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Date Time lib and time_t
by Matt Schuckmann 28 Jul '04

28 Jul '04

Has anybody ever implimented a to_time_t function/method for the ptime class to create a time_t from a ptime. I tried doing it similar to the way from_time_t does it but I'm not getting the right answer. It's nice that you can convert from a time_t for use with legacy code but sometimes you need to go back the other way. Herer is my to_time_t function that does not appear to be working inline std::time_t to_time_t(ptime t) { if( t == neg_infin ) return 0; else if( t == pos_infin ) return LONG_MAX; ptime start(gregorian::date(1970,1,1),time_duration(0,0,0)); return (t-start).total_seconds(); } Thanks,

2 2

RE: [Boost-users] Re: Running boost::thread compiled on w2k on XP
by Paul Rose 28 Jul '04

28 Jul '04

This also isn't exactly what you are looking for, but I took built your test.cpp on vc7.1 running on windows XP using boost 1.31 (also built with vc7.1 running on windows XP). Both the debug (using boost_thread-vc71-mt-gd-1_31.dll) and the release (using boost_thread-vc71-mt-1_31.dll) builds of test.cpp worked fine. My boost dlls were built with all default settings (except I used the alternate namespace hack for boost::signals since we also use Qt). I don't have a boost 1.31 built on win2k to try. > >Perhaps I should add that I am using version 1.31 of boost. I have also >discovered that it seems (it might be an illusion, you never know) to work >when I compile against boost_thread-vc71-mt-gd-1_31.lib, but not against >the release lib boost_thread-vc71-mt-1_31.lib. >/Ragnar Ouchterlony _________________________________________________________________ Overwhelmed by debt? Find out how to Dig Yourself Out of Debt from MSN Money. http://special.msn.com/money/0407debt.armx

1 0

[boost.build] Patch for python.jam
by Markus Schöpflin 28 Jul '04

28 Jul '04

Hello, attached is a patch for pyhton.jam which allows to use python installation on Unix which have been configured with different prefix and exec-prefix. Currently this is not supported by boost.build. The patch simply adds the missing include directory to the compiler command line as recommended in http://www.python.org/doc/2.3.4/api/includes.html . After applying the patch you can either use bjam -sPYTHON_ROOT=<prefix> or bjam -sPYTHON_ROOT=<prefix> -sPYTHON_EXEC_ROOT=<exec prefix> Markus --- net/src/orig/boost_1_31_0/tools/build/v1/python.jam 2004-01-28 23:52:25.000000000 +0100 +++ local/src/boost_1_31_0/tools/build/v1/python.jam 2004-07-28 16:15:37.000000000 +0200 @@ -118,7 +118,7 @@ { PYTHON_ROOT ?= /usr/local ; PYTHON_ROOT = $(PYTHON_ROOT:J=" ") ; - PYTHON_INCLUDES ?= $(PYTHON_ROOT)/include/python$(PYTHON_VERSION) ; + PYTHON_INCLUDES ?= $(PYTHON_ROOT)/include/python$(PYTHON_VERSION) $(PYTHON_EXEC_ROOT)/include/python$(PYTHON_VERSION) ; PYTHON_LIB_PATH ?= $(PYTHON_ROOT)/lib/python$(PYTHON_VERSION)/config ; PYTHON_PROPERTIES ?=

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RE: [Boost-users] Re: Bjam- racking my brain
by Brian Braatz 28 Jul '04

