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Problem with boost::any.
by Luc Bergeron 11 Oct '02

11 Oct '02

Greets, I'm trying to use the boost::any component but i'm having problem with it !!! I'm using it because I need a way to store parameters of different type. That real fine but I can't retrieve the value from the boost::any. This is what i've tried : std::string GetStringFromAny(const boost::any& val) const { std::string strVal; try { strVal = boost::any_cast<std::string>(val); } catch(boost::bad_any_cast &err) { std::cerr << err.what() << std::endl; return ""; } return strVal; } But I always have a bad_any_cast exception. From the documentation, at leats what I understand of it, "If passed a value or reference, it returns a copy of the value content if successful". Can someone point me in the right direction as to how can I extract the value within a boost::any type, I think i'm lost !!! :) Thanks in advance for any help. Luc.

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Possible bug in boost_1_28
by Christopher Henrich 11 Oct '02

11 Oct '02

This bug comes up when I try to include <boost/array.hpp> in certain CodeWarrior projects. (CodeWarrior 8.0, running under Mac OS 10.1.5 on G3 "beige tower") If I initialize the project with stationery "C++ Console Mach-O", and I change HelloWorld.cp to include <boost/array.hpp>, then I get this error message: Error: undefined identifier 'ptrdiff_t' suffix.hpp line 204 included from config.hpp: 57 array.hpp:27 HelloWorld.cp: 10 If I initialize with PowerPlant stationery, I do not have this problem. Chris Henrich

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BOOST regex problem using Libarys with Borland Builder 4
by Alastair 11 Oct '02

11 Oct '02

Hi I have just found out about the boost library's so I am new to them. I am trying to use the regex within a VCL Borland Builder 4. I have followed the installation. and tried a given example. I found that the example works well for a console program but for a windows program it seems to crash with the message. EAccessViolation with message ŽAccess violation at address 0040987B. Read address 00000032. I have compiled both within the Borland IDE and I believe that I don't have to do anything and that the IDE and Library will automatically configure itself. What am I doing wrong? Thanks in advance Alastair

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Thread Lib Build errors in xtime.cpp
by Glenn Thorne 10 Oct '02

10 Oct '02

I'm getting the following errors when trying to build Boost using the Intel C++ v6.0 compiler. The build completes as expected with msvc. Is there a problem with boost::uint64_t in this configuration or am I missing a setting somewhere? Any help will be appreciated. Thanks! Glenn ******** C:\boost_1_28_0>set INTELC="C:\Program Files\Intel\Compiler60\IA32" C:\boost_1_28_0>bjam "-sTOOLS=intel-win32" ...found 330 targets... ...updating 12 targets... vc-C++ libs\thread\build\bin\libboost_thread.lib\intel-win32\debug\runtime-link- static\threading-multi\xtime.obj xtime.cpp libs\thread\build\../src\xtime.cpp(80): error: namespace "boost" has no member " uint64_t" const boost::uint64_t TIMESPEC_TO_FILETIME_OFFSET = ((boost::uint64_t) 27111902UL << 32) + (boost::uint64_t)3577643008UL; ^ libs\thread\build\../src\xtime.cpp(80): error: namespace "boost" has no member " uint64_t" const boost::uint64_t TIMESPEC_TO_FILETIME_OFFSET = ((boost::uint64_t) 27111902UL << 32) + (boost::uint64_t)3577643008UL; ^ libs\thread\build\../src\xtime.cpp(80): error: expected a ")" const boost::uint64_t TIMESPEC_TO_FILETIME_OFFSET = ((boost::uint64_t) 27111902UL << 32) + (boost::uint64_t)3577643008UL; ^ libs\thread\build\../src\xtime.cpp(80): error: namespace "boost" has no member " uint64_t" const boost::uint64_t TIMESPEC_TO_FILETIME_OFFSET = ((boost::uint64_t) 27111902UL << 32) + (boost::uint64_t)3577643008UL; ^ libs\thread\build\../src\xtime.cpp(80): error: expected a ";" const boost::uint64_t TIMESPEC_TO_FILETIME_OFFSET = ((boost::uint64_t) 27111902UL << 32) + (boost::uint64_t)3577643008UL; ^ compilation aborted for libs\thread\build\../src\xtime.cpp (code 2) "C:\Program Files\Intel\Compiler60\IA32/bin/icl" /Zm400 -nologo -GX -c /Z 7 /Od /Ob0 /GX /GR MTd -I"libs\thread\build" -I"C:\boost_1_28_0" -I"C:\PROGR A~1\MICROS~3\VC98\include" -I"../include" -Fo"libs\thread\build\bin\libboo st_t hread.lib\intel-win32\debug\runtime-link-static\threading-multi\xtime.obj" -Tp" libs\thread\build\../src\xtime.cpp" ...failed vc-C++ libs\thread\build\bin\libboost_thread.lib\intel-win32\debug\run time-link-static\threading-multi\xtime.obj... ...skipped <libs!thread!build\libboost_thread.lib\intel-win32\debug\runtime-link -static\threading-multi>libboost_thread.CMD for lack of <libs!thread!build\libbo ost_thread.lib\intel-win32\debug\runtime-link-static\threading-multi>xtime.o bj.. . ...skipped <libs!thread!build\libboost_thread.lib\intel-win32\debug\runtime-link -static\threading-multi>libboost_thread.lib for lack of <libs!thread!build\libbo ost_thread.lib\intel-win32\debug\runtime-link-static\threading-multi>xtime.o bj.. . ********

