/lib64/libstdc++.so.6 > Reading symbols from /lib64/tls/libm.so.6...done. > Loaded symbols for /lib64/tls/libm.so.6 > Reading symbols from > /proj/desrad-c/root/Linux/x86_64/gcc/4.1.2-10/lib64/libgcc_s.so.1...done. > Loaded symbols for > /proj/desres/root/Linux/x86_64/gcc/4.1.2-10/lib64/libgcc_s.so.1 > Reading symbols from /lib64/tls/libc.so.6...done. > Loaded symbols for /lib64/tls/libc.so.6 > Reading symbols from /lib64/ld-linux-x86-64.so.2...done. > Loaded symbols for /lib64/ld-linux-x86-64.so.2 > Core was generated by `ser'. > Program terminated with signal 6, Aborted. > [New process 6718] > #0 0x0000003f72a2e25d in raise () from /lib64/tls/libc.so.6 > (gdb) where > #0 0x0000003f72a2e25d in raise () from /lib64/tls/libc.so.6 > #1 0x0000003f72a2fa5e in abort () from /lib64/tls/libc.so.6 > #2 0x00002b5ab82f5f84 in __gnu_cxx::__verbose_terminate_handler () > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/libstdc++-v3/libsupc++/vterminate.cc:97 > #3 0x00002b5ab82f4106 in __cxxabiv1::__terminate (handler=0x1a3e) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/libstdc++-v3/libsupc++/eh_terminate.cc:43 > #4 0x00002b5ab82f350b in __cxa_call_terminate (ue_header=0x50b730) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/libstdc++-v3/libsupc++/eh_call.cc:60 > #5 0x00002b5ab82f3fa7 in __gxx_personality_v0 ( > version=<value optimized out>, actions=6, > exception_class=<value optimized out>, ue_header=0x50b730, > context=0x7ffff29e5610) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/libstdc++-v3/libsupc++/eh_personality.cc:637 > #6 0x00002b5ab846a068 in _Unwind_RaiseException_Phase2 (exc=0x50b730, > context=0x7ffff29e5610) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/gcc/unwind.inc:66 > #7 0x00002b5ab846a2db in _Unwind_Resume (exc=0x50b730) > at /state/partition1/tmp/tmpXcQw4O/gcc-4.1.2-10/gcc-4.1.2/gcc/unwind.inc:234 > #8 0x00002b5ab80fd790 in > boost::archive::basic_text_iprimitive<std::istream>::~basic_text_iprimitive > () > from /proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib/libboost_serialization.so > #9 0x00002b5ab8109e0c in > boost::archive::text_iarchive_impl<boost::archive::text_iarchive>::text_iarchive_impl > () > from /proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/lib/libboost_serialization.so > #10 0x00000000004045ab in text_iarchive (this=0x7ffff29e5ae0, > is=@0x7ffff29e58d0, flags=0) > at /proj/desres/root/Linux/x86_64/boost/1_37_0-13/Release/include/boost/archive/text_iarchive.hpp:110 > #11 0x0000000000402c84 in main () at ser.cpp:24 > (gdb) quit > salmonj(a)drdblogin6.en.desres$ >

2 1

[serialization] "Wrapper Type?"
by David Abrahams 09 Nov '08

09 Nov '08

Hi, The documentation uses this term AFAICT without definition anywhere. How am I supposed to know that what I've defined is a "wrapper type" and is_wrapper should be specialized? TIA, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

2 4

[thread] no documented thread move support functions on reference documentation
by vicente.botet 08 Nov '08

