June 2008 - Boost - lists.boost.org

[inspect] Hall of Shame plus non-ASCII characters
by Beman Dawes 27 Jun '08

27 Jun '08

There is a fresh run of the trunk inspect report up at http://mysite.verizon.net/beman/inspect.html A couple of things are different: * A "Hall of Shame" has been added to highlight what libraries are the worst offenders. I'm open to suggestions as to at what point we should cut off reporting. Maybe limit it to the worst 10 libraries? * A check for non-ASCII characters in source files has been added by Marshall Clow. It is picking up non-ASCII characters in people's names in copyright messages; that's why Boost multi-index looks so bad in the report. We need to come up with preferred approach for those with non-ASCII characters in their names. --Beman

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Trac open bugs - by assignee
by Marshall Clow 27 Jun '08

27 Jun '08

[ 309 open bugs today, 307 Wednesday ] If you are maintaining a library, and have not logged into the trac system at <http://svn.boost.org/trac/boost/>, please do so ASAP. Until you do that, no tickets can be assigned to you, and will remain under "None". Instructions on working with tickets can be found at: <http://svn.boost.org/trac/boost/wiki/TicketWorkflow> and a mapping of user names to "real names" can be found at: <http://svn.boost.org/trac/boost/report/16> Bug summary 40 djowel 30 dgregor 28 az_sw_dude 24 grafik 19 dave 17 bemandawes 15 vladimir_prus 15 agurtovoy 12 no-maintainer 12 jsiek 8 rogeeff 8 johnmaddock 7 anthonyw 5 samuel_krempp 5 kaalus 5 igaztanaga 5 danieljames 4 witt 4 ramey 4 nasonov 4 ebf 4 danielw 3 turkanis 3 troy 3 nesotto 2 shammah 2 marshall 2 jmaurer 2 hkaiser 2 gmelquio 2 garcia 1 urzuga 1 t_schwinger 1 speedsnail 1 pdimov 1 pavol_droba 1 matias 1 jano_gaspar 1 guwi17 1 fcacciola 1 dlwalker 1 andreas_huber69 1 aaron_windsor 1 None None 1907 name of library files on mingw aaron_windsor 1622 Adjacency list needs to handle self-edges correctly agurtovoy 1001 gcc 4.1.2 segfaults on mpl/test/apply.cpp agurtovoy 1051 MPL header ordering triggers bug agurtovoy 1215 Boost 1.34.1_ mpl: Wrong workaround detection using MinGW32 (or.hpp_ line #33) agurtovoy 1317 has_xxx randomly broken in msvc agurtovoy 1469 [mpl] nested typedef of set has two different meanings agurtovoy 1476 always<> is not nullary. agurtovoy 1528 g++ 4.3.0 reports error because of redeclaration of next agurtovoy 1549 Boost.MPL: 'index_of' algorithm is not documented agurtovoy 1568 duplicate include guards agurtovoy 1900 Missing documentation for mpl::print in the MPL library agurtovoy 1916 [mpl] MPL_HAS_XXX_TRAIT_DEF bug in MSVC71 agurtovoy 1992 boost::mpl::zip_view does not support use as a metafunction with ::type agurtovoy 2031 PDF version of MPL reference manual is out-of-date agurtovoy 2041 MPL: more comprehensive test coverage for "fail" situations requiring diagnostics agurtovoy 2042 map insert does not work after an erase in the non-typeof implementation andreas_huber69 1771 Statechart TOC mangled. anthonyw 1154 tss destruction segfaults in conjunction with dlopen/dlclose anthonyw 1470 Boost.Thread: Compilation errors with non-__cdecl calling convention anthonyw 1825 thread.hpp injects windows.h and breaks user application. anthonyw 1826 Auto detection of threadapi and target-os broken under cygwin gcc anthonyw 1867 Missing member functions in shared_mutex (win32) anthonyw 2038 Missing include in tss.hpp anthonyw 2052 Missing xtime overload for timed_lock APIs az_sw_dude 1028 typo in boost header: date_time/time_defs.hpp az_sw_dude 1078 from_iso_string cannot read the output from to_iso_string az_sw_dude 1098 Urgent libboost-date-time1.33.1 : bugs on ia64 ? az_sw_dude 1147 date_time