28 Jul '04

> > Brian Braatz wrote: > > > Any help would be appreciated, tomorrow afternoon I am going to go back > > at it, and this time I might "get all medieval" about things :) > Rene Rivera Wrote: > build/v2 is not used for building Boost. It's the experimental, and > under development, next version of Boost.Build. If you plan on using > BBv2 read its separate documentation at > boost-root/tools/build/v2/index_v2.html I am sorry - I am confused and am trying to find my way out: *- What is listed for download on sourceforge does not reference a version of build v1 or bjam v1 or what have you. ( I am confused as to how to get the older version) * when I build the code in jam_src and run it- it reports: Boost.Jam Version 3.1.8. OS=NT. This is the same version I used to build boost with (successfully) with vc7.1. I am using the source for bjam included in the 1.31 release of boost * when I try to build boost with a simple bjam stage at the root dir of boost, it succeeds * when I double check the BOOST_ROOT env var with a dir command- it shows me the right dir * my TOOLS envvar is set to TOOLS=vc7.1 This was necessary before being able to build boost * when I CD into the HELLO example for bjam and try a Bjam I GET warning: no toolsets are configured. warning: you won't be able to build C++ programs. warning: please consult the documentation. C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:1073: in construct from module object(exe-t arget-class)@1 error: unable to construct ./hello C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:914: in object(exe-target-class)(a)1.generate from module object(exe-target-class)@1 C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:510: in generate-really from module object( main-target)@1 C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:483: in object(main-target)(a)1.generate from module object(main-target)@1 C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:179: in object(project-target)(a)1.generate f rom module object(project-target)@1 C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2\build-system. jam:160: in load from module build-system C:\Data\Rmtg\Root\_Common\_Lib\Boost\V_1_31\tools\build\v2\example\..\ke rnel\modules.jam:259: in import from module modu les C:\Data\Rmtg\Root\_Common\_Lib\Boost\V_1_31\tools\build\v2\example\..\ke rnel\bootstrap.jam:120: in boost-build from modu le C:\Data\Rmtg\Root\_Common\_Lib\Boost\V_1_31\tools\build\v2\example\boost -build.jam:2: in module scope from module When I TRY: bjam -sTOOLS=vc7.1 bjam "-sTOOLS=vc7.1" bjam debug bjam release bjam "-sTOOLS=vc7.1" debug bjam "-sTOOLS=vc7.1" release I always get the above errors If I COPY the files in \tools\build\v2\example\hello to the ROOT of boost (and overwrite the jam file there)- IT DOES BUILD PROPERLY I have build bjam and stepped through it in the IDE and was not able to make much of what the source was doing (other than it looks like a lot of recursive parsing of files) (spent most of my evening yesterday doing that. MY QUESTIONS: * Which is the right version of boost to be running here? * does the \tools\build\v2\example\hello sample bjam compile for anyone else? (i.e. is it broken?) * is there a good sample of a simple working example for bjam somewhere else? * Any ideas on why I can BUILD BOOST but not any of the subprojects (everything else I have tried has the same problems) * How do you folks debug this thing- ****any**** techniques would be helpful * is the toolsets it is complaining about the COMPILER (i.e. TOOLS envvar?) or is it something else entirely? * HELP ! :) I am doing this pain because I am trying to get boost defined as the standard in my company (It is within my power to do that). I would also like to use the bjam tool as our standard build tool, but I FIRST need to figure out how to build projects with it (grin). Thanks to anyone for thoughts or things to try. Thanks Brian C Braatz

2 1

Difference in adjacency_list
by Daniele Carlucci 27 Jul '04

27 Jul '04

Hi, I'm a newby. Anyone can explain me the difference between: typedef adjacency_list<listS, vecS, undirectedS... and typedef adjacency_list<vecS, vecS, undirectedS... Thanks Daniele