08 Nov '08

Hi, the following move support functions are not docummented on the reference documentation. #ifdef BOOST_HAS_RVALUE_REFS template <class F> thread(F&& f); thread(thread&& other); thread& operator=(thread&& other); thread&& move(); #else #ifdef BOOST_NO_SFINAE #else template <class F> explicit thread(F f,typename disable_if<boost::is_convertible<F&,detail::thread_move_t<F> >, dummy* >::type=0) #endif template <class F> explicit thread(detail::thread_move_t<F> f); thread(detail::thread_move_t<thread> x); thread& operator=(detail::thread_move_t<thread> x); operator detail::thread_move_t<thread>(); detail::thread_move_t<thread> move(); #endif Even if the semantics of these functions could be induced for completud it will be good to add them to the reference documentation. The ticket is Ticket #2486 Thanks, Vicente

1 0

[flyweight] post-review version available
by JOAQUIN M. LOPEZ MUÑOZ 08 Nov '08

08 Nov '08

Hello, I'm happy to announce the availability of the post-review version of Boost.Flyweight: *Online docs:* http://tinyurl.com/2sstyr http://svn.boost.org/svn/boost/sandbox/flyweight/libs/flyweight/index.html *Download as .zip:* http://tinyurl.com/hrdm6 http://www.boost-consulting.com/vault/index.php?&direction=0&order=&directo… *Check out from SVN:* https://svn.boost.org/svn/boost/sandbox/flyweight *Tested with:* MSVC++ 8.0 and GCC 3.4.4. Compilation reports most welcome. Older compilers like MSVC++ 6.5 are no longer supported. *What's new:* I've tried to address most of the suggestions and comments raised during the review. The two most important changes are: 1. Alberto Barbati's insightful review has led to the introduction of so-called key-value flyweights (http://tinyurl.com/5mnwjp ). This type of flyweights is meant for the situations where constructing the underlying type is expensive and must be avoided except if absolutely necessary. I think the design is robust enough and covers the variants (inner/outer key) that arose during the discussion with Alberto. 2. A comprehensive performance section is provided (http://tinyurl.com/5ap5kt ). *What's pending* 1. Some of the suggestions given at the review, like reducing intermodule_holder to static_holder when permissible (Vicente Botet) or studying read/write locking policies are still pending or have been postponed to later releases of the library. I felt the current state is sufficiently robust for publication. 2. Serialization support is currently broken, pending the resolution of a proposed feature to add to Boost.Serialization (run-time archive helpers). I'd be very grateful if you can take a look at the post- review version of Boost.Flyweight (specially if you were a reviewer), test it and comment on it, with emphasis on the new features like key-value flyweights. If people are happy with this revision my target release for inclusion will be Boost 1.38. Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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[serialization] Query archive consumed?
by David Abrahams 07 Nov '08

07 Nov '08

Hi, I'd like to verify that there's no data left in a particular archive once I've deserialized my stuff out of it. Is there an appropriate check I can use? Thanks, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

2 1

[threadpool] v15 - final version (?)
by Oliver Kowalke 07 Nov '08

07 Nov '08

Hello, version 15 of threadpool is out - I hope it is the final version. The code doesn't use fibers - fork/join is implemented via recursive execution of tasks (in task::get()). Only tasks in the local worker-queue will be recursivly executed. The work-thread will block in task::get() if the local worker-queue is empty (happens if at least one other worker-thread has stolen a task from the local queue). regards, Oliver -- GMX Download-Spiele: Preizsturz! Alle Puzzle-Spiele Deluxe über 60% billiger. http://games.entertainment.gmx.net/de/entertainment/games/download/puzzle/i…

1 0

Why doesn't boost::exception derive from std::exception?
by Michael Marcin 07 Nov '08