library contains global #define ERROR az_sw_dude 1160 warning: month_format shadows a member of this az_sw_dude 1162 warning: ticks shadows a member of this az_sw_dude 1289 posix_time::time_facet forgets to pass a_ref argument to base class az_sw_dude 1299 change in typedef stringstream_type in format_date_parser.hpp causing compilation error az_sw_dude 1306 invalid docbook in date_period.xml az_sw_dude 1384 Linking problem with date_time library on Visual C++ 2008 Express az_sw_dude 1524 format_date_parser.hpp(221) : cannot convert parameter 1 az_sw_dude 1574 operator<< for boost::posix_time::ptime ignores ostream flags az_sw_dude 1674 date_time::date_formatting.hpp: incorrectly formats year using global locale az_sw_dude 1695 add correct namespace to class to fix compilation bug az_sw_dude 1726 boost/date_time/posix_time/time_formatters.hpp incorrectly formats fractional seconds using global locale az_sw_dude 1740 date_time includes <windows.h> az_sw_dude 1788 local_time::local_time_period streaming operators not implemented az_sw_dude 1859 boost::gregorian::to_tm() doesn't fill in tm_zone on Mac OS X az_sw_dude 1878 Documention Corrections - Various date_time Pages az_sw_dude 1903 [date_time] - 1.34+ c_local_adjustor derefs null pointer for dates >2038 az_sw_dude 1933 special_values not found when compiling date_time/time.hpp az_sw_dude 1934 iterator reference zero when reading time zone [with patch] az_sw_dude 287 wrong usage of ios_base::narrow az_sw_dude 316 date_time type conversion warning az_sw_dude 604 from_ftime incorrectly processes FILETIME filled with zeros az_sw_dude 642 operator<< for gregorian::date_duration not found az_sw_dude 889 Insane Dependencies az_sw_dude 890 date_time library supports only the current dst rule bemandawes 1378 filesystem path invalid name for hidden files (LINUX) bemandawes 1389 filesystem::ostream << boost::format generates operator ambigious error (in MSVC++) bemandawes 1458 Darwin Tiger throws std::runtime_error: locale::facet::_S_create_c_locale name not valid bemandawes 1578 bug in readdir_r_simulator() in a multi-threaded environment bemandawes 1583 Serious flaw in boost::filesystem filename handling (opensuse) bemandawes 1606 filesystem/src/exception.cpp doesn't build with gcc bemandawes 1613 Link Errors against file_system on OS X with Intel Version 10.1 C++ compilers bemandawes 1682 path_traits needs imbue() bemandawes 1701 boost::filesystem::remove_all - segmentation fault with wpath on Linux bemandawes 1711 Boost Serialization export facility broken on gcc 4.1_ 4.2 bemandawes 1767 missing file: boost/filesystem/cerrno.hpp bemandawes 1840 name check functions have different behavior wrt empty string bemandawes 1876 portable_file_name() returns true for '.' and '..' bemandawes 1962 Doesn't measure wall clock time bemandawes 1971 remove_all is not documented bemandawes 1972 boost::filesystem::remove() throws on self referenced symlinks bemandawes 752 directory_iterator doesn't work with catch danieljames 1554 When BOOST_HASH_NO_EXTENSIONS is defined hash doesn't support new string types. danieljames 1555 When BOOST_HASH_NO_EXTENSIONS is defined hash doesn't support boost::system::error_code danieljames 1742 Some bugs in http://www.boost.org/doc/libs/1_35_0 danieljames 1743 Documentation has incorrect Build & Link settings for some libraries danieljames 1923 Unordered move implementation doesn't work in Borland. danielw 1054 Parameter takes an "infinite" amount of time to compile with the Intel compiler. danielw 1097 keyword.hpp generates many warnings C4180: qualifier applied to function type has no meaning; ignored danielw 1387 Review / update docs to reflect changes danielw 1966 Need VC8 workaround dave 1010 linking