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CVS fails to build
by Björn Lindberg 10 Oct '02

10 Oct '02

Boost CVS isn't working for me right now. When I try to build programs against it I get /home/compbio/d95-bli/include/boost/preprocessor/cat.hpp:18:49: boost/preprocessor/config/config.hpp: Filen eller katalogen finns inte /home/compbio/d95-bli/include/boost/preprocessor/cat.hpp:22:28: missing binary operator before '(' /home/compbio/d95-bli/include/boost/preprocessor/cat.hpp:29:28: missing binary operator before '(' ... Is it (a) a bug, or (b) me doing something wrong, or (c) something else? I am running g++-3.2 on GNU/Linux. Björn

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boost vs. The Lawyers (non-technical)
by Brian Neal 10 Oct '02

10 Oct '02

I hope this is appropriate for this mailing list... I am a software engineer and our development team loves boost. However, I can already see a coming battle with our company lawyers trying to convince them to let us use boost in our software. We informally talked with one of our software quality engineers. He said their major concern would be assuring that we had permission to use the boost software. In other words, how would we know that the boost developers had permission to release their libraries so that anyone could use it? He also thought we would need something in writing to this effect. Since their isn't any official boost organization, I am getting scared already. I am not a lawyer, nor do I play one on TV, but I would like to hear from any boost developer or user who has experiences in dealing with this nonsense. 1) How did you get your company lawyers off your backs and let you use boost? 2) Should there be (is there?) a central boost license that all boost libraries have that we can point our lawyers at, instead of going to each and every boost developer to get permission to use his/her library? 3) What has been your experience in this situation? Its ironic that something as wonderful as boost, which gives us so much productivity (and that savings is passed along to our customers) could be considered so dangerous by our lawyers. Again, if this is not appropriate or has been rehashed to death I apologize. If that is the case, please email me off list. I'll collect the responses and give them to anyone who is interested. Thanks, Brian Neal

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tuple vs SGI/MIPSPro
by Kevin Wheatley 10 Oct '02

10 Oct '02

Hi, I'm starting to get to grips with boost and in particular on the SGI platform. I was trying to use the boost::tuples and found that with the SGI compiler v7.3.1.3m I was getting the following error CC -LANG:std -I/images/src/boost/from_cvs/boost -I/images/src/boost/from_cvs/boost/boost/compatibility/cpp_c_headers/ -o tupple tupple.cpp cc-1239 CC: ERROR File = /images/src/boost/from_cvs/boost/boost/tuple/tuple_io.hpp, Line = 113 "close" is ambiguous. case close : c = i.widen(')'); break; ^ A template was detected during header processing. instantiation of "char boost::tuples::detail::format_info::get_manipulator(std:: basic_ios<char, std::char_traits<char>> &, boost::tuples::detail::format_info::manipulator_type)" at line 437 instantiation of "std::basic_istream<char, std::char_traits<char>> &boost::tuples::detail::extract_and_check_delimiter(std:: basic_istream<char, std::char_traits<char>> &, boost::tuples::detail::format_info::manipulator_type)" at line 511 instantiation of "std::basic_istream<char, std::char_traits<char>> &boost::tuples::operator>>(std::basic_istream<char, std::char_traits<char>> &, boost::tuples::cons<double, boost::tuples::detail::map_tuple_to_cons<double, double, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>::type> &)" at line 630 of "/usr/include/CC/stl_iterator.h" instantiation of "void std::istream_iterator<density, char, std::char_traits<char>, ptrdiff_t>::_M_read()" at line 604 of "/usr/include/CC/stl_iterator.h" instantiation of "std::istream_iterator<density, char, std::char_traits<char>, ptrdiff_t>::istream_iterator(std::istream_iterator<densit y, char, std::char_traits<char>, ptrdiff_t>::istream_type &)" at line 19 of "tupple.cpp" I'm working with the code from CVS because it compiled better on the SGI, I looked at the code, and basically I think it's getting confused due to my test program including a "using namespace std;" so I modified the tuple_io.hpp to specifically mention detail::format_info::close rather than the bare close and then my example works (I also made explicit the other cases of the switch statement). Is there a more recomended way of doing this? Almost everywhere else in that file the full specification of the enum is given. My code is something like: #include <vector> #include <iostream> #include <algorithm> #include <numeric> #include <iterator> #include "boost/tuple/tuple.hpp" #include "boost/tuple/tuple_comparison.hpp" #include "boost/tuple/tuple_io.hpp" using namespace std; using namespace boost::tuples; typedef tuple<double, double, double> density; int main() { vector<density> v; istream_iterator<density> in(cin); istream_iterator<density> eos; ostream_iterator<density> out(cout); density total; copy(in, eos, back_inserter(v)); copy(v.begin(), v.end(), out); cout << endl; return 0; } Thanks Kevin -- | Kevin Wheatley | These are the opinions of | | Senior Do-er of Technical Things | nobody and are not shared | | Cinesite (Europe) Ltd | by my employers |