07 Nov '08

Why doesn't boost::exception derive from std::exception? -- Michael Marcin

2 1

[1.37.0] boost test crashes under cygwin gcc-4.x
by Mat Marcus 06 Nov '08

06 Nov '08

When I run a simple test application with a single (empty) BOOST_AUTO_TEST_CASE, boost test causes a crash under cygwin using gcc-4.x. It also crashes for non-empty auto test cases. For example, the boost test regressions crash: ### user-config.jam contains: using gcc : 4.3.2 : /bin/g++-4.exe ; ## cygwin gcc 4.x compiler $ cd /asl/staff/mmarcus/sandbox/boost_libraries/libs/test $ ../../tools/jam/src/bin.cygwinx86/bjam.exe gcc-4.3.2 link=static -q gives: $ ../../tools/jam/src/bin.cygwinx86/bjam.exe gcc-4.3.2 link=static -q ...patience... ...found 1528 targets... ...updating 341 targets... gcc.link ../../bin.v2/libs/test/example/unit_test_example_11.test/gcc-4.3.2/debug/link-static/unit_test_example_11 testing.capture-output ../../bin.v2/libs/test/example/unit_test_example_11.test/gcc-4.3.2/debug/link-static/unit_test_example_11.run ====== BEGIN OUTPUT ====== EXIT STATUS: 53 ====== END OUTPUT ====== (failed-as-expected) ../../bin.v2/libs/test/example/unit_test_example_11.test/gcc-4.3.2/debug/link-static/unit_test_example_11.run **passed** ../../bin.v2/libs/test/example/unit_test_example_11.test/gcc-4.3.2/debug/link-static/unit_test_example_11.test gcc.link ../../bin.v2/libs/test/example/unit_test_example_12.test/gcc-4.3.2/debug/link-static/unit_test_example_12 **passed** ../../bin.v2/libs/test/example/unit_test_example_12.test/gcc-4.3.2/debug/link-static/unit_test_example_12.test gcc.link ../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1 testing.capture-output ../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1.run ====== BEGIN OUTPUT ====== EXIT STATUS: 53 ====== END OUTPUT ====== PATH=//bin://lib://lib32://lib64:$PATH export PATH "../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1" > "../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1.output" 2>&1 status=$? echo >> "../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1.output" echo EXIT STATUS: $status >> "../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1.output" if test $status -eq 0 ; then cp "../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1.output" "../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1.run" fi verbose=0 if test $status -ne 0 ; then verbose=1 fi if test $verbose -eq 1 ; then echo ====== BEGIN OUTPUT ====== cat "../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1.output" echo ====== END OUTPUT ====== fi exit $status ...failed testing.capture-output ../../bin.v2/libs/test/example/est_example1.test/gcc-4.3.2/debug/link-static/est_example1.run... ...failed updating 1 target... ...updated 7 targets... ### Similar problems occur with when I use a manually-compiled gcc-4.3.0. In that case, my output for an empty auto test case looks like: ====== BEGIN OUTPUT ====== Running 1 test case... *** No errors detected 2 [main] any_regular_test 66836 _cygtls::handle_exceptions: Exception: STATUS_ACCESS_VIOLATION 413574 [main] any_regular_test 66836 open_stackdumpfile: Dumping stack trace to any_regular_test.exe.stackdump EXIT STATUS: 35584 ====== END OUTPUT ====== Stepping through in gcc shows that things run fine through the end of main, but then a problem occurs at static destruction time. My gdb skills are not sufficient to give much more info. These problems are new to 1.37.0--I've been using the unit tests successfully up through 1.36.0 (with the alt stack patch). The stack dump file for the manually-compiled gcc-4.3.0 follows. Can someone offer a suggestion? Thanks, Mat ### Exception: STATUS_ACCESS_VIOLATION at eip=610C38B4 eax=00000001 ebx=00000001 ecx=61108B2C edx=00BE0000 esi=61102F64 edi=FFFFFFF9 ebp=0022CAC8 esp=0022CA40 program=c:\asl\staff\mmarcus\sandbox\built_artifacts\test\unit_tests\any_regular\any_regular_test.test\gcc-4.3.0\debug\architecture-x86\asl-dev\instruction-set-i486\link-static\target-os-cygwin\threadapi-pthread\threading-multi\any_regular_test.exe, pid 66836, thread main cs=001B ds=0023 es=0023 fs=003B gs=0000 ss=0023 Stack trace: Frame Function Args 0022CAC8 610C38B4 (004742A0, 00BE2BE0, 00000001, 004311E0) 0022CB58 00428850 (004742A0, 61102EDC, 0022CB78, 610046C2) 0022CB78 0040682F (004737DC, 61004690, 00000000, 0022CBE0) 0022CBA8 610F7DD3 (00000000, 00000000, 0022CBD8, 00000000) 0022CBC8 610E1558 (00000000, 00000000, 0022CD98, 610060E0) 0022CBD8 61004DD1 (00000000, 00BE2580, 00BE0090, 0022CB60) 0022CD98 610060E0 (00000000, 0022CDD0, 61005450, 0022CDD0) 61005450 61004416 (0000009C, A02404C7, E8611021, FFFFFF48) 2046399 [main] any_regular_test 66836 _cygtls::handle_exceptions: Exception: STATUS_ACCESS_VIOLATION 2114906 [main] any_regular_test 66836 _cygtls::handle_exceptions: Error while dumping state (probably corrupted stack)