3 4

Bjam- racking my brain
by Brian Braatz 27 Jul '04

27 Jul '04

For the last several days (a few hours each day) I have been trying to get the \tools\build\v2\example\hello sample to build with bjam- (windows XP, vc7.1) I CAN build boost from the command line, but when I move into the \tools\build\v2\example\hello dir and try various combinations of bjam (with and without -sTools=vc7.1 etc..) I get the same error no matter what I do. I took the bjam sources and compiled a debug version in the Visual Studio IDE, and have spent the evening stepping through the code and reading the docs. This is one of these things I think that I just have to completely internalize how this thing works before I will crack this. What I am asking for from this list: * Any basic advice on debugging what bjam is doing * any basic advice or good sample that is a bare and working bjam project to look at * This is weird to me, as the ENV var for the toolset DOES work for building boost itself * I feel like I am missing something obvious and stupid, anyone who wishes to point out what dumb thing I missed, please go at it :) * any help in looking at this output: C:\Data\Rmtg\Root\_Common\_Lib\Boost\V_1_31\tools\build\v2\example\hello >bjam warning: no toolsets are configured. warning: you won't be able to build C++ programs. warning: please consult the documentation. C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:1073: in construct from module object(exe-t arget-class)@1 error: unable to construct ./hello C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:914: in object(exe-target-class)(a)1.generate from module object(exe-target-class)@1 C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:510: in generate-really from module object( main-target)@1 C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:483: in object(main-target)(a)1.generate from module object(main-target)@1 C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2/build\targets .jam:179: in object(project-target)(a)1.generate f rom module object(project-target)@1 C:/Data/Rmtg/Root/_Common/_Lib/Boost/V_1_31/tools/build/v2\build-system. jam:160: in load from module build-system C:\Data\Rmtg\Root\_Common\_Lib\Boost\V_1_31\tools\build\v2\example\..\ke rnel\modules.jam:259: in import from module modu les C:\Data\Rmtg\Root\_Common\_Lib\Boost\V_1_31\tools\build\v2\example\..\ke rnel\bootstrap.jam:120: in boost-build from modu le C:\Data\Rmtg\Root\_Common\_Lib\Boost\V_1_31\tools\build\v2\example\boost -build.jam:2: in module scope from module C:\Data\Rmtg\Root\_Common\_Lib\Boost\V_1_31\tools\build\v2\example\hello >set TOOLs TOOLS=vc7.1 Any help would be appreciated, tomorrow afternoon I am going to go back at it, and this time I might "get all medieval" about things :)

2 1

long long support with GCC
by Aaron W. LaFramboise 27 Jul '04

27 Jul '04

Hi, As I'm sure you know, long long and unsigned long long are supported by GCC in C++. However, -std=c++98 (not quite sure why, to be honest) and -pedantic cause lots of warnings and errors to be generated in the Boost headers when long long is used. In my project, it is desirable to use these flags for other reasons, but the effect these flags have on the Boost headers is decidedly undesirable. So far, I've been wrapping the Boost headers in forwarding headers that mark the Boost headers as system headers so that they compile without warning or error. Is there any disadvantage to doing this? GCC supports long long even with the above options, but only if __extension__ is used. I notice that there a Boost-standard 64bit type, boost::int64_t. Is there some reason that this can't be typedef'ed using the GCC extension, and then this identifier used in all places where 'long long' is being used? Are there type system rules that prevent this, or some other reason? Thank you for your consideration, Aaron W. LaFramboise