boost.python on freebsd dave 1019 iterator_facade::pointer should be the return type of operator-> (DR 445) dave 1179 [boost.python] can not export a union in VC2005sp1 dave 1181 [boost.python] can modify enum value dave 1460 Python classes with multiple bases are convertible only to the first class in the lists dave 1482 boost::python::throw_error_already_set should be marked noreturn dave 1516 [python] Failing VC9 regression tests dave 1599 [python] '_set_se_translator': identifier not found dave 1697 [utility][noncopyable] ADL barrier broken by msvc-9.0 dave 1730 No debug libs on Windows by default dave 1851 Issue with proxies and rvalues dave 1860 zip_iterator::value_type should not be reference dave 1887 [doc] input_iterator_archetype is not a valid InputIterator dave 1890 Missing parameters in example code dave 1952 The operation static_cast<std::string>(boost::python::extract<std::string>(...)) crashes Python. Seems to create reference counting problem. dave 2016 wrong default arguments in boost/python/exec.hpp dave 2050 Don't use '--toolset' in documentation dave 865 Use of C++0x keyword as identifier dave 910 gcc strict-aliasing problems with python dgregor 1009 Improper overflow handling in shortest paths algorithms dgregor 1021 [Graph][reverse_graph] Problem using reverse_graph adapter with an adapted user defined graph dgregor 1076 compile error: disconnecting struct with operator()() doesn't work in VS2005 SP1 dgregor 1164 Floyd Warshall broken with unsigned edge weights dgregor 1192 [boostbook] problem when two files have the same name dgregor 1199 configure doesn't work with path containing whitespaces (MacOS X) dgregor 1310 [result_of] const-qualified function pointer doesn't work dgregor 1322 trac rejects patch attachment as spam dgregor 1326 Unable to check graph isomorphism using LEDA adapter dgregor 1391 dominator_tree_test on Borland/CodeGear outputs overly long line dgregor 1630 gcc-4.3: adjacency_list.hpp includes deprecated header dgregor 1910 function::swap should avoid doing memory allocations dgregor 1943 (minor) configuring with header-only libraries. dgregor 1945 Update CMake configuration introduction for CMake 2.6.0 dgregor 1986 Missing IncidenceGraph requirement in topological_sort docs dgregor 1994 headers out of order somewhere in function/functional dgregor 2005 References to the old CVS archive_ instead of the current Subversion one dgregor 375 LEDA graph adaptors do not handle hidden nodes properly dgregor 402 random_vertex/random_edge are unnecessarily inefficient dgregor 403 Document copy_component dgregor 447 reverse_graph and constness of property maps dgregor 556 Bundled graph properties dgregor 708 Dijkstra no_init version should not require VertexListGraph dgregor 732 Johnson All-Pairs needs better "no path" information dgregor 733 Numbered headers don't work with "preferred" syntax dgregor 735 Fruchterman-Reingold grid performance can be improved dgregor 736 Const correctness violation dgregor 738 Memory leaks with signal::connect? dgregor 829 Implicit graph not implement dgregor 852 Problem with Boost and GCC 4.1 djowel 1170 Emit Warnings instead of # symbols in the syntax highlighter djowel 1171 Quickbook title output djowel 1172 non-utf djowel 1176 Space after inline code djowel 1206 Escaping from within code? djowel 1273 CR+LF newlines in position_iterator djowel 1276 spirit problem with _GLIBCXX_DEBUG djowel 1277 Closing section like [pre with } causes Quickbok to crash djowel 1280 sections in imported source files get put inside <para> elements in docbook output djowel 1281 Quickbook produces invalid BoostBook/DocBook XML djowel 1324 tuple should have a swap() that operates element-by-element djowel 1396 wrong result_of