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[serialization] load-only or save-only types?
by David Abrahams 06 Nov '08

06 Nov '08

Hi, I want to send out instances of one type and receive the same data format but build instances of a different type. Obviously I can just define serialize() for each of them, but can I define only save for the outgoing type and load for the incoming one, causing serialization in the other direction to be a compile-time error? Not a big deal, but it would be more expressive that way. TIA, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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make_shared and allocate_shared for classes with private constructors
by Michael Marcin 06 Nov '08

06 Nov '08

I have some classes that derive from enable_shared_from_this which I've given private constructors and static creation methods which return a shared_ptr. This prevents someone from using the class inappropriately. It seems obvious that at a minimum using make_shared internally here would be an improvement. Unfortunately this requires that make_shared be made a friend for every arity and probably won't work with the variadic template implementation of make_shared. Is it possible to make declaring friendship for make_shared and allocate_shared simpler? I thinking something like serialization does with friend class boost::serialization::access. Thanks, -- Michael Marcin

2 3

location for PDF docs?
by Eric Niebler 06 Nov '08

06 Nov '08

I can't remember if we ever settled on a location for PDF documentation. Did we? And should we make it official by linking to it from boost.org? FWIW, I've uploaded a PDF version of Proto's docs to: http://www.boostpro.com/vault/index.php?directory=PDF%20Documentation Aside: Proto's reference section for 1.37 is /much/ improved. -- Eric Niebler BoostPro Computing http://www.boostpro.com

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[FileSystem] portable Temp, Desktop & Applications directories?
by Jeff Flinn 06 Nov '08

06 Nov '08

Is there any existing facility to get in particular the path to the user's temp directory in FileSystem? I couldn't find one in boost_1_35_0, but I've might have missed it. Any plans for this functionality? On Win and Mac there's getenv TEMP/TmpDir, or is there a better way. Thanks, Jeff

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Reflection?
by Jean-Louis Leroy 06 Nov '08

06 Nov '08

Is runtime reflection going to be available in boost soon? The last I have found on the subject is http://lists.boost.org/Archives/boost/2007/08/126006.php but I see nothing in the sandbox nor the vault. I have toyed with an implementation myself. It supports member variables and functions, multiple and virtual inheritance and object creation. Here is what it looks like. First a small hierarchy: class animal { /* ... */ }; class mammal : public virtual animal { /* ... */ }; class carnivore : public virtual animal{ /* ... */ }; class dog : public mammal, public carnivore{ /* ... */ }; Reflection info is filled like this: reflection_class<animal>::name("animal"); reflection_class<animal>::variable("age", &animal::age); // etc reflection_class<mammal>::name("mammal"); reflection_class<mammal>::base<animal>(virtual_); // etc reflection_class<carnivore>::name("carnivore"); reflection_class<carnivore>::base<animal>(virtual_); // etc reflection_class<dog>::name("dog"); reflection_class<dog>::base<mammal>(); reflection_class<dog>::base<carnivore>(); // a function reflection_class<dog>::function("bark", &dog::bark); // overloaded functions reflection_class<dog>::function<string (dog::*)(void) const>("name", &dog::name); reflection_class<dog>::function<void (dog::*)(const string&)>("name", &dog::name); // constructor reflection_class<dog>::constructor<void* (*)()>(); // etc And here how it's used: animal* pa(new dog); object o(downcast(pa)); // recover dynamic type // access member variable inherited from virtual base `animal' member_variable<int> dog_age(o, "age"); int age = o[dog_age]; // call member function member_function<string (object::*)() const> dog_name(o, "name"); string name = o[dog_name](); // create a dog using default ctor object o("dog"); Ok, there is a bit more to it (e.g. support macros, ambiguity detection, handling of shadowed members, overloaded ctors) but the important part is shown above. All in all it is a foundation upon which one can build multimethods, generic object processing (like Perl's data::Dumper), serialization, object-relational mapping and all sorts of nice tools. Does anybody see interest in this work? Jean-Louis