4 6

building boost on vc7.1 with stlport
by tweety 26 Jul '04

26 Jul '04

i first compiled (succesfully) stlport 4.6.2. then i ran "bjam "-sTOOLS=vc7.1-stlport" install" and it failed compiling the regex library. then i manually went to the libs\regex\build folder and ran "nmake /f vc7.1-stlport clean install" and it compiled the first thing ok and the 2nd time around threw a LOT of linker errors (well, only ~49, but they're stl-style-long :D). I set correctly the STLPORT_VERSION and the STLPORT_PATH env vars, the tools were loaded ok, the INCLUDE env var had stlport's include dir first... AND IT COMPILED OK the first one... here's a screenshot of the last page of errors. please help me... winstances.obj : error LNK2019: unresolved external symbol "__declspec(dllimport ) public: __thiscall _STL::basic_string<wchar_t,class _STL::char_traits<wchar_t> ,class _STL::allocator<wchar_t> >::basic_string<wchar_t,class _STL::char_traits< wchar_t>,class _STL::allocator<wchar_t> >(wchar_t const *,unsigned int,class _ST L::allocator<wchar_t> const &)" (__imp_??0?$basic_string@_WV?$char_traits@_W@_ST L@@V?$allocator@_W@2@@_STL@@QAE@PB_WIABV?$allocator@_W@1@@Z) referenced in funct ion "public: class _STL::basic_string<wchar_t,class _STL::char_traits<wchar_t>,c lass _STL::allocator<wchar_t> > __fastcall boost::reg_expression<wchar_t,class b oost::regex_traits<wchar_t>,class _STL::allocator<wchar_t> >::str(void)const " ( ?str@?$reg_expression@_WV?$regex_traits@_W@boost@@V?$allocator@_W@_STL@@@boo st@@ QBI?AV?$basic_string@_WV?$char_traits@_W@_STL@@V?$allocator@_W@2@@_STL@@XZ) winstances.obj : error LNK2019: unresolved external symbol "__declspec(dllimport ) public: int __thiscall _STL::basic_string<wchar_t,class _STL::char_traits<wcha r_t>,class _STL::allocator<wchar_t> >::compare(class _STL::basic_string<wchar_t, class _STL::char_traits<wchar_t>,class _STL::allocator<wchar_t> > const &)const " (__imp_?compare@?$basic_string@_WV?$char_traits@_W@_STL@@V?$allocator@_W@2@@ _S TL@@QBEHABV12@@Z) referenced in function "public: int __fastcall boost::reg_expr ession<wchar_t,class boost::regex_traits<wchar_t>,class _STL::allocator<wchar_t> >::compare(class boost::reg_expression<wchar_t,class boost::regex_traits<wchar_ t>,class _STL::allocator<wchar_t> > const &)const " (?compare@?$reg_expression@_ WV?$regex_traits@_W@boost@@V?$allocator@_W@_STL@@@boost@@QBIHABV12@@Z) winstances.obj : error LNK2019: unresolved external symbol "__declspec(dllimport ) public: class _STL::basic_string<wchar_t,class _STL::char_traits<wchar_t>,clas s _STL::allocator<wchar_t> > & __thiscall _STL::basic_string<wchar_t,class _STL: :char_traits<wchar_t>,class _STL::allocator<wchar_t> >::assign(unsigned int,wcha r_t)" (__imp_?assign@?$basic_string@_WV?$char_traits@_W@_STL@@V?$allocator@_W@2@ @_STL@@QAEAAV12@I_W@Z) referenced in function "private: struct boost::re_detail: :re_syntax_base * __fastcall boost::reg_expression<wchar_t,class boost::regex_tr aits<wchar_t>,class _STL::allocator<wchar_t> >::compile_set_aux(class boost::re_ detail::jstack<class _STL::basic_string<wchar_t,class _STL::char_traits<wchar_t> ,class _STL::allocator<wchar_t> >,class _STL::allocator<wchar_t> > &,class boost ::re_detail::jstack<class _STL::basic_string<wchar_t,class _STL::char_traits<wch ar_t>,class _STL::allocator<wchar_t> >,class _STL::allocator<wchar_t> > &,class boost::re_detail::jstack<unsigned long,class _STL::allocator<wchar_t> > &,class boost::re_detail::jstack<class _STL::basic_string<wchar_t,class _STL::char_trait s<wchar_t>,class _STL::allocator<wchar_t> >,class _STL::allocator<wchar_t> > &,b ool,struct boost::re_detail::_narrow_type const &)" (?compile_set_aux@?$reg_expr ession@_WV?$regex_traits@_W@boost@@V?$allocator@_W@_STL@@@boost@@AAIPAUre_sy ntax _base@re_detail@2@AAV?$jstack@V?$basic_string@_WV?$char_traits@_W@_STL@@V?$a lloc ator@_W@2@@_STL@@V?$allocator@_W@2@@42@0AAV?$jstack@KV?$allocator@_W@_STL@@@ 42@0 _NABU_narrow_type@42@@Z) vc71-stlport/boost_regex-vc71-mt-p-1_31.dll : fatal error LNK1120: 49 unresolved externals NMAKE : fatal error U1077: 'link' : return code '0x460' Stop. ---------------------------------- Peace and love, Tweety mitea(a)sympatico.ca - tweety_04_01(a)users.sourceforge.net YahooID: tweety_04_01

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RE: [Boost-users] using boost::shared_ptr with boost::signal
by Ben Hutchings 26 Jul '04

26 Jul '04

Oliver Kowalke <oliver.kowalke(a)t-online.de> wrote: > Hi, > > I want to use boost::shared_ptr with boost::signal. > > class A > { > private: > int _i; > public: > A() : _i( 0) {} > > void operator()( int, std::string & s) > { i+= 1; } > > void operator()( std::string & s, int) > { i+= 2; } > }; > > boost::shared_ptr< A > a( new A() ); > boost::signal< void( int, std::string &) > rsig; > boost::singal< void( std::string &, int) > lsig; > > rsig.connect( a); > lsig.connect( a); > > rsig(0,"called from right side"); > lsig("called from left side",0); > > Because a is a smart_ptr this code would not compile because > operator() is not a member function. If I dereference the smart > pointer when I connect to signal, changes of a are never know > by the other signal instance. > Maybe I can use a proxy class which aggregates the smart pointer > but maybe there is a better solution?! As a general rule, functors are expected to be copiable and not to have mutable state of their own. So how about putting the shared_ptr inside A instead: class A { private: boost::shared_ptr<int> _i; public: A() : _i(new int(0)) {} void operator()(int, std::string & s) { *_i += 1; } void operator()(std::string & s, int) { *_i += 2; } }; A a;

