February 2008 - Boost-users - lists.preview.boost.org

including boost/thread.hpp gives compile error under VS7 in utility\base_from_member.hpp
by jason72＠internode.on.net 06 Mar '08

06 Mar '08

Using Visual Studio 2003 (VS7) and boost 1.34.1, I have simply declared the following code and I get the resulting errors: Code: #pragma once #include <deque> #include <boost/thread.hpp> using namespace std; <SNIP> Compiler output: cl /c /W3 /G6 /GF /Gy /nologo /DNDEBUG /DWIN32 /D_WIN32 /D_WIN32_WINNT=0x0500 /DWINVER=0x0500 /D_WIN32_IE=0x060 0 /D_AFXDLL /D_WTL_NO_CSTRING /D_WTL_NO_WTYPES /D_WTL_NO_UNION_CLASSES -D_X86_=1 /Ox /Z7 /I\src\r870\develop\work\pcd m\std\include /DNT /Dpcdm /DDBREL=870 /D_WIN32_DCOM -GX /DREGISTER_PROXY_DLL /GR /EHsc /MD /Fohtsserver.obj htsserver.cpp.cpp htsserver.cpp.cpp c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(78) : see reference to class template instantiation 'boost::base_from_member<MemberType,UniqueID>' being compiled c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(78) : error C2143: syntax error : missing ';' before '}' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(78) : error C2238: unexpected token(s) preceding ';' c:\apps\VS .NET 2003\Vc7\include\ostream(604) : fatal error C1903: unable to recover from previous error(s); stopping compilation NMAKE : fatal error U1077: 'cl' : return code '0x2' Stop. Note that I havent declared or used any of the threading or mutex objects yet. It is not possible to upgrade compiler version for this project. Regards, Jason

2 1

[iostream] Overloaded bitshift operators
by Robert Dailey 05 Mar '08

05 Mar '08

Does the Boost.Iostreams library have overloaded bitshift operators? That way I could do: boost::iostreams::stream<myclass> theOutputStream; theOutputStream << MyData;

2 4

[iostreams] Inconsistency b/w docs and code of stream()
by Nitay Joffe 05 Mar '08

05 Mar '08

>> > Nitay Joffe wrote: >> > Hey guys, >> > >> > I'm working with the boost::iostreams library to create a stream object >> > from >> > a Device class I've implemented. I'm trying to call the constructor that >> > allows setting of the buffer size and it is failing to compile on 64 bit. >> > >> > I used the documenation at >> > http://www.boost.org/libs/iostreams/doc/guide/generic_streams.html#stream >> > >> > The docs say the constructor is of the form: >> > >> > stream(const T& t, >> > std::streamsize buffer_size = default_value, >> > std::streamsize pback_size = default_value); >> > >> > >> > My code to create the stream looks like: >> > >> > MyDevice myDevice(...) >> > MyStream(myDevice, (std::streamsize)500); >> > >> > >> > On a 32 bit machine this works fine, but on a 64 bit one it does not >> > compile. The parameters I'm passing in are not matching up with a > > Would you please post the compiler errors? > >> > Thanks, >> > -n Sure, here is sample code that causes the error: #include <iosfwd> #include <boost/iostreams/categories.hpp> #include <boost/iostreams/stream.hpp> struct MyDevice { typedef char char_type; typedef boost::iostreams::source_tag category; std::streamsize read(char *s, std::streamsize n) { return n; } }; typedef boost::iostreams::stream<MyDevice> MyStream; int main() { MyDevice d; MyStream s(d, (std::streamsize)500); return 0; } And here are the compile errors: g++ a.cc k/usr/include/boost/iostreams/stream.hpp: In constructor 'boost::iostreams::stream<Device, Tr, Alloc>::stream(U100&, const U0&) [with U100 = MyDevice, U0 = std::streamsize, Device = MyDevice, Tr = std::char_traits<char>, Alloc = std::allocator<char>]': a.cc:18: instantiated from here /usr/include/boost/iostreams/stream.hpp:110: error: no matching function for call to 'MyDevice::MyDevice(MyDevice&, const long int&)' a.cc:5: note: candidates are: MyDevice::MyDevice() a.cc:5: note: MyDevice::MyDevice(const MyDevice&) make: *** [all] Error 1 If I change the (std::streamsize) to (int) it compiles. Cheers, -n