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Is Boost.Astronomy feasible?
by Mika Heiskanen 06 Nov '08

06 Nov '08

Hello, I would like to think that it would be possible to create a library for common astronomical calculations, and I think boost might be the proper place to create one for the C++ community. First a definition: by common calculations I mean those most relevant to every dat life. For normal people this would pretty much exclude most astronomical calculations except those concerning the sun and the moon. Some examples on what calculations I think would be common are: o sunrise, sunset, noon o sun elevation, azimuth, declination o length of the day o phase of the moon, and whether the visible fraction is increasing or not However, there are some complications: o There are several ways to define twilight times, for example civil, nautical and astronomical. o The sun may set/rise more than once during a day in polar regions, or it may do neither. o What is the definition for the length of the day if sunrise/sunset occurs more than once during a day? o Are separate methods needed for testing whether the given date is of type "polar day" or "polar night" or "midnight sun"? The definitions for the three seem to be a bit ambiguous. For example, it is perfectly possible for the sun to be up at midnight but still to set during the day, in which case you would have "midnight sun" but not necessarily a "polar day", when the sun shines 24h. o Most calculations are intimately tied to the local time, so the API should rely on Boost.Date_time. Many places refer to Meeus's work for the most accurate calculations. The formulas have been ported to C++ in the form of the AA++ (astronomical algorithms) library. However, the library seems to be aimed for experts and there are no easy recipies for solving the common problems mentioned above. The questions I would like to pose are then: o Would a boost::astronomy namespace as implied above be a good addition to boost? o Are there any experts out there who understand the subject matter well enough to provide a robust implementation or atleast guidance on the matter? For example, NOAA provides web based solar position and sunrise calculators. According to the documentation the calculators are based on the work of Meeus. However, there are some clear design issues on how things should be handled in C++ versus the JavaScript embedded into the NOAA pages. Any thoughts on the matter? Regards, --> Mika Heiskanen

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[c++0x] Boost implementations of C++0x standard library components?
by Beman Dawes 05 Nov '08

05 Nov '08

I want to submit an improved timer to Boost. I'd like it to use the C++0x standard library's <chrono> and <ratio> headers. Because it will be many years before such C++0x are universally available, I think Boost should include an implementation of these libraries. Howard Hinnant has kindly contributed his demo implementation of <chrono> and <ratio> as a starting point, so the hard stuff is already done. I'm starting to boostify his code. That brings up questions of header and namespace names. Presumably what we do with these two small headers will set the pattern for any other C++0x standard library headers we include in Boost. Here is a strawman proposal for how we organize C++0x standard library components we choose to add to Boost: * Such libraries go through the regular formal review process, although it will need to be adjusted a bit since the interface is already known and frozen. * C++0x standard library header naming convention is followed. Thus these will be named <chrono> and <ratio> rather than <chrono.hpp> and <ratio.hpp>. * C++0x standard library namespaces are used. Thus namespace std and std::chrono rather than boost and boost::chrono. * Directory structure: boost-root boost c++0x // <ratio>, <chrono>, and other c++0x std lib headers go here ... libs c++0x chrono build doc src // if needed test ratio build doc src // if needed test ... This allows a user to refer to say the ratio header as <boost/c++/ratio>, <c++/ratio>, or just plain <ratio>. The user would have to provide an additional include path of boost-root/boost or boost-root/boost/c++0x for the second and third usages to work. Comments? --Beman