invocation around transform_view djowel 1436 [quickbook] inline code inside headings djowel 1484 Quickbook produces illegal docbook for some docinfo fields. djowel 1500 [Spirit/Phoenix] C4512 Compiler warnings from VC8 djowel 1570 Some boost headers aren't ready for gcc 4.3 djowel 1600 duplicate include guard djowel 1601 distane of boost::tuple djowel 1607 Tuple Library Documentation Changes djowel 1610 [MSVC/STLport] [tree/common.hpp] Standard library requirements violation(incomplete type as vector parameter) djowel 1614 vector workaround needed for MSVC9 djowel 1617 spirit gcc-4.3 fix djowel 1619 [Fusion] C4512 warnings from VC9 (Visual Studio 2008) djowel 1651 incorrect typedefs in examples djowel 1763 wrong AST when parser_tag==0 djowel 1764 wrong AST when parser_tag==0 djowel 1844 Quickbook matches forward slashes (for italics) with slashes in links djowel 1864 [Documentation]There is no documentation for repetivive_view djowel 1872 [Spirit2] 'assignment operator could not be generated' warnings from VC9 djowel 1892 boost::spirit::static_ causes link error (using wave) djowel 1893 Documentation Corrections to map.html djowel 1894 fusion\support\tag_of.hpp_ boost::fusion::traits djowel 1920 lexical_cast with tuple target fails_ because of cleared skipws flag djowel 1953 spirit doesn't use quickbook proper djowel 1997 missing include in spirit 'classic' header. djowel 2014 real_p parser produces numerically different results from iostream input operator djowel 2017 leaf_node_d matches leading skip tokens djowel 2034 Problem with nesting templates with same parameter names djowel 2035 Can't make template for a link djowel 2036 Crash with some invalid nested templates specification dlwalker 613 boost/crc.hpp uses non-standard conforming syntax ebf 1507 [variant] C4512 warnings from VC8.0 ebf 1548 [variant][docs]typo: formal arg_ operand_ should be v in times_two arglist ebf 1654 recursive variants do not handle nested variants correctly. ebf 993 Variant should use least common multiple of alignments_ rather than maximum fcacciola 1666 Visualizer for boost::optional garcia 1581 Boost.MultiArray: Resizing bug if the index is not 0-based garcia 1741 Review schedule out of date gmelquio 1886 Typo in Interval documentation gmelquio 1944 Interval library pow function doesn't work with mpq_class and similar grafik 1041 Cygwin requires PATH setting. grafik 1085 Python rules for compiling in Mac OS X grafik 1406 Understanding the Tables outdated grafik 1417 Regresson tests hang in Darwin (Tiger) grafik 1430 Regression fails under Cygwin grafik 1512 Broken link to vacpp in bjam docs. grafik 1576 cannot read non-ASCII output messages grafik 1577 Some commands don't work because hStdInput == 0 grafik 1663 build.bat cannot set/reset ERRORLEVEL grafik 1733 Website layout overlays on IE7 grafik 1735 [website] Wrong HTML on main documentation page. grafik 1738 Boost Jam details and download link grafik 1739 Search box and Google link grafik 1744 [getting started] No information on building static libraries with bjam under Windows grafik 1753 Python docs: bad link to the Jamroot grafik 1776 Documentation page renders incorrectly in Safari 3.1 on OS X grafik 1906 Trac site too hard to find grafik 1927 MacOS (Darwin) should use the -headerpad_max_install_name option grafik 1930 The userman.pdf boost-build documentation is outdated grafik 2020 People grid stretches images grafik 2046 http://www.boost.org/doc/libs/1_35_0/libs/python/doc/v2/pickle.html is missing grafik 616 Boost Jam_ and non english directorys grafik 959 linking fails when Boost is compiled with STLport 5.1.