2 1

[foreach][range] How would BOOST_REVERSE_FOREACH be implemented?
by Pete Bartlett 05 Mar '08

05 Mar '08

Boost.Foreach is such a great piece of kit that once you start using it you just can't stop. Indeed I like working directly with values rather than iterators so much that is feels normal for me to write something like BOOST_FOREACH( value_type x , make_iterator_range( rbegin( seq ) , rend( seq ) ) whenever I wish to reverse iterate over a sequence. My co-workers are not big fans of typing though, so they want a REVERSE_FOREACH. At first naïve glance it looks easy to implement in terms of the original FOREACH: template<typename C> inline iterator_range</* something */> make_reverse_iterator_range(C& c) { return make_iterator_range( rbegin(c) , rend(c) ); } #define REVERSE_FOREACH( x , container ) BOOST_FOREACH( x , make_reverse_iterator_range( container ) ) This works fine when container is an lvalue. But then co-workers, used to the wonders of the original FOREACH, inevitably start to use the new macro with rvalues and get a crash due to dangling references (- the iterator_range's members point to departed quantities.....) and if you could somehow work around that, there is the issue hidden inside the "/* something */" that you have to cope with fact that MSVC has no proper const rvalue detection. Finally the #define MACRO(x,y) ANOTHER_MACRO( f(x) , g(y) ) style is not recommended because they are brittle in the face of x and/or y themselves being macros. ... but all these issues are exactly the ones that BOOST_FOREACH itself solves! Thus surely it is technically possible to write a REVERSE_FOREACH that works with rvalues as well as lvalues, e.g. by essentially copying and pasting the FOREACH implementation and replacing "begin" and "end" by "rbegin" and "rend" in the vital places. However one feels there may be a better way... has anyone had a go at creating a "fully-functional" REVERSE_FOREACH and could offer me any advice? If indeed the task is fairly intricate and requires re-use of foreach internals, would the library author consider including something in the library itself? Many thanks for reading, Pete Bartlett

4 6

Ann: Floating Point Utilities Review starts today
by John Maddock 04 Mar '08

04 Mar '08

The review of Johan Rade's floating point utilities starts today. Code and docs can be downloaded from : http://www.boost-consulting.com/vault/index.php?action=downloadfile&filenam… The library consists of three parts: 1) Floating point classification routines: these are optimised implementations of the C99 and C++ TR1 functions fpclassify, isinf, isnan, isnormal and isfinite. From Boost-1.35 onwards these are already a part of Boost.Math (see http://svn.boost.org/svn/boost/trunk/libs/math/doc/sf_and_dist/html/math_to…) so if accepted the two implementations will get merged. The review here should focus on the implementation used, and testing on whatever platforms you have available - in particular are there any circumstances (compiler optimisation settings etc) where this implementation breaks? 2) Sign manipulation functions: implementations of the C99 and C++ TR1 functions copysign and signbit, plus the changesign function. Two of these (signbit and copysign) are currently undocumented members of Boost.Math, and again the two implementations will get merged if this library is accepted. Again the main focus of the review here is the implementation, and testing thereof especially in the presence of compiler optimisations. 3) C++ locale facets: these will read and write non-finite numbers in a portable and round-trippable way: that is not otherwise possible with current C++ std library implementations. These are particularly useful for number-serialisation for example. Since the design is already specified by the C++ standard for these facets, your review here should focus on implementation, testing, documentation, and perhaps where in Boost these should best be placed if accepted. These look to be a useful collection of utilities, so I'll look forward to your reviews, Regards, John Maddock, Floating Point Utilities Review Manager.