1 0

regex bug (regex_search throws bad_expression)
by Adam Molnar 26 Jul '04

26 Jul '04

hi! using the latest regex patch and vc7.1 i've accidentally encountered the following: ... regex re("([^\n]*\\n+\\s+)+NEEDEDSUBITEM2:[^\\s]"); bool matched = regex_search(text, re); // bad_expression ... i figured out those \\s -s may cause the problem. sample text attached. and one question: having "DATA.*?ITEM1(ITEM2)?" and an input like "DATA ITEM1 ITEM1ITEM2" should ITEM2 be extracted? i think it would be good to make a note on this case in the doc. yours, adam begin 666 match_test.txt M#0I)5$5-5%E014$Z#0H@(" @4U5"251%33$Z('AX> T*#0H@(" @3D5%1$5$ M4U5"251%33$Z(" @('AX>'@-"B @("!.145$141354))5$5-.B @("!X>'AX M#0H-"DE414U465!%0CH-"B @("!354))5$5-,3H@>'AX#0H-"B @("!.145$ M141354))5$5-,3H@(" @>'AX> T*(" @($Y%141%1%-50DE414TR.B @("!X '>'AX#0H-"@`` ` end

3 4

Building boost::fs to a dll
by boost＠dalvander.com 26 Jul '04

26 Jul '04

Is it possible to build boost::filesystem to a dll instead of creating a static linked library? // Anders Dalvander

2 1

C++ Template Metaprogramming
by David Abrahams 25 Jul '04

25 Jul '04

For the past year Aleksey Gurtovoy and I have been working on a new book, titled _C++ Template Metaprogramming: Concepts, Tools and Techniques from Boost and Beyond_. The book has recently entered copyediting. If you're interested you can peruse some sample chapters at http://boost-consulting.com/mplbook. Regards, Dave -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

5 10

Building boost into a single dll
by boost＠dalvander.com 24 Jul '04

24 Jul '04

Is it possible to build all (or some specified) boost libraries into one single dll? // Anders Dalvander

1 0

Newbie -- Regex, Unicode, XCode and MacOSX
by Steve Moore 23 Jul '04

23 Jul '04

Hello. I'm trying to incorporate Unicode regex searching in a little app I'm doing. I'm building using XCode 1.2 on MacOSX 10.3.4. The problem I'm having is that I can't seem to get boost's regex to incorporate unicode or wide-character support. In <boost/config/platform/macos.hpp> there is the line #define BOOST_NO_CWCHAR which seems to disable allowance for unicode by causing boost::wregex and boost::wcmatch symbols to not be typedef-ed. A test app. shows that these symbols are defined when I build using Codewarrior. So I'm wondering how to get unicode support for regex using XCode (gcc) on a MacOSX machine. Any suggestions? Thanks 10^6, STeve Moore.

2 3

Don't seed() mersenne_twister RNG with 0
by Benoît SIBAUD 23 Jul '04

23 Jul '04

Hi, a seed(0) with a mersenne_twister (like mt11213b or mt19937) aborts on some assertion (tested on boost 1.31). boost/random/linear_congruential.hpp:61: boost::random::linear_congruential<IntType, a, c, m, val>::linear_congruential(IntType) [with IntType = uint32_t, IntType a = 69069, IntType c = 0, IntType m = 0, IntType val = 0]: Assertion `c || x0' failed. mersenne_twister::seed(x) calls linear_congruential<uint32_t, 69069, 0, 0, /* unknown */ 0>(x), which asserts(0 || x). So x must be non-zero. I didn't see it in the doc, but I think it would be a good thing to have it written down, or to have mersenne_twister::seed() modified to avoid the assertion. Regards, -- Benoît Sibaud