* on Linux (names mismatch) grafik 986 Problem building Python modules on boost 1.34.0 guwi17 1974 ambiguous call to ref in vector_of_vector.hpp when using bind.hpp hkaiser 1079 boost-1.34.0 fails to compile. concept checks not satisfied. hkaiser 1670 wave almost unusably slow on real-world input igaztanaga 1080 boost::interprocess win32 global file mapping issue igaztanaga 1210 interprocess::barrier hangs during second use under linux (boost 1.33.1) igaztanaga 1390 Interpocess: managed shared memory failing completely under OS X igaztanaga 1634 boost::interprocess::vector cannot contain volatile int igaztanaga 1975 windows_shared_memory implicitly commits virtual memory jano_gaspar 1852 copy constructor does not copy capacity jmaurer 351 Diff in state of mersenne_twister gen between GCC3.41 & CW9 jmaurer 599 uniform_01 copies engine instead of using a reference johnmaddock 1081 Empty string rejected as perl-style regex johnmaddock 1451 error: use of C99 long long integer constant johnmaddock 1940 broken links johnmaddock 1988 Boost.Config macros badly added. johnmaddock 2011 Is there a way to extract the member type of a (data) member pointer? johnmaddock 2022 Found crash of boost for characters ' * ' _ ' a* ' _ & " abc** " johnmaddock 2033 STLPort & fpclassify compatibility issue johnmaddock 2048 exception when I create boost::RegEx in destructor code flow jsiek 1531 segfault in dynamic_bitset::reference assign operator jsiek 1540 Poisson distribution very slow for large mean (and may also overflow). jsiek 1755 Boost.tokenizer is broken for wide characters - patch attached jsiek 1798 met an error using boost::tokenizer in multi-times in vs2005_ unicode jsiek 1888 Why doesn't InputIterator require that reference is convertible to value_type? jsiek 1909 Documentation is out of sync jsiek 2037 concept_check fails with types declared in unnamed namespace jsiek 575 Calling subgraph::global_to_local on a root graph jsiek 636 strange compiling problem for transitive_closure jsiek 815 remove_edge core dumps on self-circle jsiek 875 No iterator based constructor for adjacency_matrix jsiek 900 graphml reader namespace handling is broken kaalus 1184 property_tree assignment (operator) bug kaalus 1604 property_tree xml parser doesn't compile with gcc kaalus 1678 Boost.property_tree::read_xml does not parse UNICODE file with BOMs kaalus 1914 Boost.PropertyTree JSON parser in SVN trunk does not compile with Spirit2 changes kaalus 1955 gcc-4.x and gcc-4.3 fixes marshall 1252 [pool] severe overhead with unaligned sizes. marshall 1736 Headers containing non ASCII characters cause MS VC to issue warning 4819 in some locales matias 2018 Error in the documentation chapter "Runtime parameters reference" nasonov 1220 lexical_cast requires RTTI nasonov 1847 Can't compile without <locale> header_ boost::lexical_cast problem nasonov 2045 lexical_cast<std::string> of short unsigned produces warnigns with g++ and -Wsign-promo nasonov 754 boost::any - typeid comparison across shared boundaries nesotto 1754 Illegal HTML in range docs. nesotto 1785 assign::list_of works poorly with class constructors nesotto 1795 [ptr_container] minor documentation typo no-maintainer 1068 Mersenne twister disables streaming for Visual C++ no-maintainer 1222 lambda::ret<T> should declare result_type. no-maintainer 1270 uniform_smallint doesn't compile with lagged_fibonacci random number generators no-maintainer 1515 [lambda] C4512 warnings from VC8.0 no-maintainer 1544 uniform_01 w/ref template param causes ref to ref error no-maintainer 1546 Method boost::random::uniform_int::operator()(engine_ value) is missing no-maintainer 1572 [lambda] smart pointer const-ness affects its contents no-maintainer 1632 Default Interval rounding policies incomplete no-maintainer 1691 [Random] Brokem MSVC workaround no-maintainer 1856 