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[MultiIndex] interface comments
by David Abrahams 05 Nov '08

05 Nov '08

Just reading through the docs for this very useful library and I had a few notes: 0. The term /typelist/ (italicized) is used in the tutorial without definition. Do you mean an MPL type sequence, or something else? 1. Seems like the tags functionality could take advantage of Boost.Parameter to provide a nicer interface and save some code. 2. The "shortcuts" save exactly 1 character. Each index of a multi_index_container uses its own iterator types, which are different from those of another indices. As is the rule with STL containers, these iterators are defined as nested types of the index: employee_set::nth_index<1>::type::iterator it= es.get<1>().find("Judy Smith"); <snip> Additionally, multi_index_containers provide shortcut definitions to the iterator types of their constituent indices: employee_set::nth_index_iterator<1>::type it= es.get<1>().find("Judy Smith"); There is a variation of the expression above for use with tags: employee_set::index_iterator<name>::type it= es.get<name>().find("Judy Smith"); // get<1> would also work Notice the column in which "it" appears in both versions. IMO these interfaces should be deprecated (i.e. not documented, and eventually removed) as they provide no readability advantage, hurt learnability, and complicate usage. Regards, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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[threadpool] recursive fork/join (fibers removed)
by k-oli＠gmx.de 05 Nov '08

05 Nov '08

Hello, http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost-… I've uploaded a new version of threadpool - fibers are remove so that fork/join is provided via recursive execution of sub-tasks (enqueued in local worker-queue). One open item is the synchronization of parent-task und sub-task (signaling via condition variables) - maybe solveable via fibers. regards, Oliver

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Is there any need for a math library doing vectors and matrices operations?
by Christophe Riccio 05 Nov '08

05 Nov '08

Hi, For a 3D programmers using vectors and matrices is as common as using integers. Actually, it's probably even more common! For this reason, every 3D programmer relies on a math library but as they usually don't need much … they implement their own basic math library and that fine. However, most of the time a single graphics software could uses several math libraries because it uses several external libraries that each of them use there own math library. It involves: - A lot of unnecessary copy and conversion of data. - Different meanings for overloaded operators. - Unspecified conventions: row major matrix, column major matrix, left or right handed? - Use of poor math libraries. - Several libraries to understand, to learn: a waste of time for trivial and common need! GPU programmers get some really convenient languages to do graphics on GPU. Cg: http://developer.download.nvidia.com/cg/Cg_2.0/2.1.0012/Cg-2.1_October2008_… HLSL: http://msdn.microsoft.com/en-us/library/bb509561(VS.85).aspx<http://msdn.microsoft.com/en-us/library/bb509561%28VS.85%29.aspx> GLSL: http://www.opengl.org/registry/doc/GLSLangSpec.Full.1.30.08.withchanges.pdf These languages are the result of a lot of experimented developers in 3D graphics and are basically the same. I decided to build a C++ math library based on all the rules that those developers agreed to be good rules and it result in GLM: http://glm.g-truc.net. However, those GPU languages provide good features but limited features: No quaternion, no transformation, lot of limitation on types and rules that couldn't apply directly in C++ (swizzle operators). GLM has limitations because it results of too few developers to think about it. I would like to get more feedback and makes it even more useful. I would lie to making it better find more agreement so that one day it could be ready to be integrated to Boost and hopefully to C++ standard. I'm afraid that such kind of library already have been submitted and rejected, I know it need more work but I believe on my approach and I'm not afraid to change the library so that everyone agree it's good. Thanks, Christophe Riccio

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