1 1

filesystem and existing files
by Russell Hind 23 Jul '04

23 Jul '04

With filesystem, you can do filesystem::path P(....); filesystem::ofstream S; if (!filesystem::exists(P)) { S.open(P); } But isn't there a race condition here which could lead to a file created by another process being wiped out, or added to? Is there a way to get ofstream::open to fail if the file already exists? It succeeds on VC7.1 but in some situations I don't want it to succeed. Cheers Russell

2 4

Looking for some help with boost::thread::sleep()
by Kutch, Patrick G 23 Jul '04

23 Jul '04

I am used to putting in quick sleep() statements in my worker threads, usually a sleep(0) just to give up a timeslice, or maybe a sleep(1). Of course boost::thread::sleep takes an xtime object not a milliseconds value, so I wrote a small routine to simulate the sleep() statement using boost::thread::sleep: void inline UtilitySleep(long milliSeconds) { const int NANOSECONDS_PER_MILLISECOND = 1000000; if (0 == milliSeconds) { boost::thread::yield(); // just do a yield return; } boost::xtime time; int sec = 0; // if larger than 1 sec, do some voodoo for the boost::xtime struct if (milliSeconds >= 1000) { // convert ms > 1000 into secs + remaining ms int secs = milliSeconds /1000; milliSeconds = milliSeconds - secs*1000; sec += secs; } milliSeconds*=NANOSECONDS_PER_MILLISECOND; // normal boost time sleep stuff // get current time boost::xtime_get(&time,boost::TIME_UTC); // add # of desired secs and ms time.nsec+=milliSeconds; time.sec+= sec; // sleep until that time boost::thread::sleep(time); } It seems to always work fine unde Windows, however occasionally under Linux it appears that if I use a small value, such as sleep(2) that sometimes it takes longer to setup the values and call boost::thread:sleep() and I end up passing an xtime value that has already passed, basically blocking the thread forever. Anybody have any advice for me? Thanx! - Patrick

1 0

Peculiar uBLAS compile error...
by Nicholas Andrews 23 Jul '04

23 Jul '04

Hi, I have the following c++ function: void multi_state_kf::correction(const vector<double>& obs, const matrix<double>& dev) { compute_gain(dev); vector<double> temp = (m*obs-newX*m); x=newX+prod(temp,K); matrix<double> T=identity_matrix<double>(3,3)-K*m; matrix<double> temp2=prod(T,newP); matrix<double> temp3=prod(K,dev); P=prod(temp2,trans(T))+prod(temp3,trans(K)); } The syntax is completely hacked together as this is my first attempt at using boost's uBLAS, but it got rid of most of my errors except this one: \boost\numeric\ublas\functional.hpp(190): error C2440: '=' : cannot convert from 'const boost::numeric::ublas::matrix_binary_scalar2<E1,E2,F>::value_type' to 'double' (...) The odd (for me) part is that even when I remove all boost function calls from the function the compile error still shows up and it points me to a line in the functional.hpp file. So 1. Does anyone know what could be causing this compile error? 2. What's a better way of writing this function? Thanks in advance, Nick