minstd_rand returning different values in 1.35.0 than in 1.34.1 no-maintainer 781 Lambda: (_1 + "y")(string("x")) Doesn't Compile no-maintainer 819 uniform_int<> with type's maximum availaible range error pavol_droba 1152 rle_example fails pdimov 2000 boost/detail/spinlock_sync.hpp incorrectly included for Intel C++ on Linux ramey 1708 Can't serialize class with private destructor ramey 1836 bug in serializing wide character strings ramey 1941 polymorphic archive interface doesn't match other archive interfaces ramey 1973 [gcc43] Backport trunk fixes into release branch rogeeff 1383 signal.h features not found on Mac OS rogeeff 1644 Boost.Test missing documentation file BOOST_CHECK_CLOSE_FRACTION.html rogeeff 1676 Dead links on Boost.Test example documentation. rogeeff 1723 No subprocess can be started in init_unit_test_suite rogeeff 1746 Online documentation for 1.35.0 is out of date for current lib version rogeeff 1839 Test fails if child process exits with non-zero code rogeeff 1866 Typos in Boost Test documentation rogeeff 1869 Typo in Unit Test Framework documentation samuel_krempp 1699 Compile warning about initialization order. samuel_krempp 1801 Typo in documentation. samuel_krempp 2015 boost::format::operator% does not work with anonymous types inside a namespace samuel_krempp 2024 boost::format("%p") % (uint8_t *) str is not like printf("%p"_ str) samuel_krempp 859 boost::format ignores a user defined locale shammah 290 perfomance: memory cleanup for pool takes too long shammah 386 boost::pool_allocator breaks with vector of vectors speedsnail 1138 Problems with TSS and static thread library t_schwinger 1653 wave executable erroneously required for build of function_types lib troy 1981 tests when ceratain build variants turned off troy 2043 windows build hangs in build slave mode troy 2044 windows debug popups in build slave mode turkanis 1579 gzip compressor should model DualUseFilter turkanis 1649 Fix definition of JavaScript menu to avoid long chains of functions turkanis 1656 Consider implementing flush() for symmetric filters urzuga 574 [boost::lambda] Compile error with libstdc++ debug mode vladimir_prus 1132 zero_tokens clarification vladimir_prus 1165 more quoting problems vladimir_prus 1274 Useless error message vladimir_prus 1527 [program_options] Second (and subsequent) lines in tabbed text not aligned correctly vladimir_prus 1537 no value given in 'mysql_password =' vladimir_prus 1584 cryptic bbv2 error building quickbook vladimir_prus 1587 [program_options] crashes if value part missing in external configuration file vladimir_prus 1645 Invalid unicode support for default_value vladimir_prus 1679 added 4-way universal binary support from mac osx (ppc_ ppc64_ i386_ x86_64) vladimir_prus 1967 bjam bug? iostreams + zlib won't build for VC8 or MinGW with small hack to Jamfile.v2 vladimir_prus 2025 doxygen.jam does not quote argument properly vladimir_prus 2030 stdlibs=sun-stlport fails vladimir_prus 469 multitoken broken vladimir_prus 689 [program_options] Endless loop with long default arguments vladimir_prus 850 program_options strips off escaped quotes in some situations witt 583 Fixes for build on IBM pSeries for AIX and Linux witt 834 Homepage regression links witt 957 The "Getting Started" page does not mention the stdlib option witt 973 zip_iterator has value_type == reference -- -- Marshall Marshall Clow Qualcomm, Inc. <mailto:mclow@qualcomm.com> The famous British scientist, Lord Kelvin, said: "When you measure what you are speaking about and express it in numbers, you know something about it, but when you cannot (or do not) measure it, when you cannot (or do not) express it in numbers, then your knowledge is of a meagre and unsatisfactory kind."