9 34

Boost file system idiocy
by Patrick Loney 02 Mar '08

02 Mar '08

Can't find how to seek to eof, currently using: fs.seekp( (std::streamoff)boost::filesystem::file_size( SKDO::ArchiveFilePath( keyname ) ) ); please help ****************************************************************************** "This message and any attachments are solely for the intended recipient and may contain confidential and privileged information. If you are not the intended recipient, any disclosure, copying, use, or distribution of the information included in this message and any attachments is prohibited. If you have received this communication in error, please notify us by reply e-mail and immediately and permanently delete this message and any attachments. Thank you." Interactive Transaction Solutions Ltd (2473364 England) Registered Office: Systems House, Station Approach Emsworth PO10 7PW ********************************************************************** Ce message �lectronique contient des informations confidentielles � l'usage unique des destinataires indiqu�s, personnes physiques ou morales. Si vous n'�tes pas le destinataire voulu, toute divulgation, copie, ou diffusion ou toute autre utilisation de ces informations, est interdite. Si vous avez re�u ce message �lectronique par erreur, nous vous remercions d'en avertir son exp�diteur imm�diatement par email et de d�truire ce message ainsi que les �l�ments attach�s. Interactive transaction Solutions SAS- France (RCS Pontoise : 489 397 877) Si�ge social : Parc Saint Christophe, 10, Avenue de l�Entreprise 95865 Cergy-Pontoise Cedex ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________

2 1

Bind + Function + Arguments
by QbProg 01 Mar '08

01 Mar '08

Hello there, I've started using boost function and bind features , and I'd like to find a way to do the following. You can take it as suggestion, if it is not implemented :) I would like to use the bind function on object members in the same way indipendently of the number of arguments. For example: function <void (int , int ) > FunctionOne; function < bool (int ) > FunctionTwo; class Implementor { public: void ImplOne ( int , int ); bool ImplTwo ( int ); }; void test () { Implementor i; FunctionOne = bind ( &Implementor::ImplOne , &i , _1 , _ 2); FunctionTwo = bind (&Implemenetor::ImplTwo, &i , _1); /* I Would be nice to do something like this, with parameter "guessing" */ // FunctionOne = GenericBind ( &Implementor::ImplOne ,&i); // FunctionTwo = GenericBind ( &Implementor::ImplTwo, &i); /* This will greatly remove verbosity! */ /* Actually I do */ #define Bind0(A,B) bind(A,B) #define Bind1(A,B) bind(A,B,_1) #define Bind2(A,B) bind(A,B,_1,_2) ...... FunctionOne = Bind2 ( &Implementor::ImplOne , &i ); FunctionTwo = Bind1 ( &Implementor::ImplTwo , &i); } It would be usefoul to make library callbacks more usable, insteat of writing a long list of arguments each time. It is possible with current implementation? I ask you for any suggestion, Thank you QbProg

2 3

static assert
by Hicham Mouline 01 Mar '08

01 Mar '08

hi, I would like to avoid template instantiations with ContractType whose static functions st1 and st2 return an enum... template <typename ContractType> class C { BOOST_STATIC_ASSERT( !(ContractType::st1()==A && ContractType::st2()==P) ); ... }; Is there a way to make this work?

4 4

BGL: Can bundled properties not be a struct or class name?
by Jean-Olivier Racine 29 Feb '08

29 Feb '08

Good day, I have a graph with bundled properties attached to both the vertices and edges. typedef long int ASElementID; enum ASRelationships { NoRelationship, IsContaining, IsBeside, IsAbove, IsCommentedBy, IsMadeOf }; typedef boost::adjacency_list<boost::vecS, boost::listS, boost::bidirectionalS, ASElementID, ASRelationships> Graph; When using the write_graphviz and writing my property writer, I get the error_property_not_found error. Reading post 18294 (http://thread.gmane.org/gmane.comp.lib.boost.user/18294) I see what I should probably do. My problem is that I cannot give the address of ASElementID since it is an int. Is it a limitation? Do I *have* to use a struct for it to work? Something like: struct IDType {int ID}; Thanks and have a nice weekend! Jean-Olivier