1 0

test failure rate and usage
by JHAYNBERG＠cooperneff.com 22 Jul '04

22 Jul '04

I wanted to use the Boost smart_ptr classes on Solaris 8/Workshop 7 and RedHat E3/gcc 3.23. So, I downloaded the boost src (and jam and boost.build) and built the entire package. After seeing many test failures, I discovered on the regression test page that no compiler achieves 100% pass rate and some are about 30%. I have 2 questions. One, in general, how does one know when it is "safe" to use a boost library on a particular platform? For example, if a platform's failure rate is 15%, should boost be used? And, two, with just the boost source (without building any libraries), I was able to use the boost::shared_ptr in my Solaris application by merely including the right header. Apparently, I don't need to build boost to use shared_ptr which leads me to ask, in general, how do one know when a library is needed (or not needed)? Shouldn't the fact that boost is mainly templates mean there should be little or no implementation (i.e. code that needs to be compiled into a library)? For example, many template libraries are provided as header-only solutions. Thanks! Jay Haynberg Software Engineer This message and any attachments (the "message") is intended solely for the addressees and is confidential. If you receive this message in error, please delete it and immediately notify the sender. Any use not in accord with its purpose, any dissemination or disclosure, either whole or partial, is prohibited except formal approval. The internet can not guarantee the integrity of this message. BNP PARIBAS (and its subsidiaries) shall (will) not therefore be liable for the message if modified. --------------------------------------------- Ce message et toutes les pieces jointes (ci-apres le "message") sont etablis a l'intention exclusive de ses destinataires et sont confidentiels. Si vous recevez ce message par erreur, merci de le detruire et d'en avertir immediatement l'expediteur. Toute utilisation de ce message non conforme a sa destination, toute diffusion ou toute publication, totale ou partielle, est interdite, sauf autorisation expresse. L'internet ne permettant pas d'assurer l'integrite de ce message, BNP PARIBAS (et ses filiales) decline(nt) toute responsabilite au titre de ce message, dans l'hypothese ou il aurait ete modifie.

2 1

Please help me understand boost:lambda
by TP Diffenbach 21 Jul '04

21 Jul '04

I'm having some difficulties figuring out how to use boost::bind and boost::lambda Here's what I've trying to do: use transform to transform the values in one container to another, looking up the new value as a function of the old. What I'm trying to do is conceptually simple: call std::transform with a predicate that takes the original value, does a std::find_if on that value in another "container" using a bound std::greater< int > predicate, converts the returned iterator to an integral distance, and inserts that integral distance in the container that is the destination of the transform. Doing this using a hand-coded functor is easy enough, but I'm not able to figure out how to do it using boost::lambda. If I understand lambda, this should make each element of c equal to four times the corresponding element of o, and indeed this compiles as works as expected. std::transform( o.begin(), o.end(), std::back_inserter( c ), _1 = _1 * 4 ) ; This bit of code will look up a value, the index of the first element in partition with a value greater than v (or 3 if v is greater than all values in partition: int partition[] = { 10, 20, 30 } ; offset = std::find_if( partition, partition + 3, boost::bind( std::greater< int >(), _1, v ) ) - partition ; This code wraps the lookup and the subtraction that turns the returned pointer into an offset: template< template< typename > class Pred, typename It, typename T > int find_region_offset( It b, It e, T val ) { return std::find_if( b, e, std::bind2nd( Pred< T >(), val ) ) - b ; } and this code uses the wrapper, along with the transform: std::transform( o.begin(), o.end(), std::back_inserter( c ), boost::bind( find_region_offset< std::greater, int*, int>, partition, partition + 3, _1 ) ) ; So far, so good. What I don't know how to do is to dispense with the wrapper. As close as I can come is to use this class: struct identityPred { int operator()( int i ) { return i ; } } ; to do this: std::transform( o.begin(), o.end(), std::back_inserter( c ), boost::bind( std::less< int* >(), // to subtract the returned pointer from partition boost::bind( std::find_if< int*, identityPred >, partition, partition + 3, identityPred() ), partition) ) ; This compiles, but I don't want identityPred, I want boost::bind( std::greater< int >(), _1, _1X ) where _1 is the value in the partition array and _1X is the value read from container o. Ideally I'd like to do this using boost::lambda, which I think would look something like: std::transform( o.begin(), o.end(), std::back_inserter( c ), _1 = find_if(partition, partition + 3, _1 > var( _1 )) - partition ) ; where the first and last "_1"s are transform's (containers o and c's) values, and middle one is partition's values. Again, what I'm trying to do is conceptually simple: call transform with a predicate that takes the original value, does a find_if on that value in another "container" using a bound std::greater< int > predicate, converts the returned iterator to an integral distance, and inserts that integral distance in the container that is the destination of the transform. So if someone could point out to me what I'm doing wrong, or point me to more examples of using boost::lambda than are contained in the boost::lambda documentation, or could just tell me that what I'm trying to do isn't possible (and why it's not possible) I'd very much appreciate it. Thanks. PS And a technical trouble: if I include both boost::bind and boost::lambda, and I am using namespace boost::lambda to save qualifying each _1, I get a type redefinition for _1, with one definition in boost::bind, when using gcc under cygwin: b.cpp:49: error: use of `_1' is ambiguous /usr/local/include/boost/lambda/core.hpp:74: error: first declared as `const boost::lambda::placeholder1_type&boost::lambda::<unnamed>::_1' here /usr/local/include/boost/bind/placeholders.hpp:55: error: also declared as ` boost::arg<1> <unnamed>::_1' here b.cpp:57: error: use of `_1' is ambiguous /usr/local/include/boost/lambda/core.hpp:74: error: first declared as `const boost::lambda::placeholder1_type&boost::lambda::<unnamed>::_1' here /usr/local/include/boost/bind/placeholders.hpp:55: error: also declared as ` boost::arg<1> <unnamed>::_1' here Should this be happening?