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[serialization] std::exception: unregistered void cast
by Thorsten Ottosen 27 Jun '08

27 Jun '08

Hi, My serialization test have started to fail with the above exception; I don't recall having done anything special on my side: http://tinyurl.com/69tgyv Has the way you serialize class hierarchies changed lately? Thanks -Thorsten

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Re: [boost] [asio] failure in ~wrapped_handler
by Dean Michael C. Berris 27 Jun '08

27 Jun '08

Of course I should have attached the trace... ;) -- Dean Michael Berris Software Engineer, Friendster, Inc. > -----Original Message----- > From: Dean Michael C. Berris > Sent: Friday, June 27, 2008 5:40 PM > To: 'boost(a)lists.boost.org' > Subject: [asio] failure in ~wrapped_handler > > Hi everyone, > > I recently ran into a problem with Boost.Asio while using a > slightly modified version of the HTTP 2 example server. The > debugger trace (attached) shows where a segfault had occurred > in the code. > > The short of it is that when ~wrapped_handler is called, the > call to boost::detail::atomic_exchange_and_add fails when > boost::detail::sp_counted_base::release is invoked. It occurs > when a handler_wrapper is deleted/destructed > (~handler_wrapper is called) in the strand_service. > > I'm just wondering what could be causing this -- it's worth > noting that under not-so-heavy load, the problem does not > manifest itself; but soon enough when the load on the server > goes up (more incoming connections) the server crashes consistently. > > Any pointers where I should be looking? I'm using Boost.Trunk > revision number 43296. > > -- > Dean Michael Berris > Software Engineer, Friendster, Inc.

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[thread] Backwards compatibility for timed_lock?
by Chris Newbold 26 Jun '08

26 Jun '08

We're in the process of upgrading to 1.35 and have discovered that there are no timed_lock() overloads accepting the old xtime structure. Was this intentional or an oversight? It isn't mentioned in the list of "breaking changes" in the 1.35 release notes. For example, timed_wait() does have overloads for xtime... -Chris

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[type traits] possible bug in boost::is_convertible for types with private copy constructors
by Daniel James 26 Jun '08

26 Jun '08

>From the move semantics thread: 2008/6/24 David Abrahams <dave(a)boostpro.com>: > Daniel James wrote: >> It mostly works. I've found two problems so far. Firstly, >> is_convertible didn't work for the type, > > You found a bug in is_convertible? I don't know if it's a bug. The example below fails to compile. #include <boost/type_traits/is_convertible.hpp> template <typename T> struct move_from {}; class Y { Y(Y& rhs); public: Y(move_from<Y>) {} }; bool const r = boost::is_convertible<move_from<Y>, Y>::value;

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[graph] multiplicative spanner code
by Dimitrios Michail 26 Jun '08

26 Jun '08

Hi, I have written a small piece of code which computes a 2k-1 multiplicative spanner (k is an integer parameter) of undirected weighted graphs. This spanner is simply a subgraph of an input graph which preserves shortest path distances up to a 2k-1 factor, that is the shortest path from u to v in the spanner is at most 2k-1 times the shortest path from u to v in the original graph. The main benefit is that there is always a 2k-1 spanner with O(n^{1+1/k}) edges. The algorithm is due to Althoefer, Das, Dobkin, Joseph and Soares. It is a simple generalization of Kruskal's algorithm (thus I used Kruskal's algorithm as a template). While not the fastest possible, it is simple and elegant. Is there any place where I could upload my code for interested people to review and comment? Best, Dimitris

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Deprecate BOOST_STATIC_ASSERT?
by David Abrahams 26 Jun '08