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Building regex on AIX w VisualAge
by Tim Daplyn 10 Oct '02

10 Oct '02

Can anyone assist me with this? I've tried every compiler option I can think of combined with disabling BOOST support for a whole bunch of stuff and I still can't get this library to build on AIX. There are just too many compile errors, and I was really hoping I wouldn't have to go modifying the source.

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How to Create Calculated Internal Properties?
by Phillip Ratzloff 10 Oct '02

10 Oct '02

I wish to create an internal calculated property that is derived from existing properties in a vertex or edge. Id also like to be able to access it like any other internal property. For instance, I want a vertex property called weight_sum that would sum the weights for all the out edges and return the answer. I want to be able to use a statement "get(vertex_weight_sum,G,v)" to get the value. Later on, I may decide that I want to cache the value on the vertex (like a normal property) and existing code should work without change. I have been unable to figure out any template class specializations to do this. Additionally, if I try to define the property using the property<> template in the graph declaration it reserves storage for the property, which is undesired. Am I missing something? Is there a way to define a calculated internal property that doesnt reserve storage?

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using weak_ptr and shared_ptr for singleton
by Stephan Born 09 Oct '02

09 Oct '02

Hello! I do some experiments on shared_ptr and weak_ptr. So I tried to use them for a singleton-class, which does not need an explicit singleton::release_instance method. The singleton-instance will be destroyed everytime the last external shared_ptr holding the instance goes out of scope. Is this a valid usage for weak_ptr? Are there any traps I do not see using these smart_ptrs in this context? The drawback of using shared_ptr with singleton is the need for a public destructor. But this is dangerous....it is possible to write singleton::singleton_ptr first_ptr = singleton::instance(); delete first_ptr.get(); Declaring the destructor as private is only possible when defining boost::checked_delete as friend of the singleton-class. ( there is a thread on comp.lang.c++.moderated with the topic 'specialization of function template as friend with MSVC6SP5 not possible' which deals with this problem of friendship... ) But then it is still possible to write the following code singleton::singleton_ptr first_ptr = singleton::instance(); boost:checked_delete( first_ptr.get() ); OK, it's very unlikely to do it by chance, but it is possible. Is there a way to allow destruction of the instance only to shared_ptr? <code> #include <boost/shared_ptr.hpp> #include <boost/weak_ptr.hpp> #include <boost/utility.hpp> class singleton : boost::noncopyable { public: typedef boost::shared_ptr< singleton > singleton_ptr; static singleton_ptr instance() { singleton_ptr tmp; if( s_instance.expired() ) { tmp.reset( new singleton ); s_instance = tmp; } else { tmp = boost::make_shared( s_instance ); } return tmp; } void foo() { // do something i++; } // like to make it private in order to prohibit delete on it, // but boost::shared_ptr<> can't handle it....so sad :( ~singleton(){}; private: typedef boost::weak_ptr< singleton > internal_singleton_ptr; singleton(){}; int i; static internal_singleton_ptr s_instance; }; singleton::internal_singleton_ptr singleton::s_instance; int main() { { singleton::singleton_ptr first_ptr = singleton::instance(); { singleton::singleton_ptr second_ptr = singleton::instance(); second_ptr->foo(); } first_ptr->foo(); } singleton::singleton_ptr another_ptr = singleton::instance(); another_ptr->foo(); return 0; } </code> Regards, Stephan -- --------------------------------------------------------------- Dipl.-Inf. (FH) Stephan Born | beusen Solutions GmbH fon: +49 30 549932-0 | Landsberger Allee 366 fax: +49 30 549932-21 | 12681 Berlin mailto:stephan.born@beusen.de | Germany --------------------------------------------------------------- PGP-Key verfügbar | PGP-Key available ---------------------------------------------------------------

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