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date-time
by Jonathan Oulds 21 Jul '04

21 Jul '04

Could anyone explain to me why there is not a default constructor for boost::gregorian::date_time and boost::posix_time::ptime. I implemented a simple constructor where both classes are created as 'not_a_date_time'. The only problem I have had is compiling my code on other peoples machines that do not have my modification to the date_time library. jonathan

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RE: [Boost-users] database lib
by Ajit Jadhav 21 Jul '04

21 Jul '04

Regarding DTL, see http://lists.boost.org/MailArchives/boost/msg13153.php. Not sure where it stands now. > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Chris > Sent: Wednesday, July 21, 2004 11:13 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] database lib > > > Hi all, > > I am wondering if there are any plans to include a database > library, for example for ODBC in the boost library. > > Please bear in mind that I am new to the boost libraries and > find them really cool. > > But like the socket library I found it because of an old > post, so that is why I am asking about the database library. > > Also I found this library really interesting and am using it > in a couple of small spike solutions: > http://dtemplatelib.sourceforge.net/index.htm > (Any comments > on the library are welcome) > > Thanks, > Chris > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/bo> ost-users >

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Testing boost installation
by Tom Puverle 21 Jul '04

21 Jul '04

In our environment it is a requirement that all libraries that are about to be deployed are tested. I would like to know if there is a way in which I can run the regression tests against the installed version of the boost headers and libraries, so that I can check they have been built and installed correctly. Thanks. _________________________________________________________________ Want to block unwanted pop-ups? Download the free MSN Toolbar now! http://toolbar.msn.co.uk/

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boost equivalent to sgi hash_map?
by Stephen torri 21 Jul '04

21 Jul '04

Is there a boost equivalent to SGI hash_map? I am looking for a data structure that taking the key finds the data in one step O(1). Stephen

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FW: boost::filesystem on WIN32: Problem passing pointer of native to path
by Christian Hoffmann 21 Jul '04

21 Jul '04

Hello... We have problems here passing the boost::filesystem::native function as a checker on WIN32 platform, eg. like this ... boost::filesystem::path path ("d:\hello\hello", boost::filesystem::native); ... When we take the address of the function "boost::filesystem::native(...)" in dll A and the pass it to boost filesystem dll, the various comparisons with "native" inside path_posix_windows.cpp:m_path_append ( const std::string & src, name_check checker ) fail, and and the code throws an invalid name exception. (e.g. line 242: if ( (checker == no_check || checker == native) && src.size() >= 2 ) fails as checker != native) The microsoft compiler takes the address into an internal function table, instead of the adress of the "real" boost::filesystem::native () function, so the comparison can never be true. Anybody got an idea what to do? PS: Getting the address of the native function like this works: path ("d:\hello\hell", reinterpret_cast<boost::filesystem::path::name_check> (GetProcAddress (GetModuleHandle("boost_filesystem-vc71-mt-gd-1_31"), "?native@filesystem@boost@@YA_NABV?$basic_string@DU?$char_traits@D@std@@ V?$allocator@D@2@@std@@@Z"))); But is not really an option... -- Christian Hoffmann This message, including any attachments, is intended only for the person(s) to whom it is addressed. If you received it in error, please let us know and delete the message from your system. This message may be confidential and may fall under the duty of non-disclosure. Any use by others than the intended addressee is prohibited. Trema shall not be liable for any damage related to the electronic transmission of this message, such as failure or delay of its delivery, interception or manipulation by third parties, or transmission of viruses or other malicious code.

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