26 Jun '08

Yesterday someone on the user's list posted a message (http://article.gmane.org/gmane.comp.lib.boost.user/36884) about a "compilation error in the boost code:" s-test.h:49: instantiated from here /usr/include/boost/archive/detail/oserializer.hpp:567: error: invalid application of 'sizeof' to incomplete type 'boost::STATIC_ASSERTION_FAILURE<false>' make: *** [stest] Error 1 and proceeded to try to analyze the BOOST_STATIC_ASSERT implementation to see what was wrong with it. Granted, most people figure out what a static assertion is supposed to be, but still, the error message gave no clue about what might have gone wrong... no clue to the user, and no clue to anyone reading his posting, unless they were going to look up the line in the source file... oops, I take it back. My copy of oserializer.hpp doesn't even have a line 567, and the posting doesn't indicate which version the user has. For several releases now we've had a suite of static assertion tools that give far superior error messages to what BOOST_STATIC_ASSERT can provide (http://www.boost.org/doc/libs/1_35_0/libs/mpl/doc/refmanual/asserts.html) I think <radical-idea>it's time to deprecate BOOST_STATIC_ASSERT</radical-idea> or at *least* put a prominent note in its documentation directing people at the BOOST_MPL_ASSERT macros. Thoughts? -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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function based associative generator
by Dean Michael Berris 26 Jun '08

26 Jun '08

Hi Everyone, I've recently been playing around with a relatively simple idea: creating a generic associative generator. For some background, here's a simple problem (which is quite common in mathematics): I want to be able to pull out the nth fibonacci number in the fibonacci sequence. To do this, the traditional implementation in C++ would be to create a function that yields the nth fibonacci number. This seems fine, because as C++ programmers we would be used to the notion of using functions. However, the traditional notion of a sequence in mathematics is a collection of values that can be indexed by a subscript. Consider: struct fibonacci { int operator () (int n) const { // ... }; }; boost::generator<int, int> const & fib = boost::generator<int, int>(fibonacci()); std::cout << fib[1] << std::endl; // prints 1st fibonacci number std::cout << fib[2] << std::endl; // prints 2nd fibonacci number ... Now consider that you want to deal with the generator using an STL algorithm: std::copy(fib.begin(), fib.end(), ostream_iterator<int>(std::cout, " ")); // prints the infinite sequence The iterator implementation requires that the InputType (in this case, the second 'int' template parameter to the generator) be default constructable and has a defined prefix and/or postfix increment operator. The iterator models an InputIterator. Given this, I've attached the implementation which I'm opening up for comments. If there is interest in this utility, I'm willing to write documentation and submit it for a formal review. The basic idea for this utility is to map a non-void unary function to a generator interface that provides an associative index operator (operator[]) which passes the sole argument as the argument to the wrapped function. This utility requires only the Boost.Function library, and has been tested with MSVC 2008 Express Edition. Have a good one, and I hope this helps! -- Dean Michael C. Berris Software Engineer, Friendster, Inc.

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[move semantics] Containers supporting movable-only types
by Ion Gaztañaga 26 Jun '08

26 Jun '08

Hi to all, I committed to trunk some days ago (and I plan to merge them to the release branch) some changes in Interprocess containers so that they can take advantage of C++0x rvalue references of gcc 4.3. The goal is that anyone experimenting with compilers with rvalue references (gcc 4.3 for now) can take advantage of containers that can hold movable-only types. Most of these containers (list, map/set/multimap/multiset, slist) are based on Intrusive containers. Vector and deque have more code and a move-aware vector is specially useful to achieve efficient associative ordered vectors like flat_map/flat_set/flat_multimap/flat_multiset. Current move-emulation is still based on Interprocess' own types. For Boost 1.37 I would like to change move emulation to a general Boost.Move library (if that library is ready). With new containers (forward_list) in the standard and having move-aware containers in Interprocess, I was wondering if it would be a good idea to move those containers outside Interprocess. In the future we could make those containers compatible with Scoped Allocators (2554, http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2554.pdf) Opinions? Regards, Ion

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