1 0

[boost test] question on exception testing
by Ovanes Markarian 29 Feb '08

29 Feb '08

Hello *, I have a question regarding the tools BOOST_<level>_THROW: Why is it required to specify the exception being thrown? What if I don't know which exception is thrown, but I know that it should be thrown? My use case is: I have a worker class which executes some functionality. I know that the functionality will throw, but I would like to test that my class will remain in the consistent state after the exception was thrown? With BOOST_<level>_THROW(class_inst.execute()) I could spare the try{}catch(...){} block and make other test assertions, but unfortunately it is not possible, due to lacking of this utility. I would propose a throw guard into the lib, which does not produce any assertion, but swallows an exception. My intention is: I have to develop inside of a huge framework. The functionality I am trying to execute will only work on a target hardware. Since I am inside a debugger and not going to test the the executed functionality itself, but check the state of my class I think such a tool might help. With Kind Regards, Ovanes

2 4

Re: [Boost-users] A request for help using the Boost Unit Test Library
by Tim Allison 29 Feb '08

29 Feb '08

> > Message: 2 > Date: Thu, 28 Feb 2008 18:44:34 +0000 (UTC) > From: Gennadiy Rozental <rogeeff(a)gmail.com> > Subject: Re: [Boost-users] A request for help using the Boost Unit > Test Library > To: boost-users(a)lists.boost.org > Message-ID: <loom.20080228T184232-270(a)post.gmane.org> > Content-Type: text/plain; charset=us-ascii > > Tim Allison <tallison <at> meicompany.com> writes: >>> What compiler are u using? Can you post compilation command? These errors > may >>> only mean that you doing something funny during compilation and compiler > do >>> not see BOOST_AUTO_TEST_CASE macro. >> I am using Gnu compiler 4.1.3-29. I have reduced the number of >> switches, so that the actual line used to build is: >> g++ -g -I../lib -I/usr/X11R6/include -I../../../source/ecs/shared >> -DOS_IS_LINUX -c FuserTests.cc > > Where is boost include? Can you generate preprocessed code? Do you see boost > test code? what do u see in place of BOOST_AUTO_TEST_CASE( test1 )? > > Gennadiy > I ran the -E option on the Gnu compiler. Here is what I hope is the relevant output (at the end of the 38K resulting file!): inline test_case* make_test_case( callback0<> const& test_func, const_string tc_name ) { return new test_case( ut_detail::normalize_test_case_name( tc_name ), test_func ); } template<typename UserTestCase> inline test_case* make_test_case( void (UserTestCase::*test_method )(), const_string tc_name, boost::shared_ptr<UserTestCase> const& user_test_case ) { return new test_case( ut_detail::normalize_test_case_name( tc_name ), ut_detail::user_tc_method_invoker<UserTestCase>( user_test_case, test_method ) ); } } } # 1 "/usr/include/boost/test/detail/enable_warnings.hpp" 1 3 4 # 246 "/usr/include/boost/test/unit_test_suite.hpp" 2 3 4 # 20 "/usr/include/boost/test/unit_test.hpp" 2 3 4 # 5 "FuserTests.cc" 2 BOOST_AUTO_TEST_CASE( test1 ) { boost::test_tools::tt_detail::check_impl( (2 == 1), boost::wrap_stringstream().ref() << boost::unit_test::literal_string( "2 == 1", sizeof( "2 == 1" ) - 1 ), boost::unit_test::literal_string( "FuserTests.cc", sizeof( "FuserTests.cc" ) - 1 ), (std::size_t)12, boost::test_tools::tt_detail::CHECK, boost::test_tools::tt_detail::CHECK_PRED, 0 ); } BOOST_AUTO_TEST_CASE( test2 ) { int i = 0; boost::test_tools::tt_detail::check_frwd( boost::test_tools::tt_detail::equal_impl_frwd(), boost::wrap_stringstream().ref() << "", boost::unit_test::literal_string( "FuserTests.cc", sizeof( "FuserTests.cc" ) - 1 ), (std::size_t)23, boost::test_tools::tt_detail::CHECK, boost::test_tools::tt_detail::CHECK_EQUAL , i, "i" , 2, "2" ); boost::test_tools::tt_detail::check_frwd( boost::test_tools::tt_detail::equal_impl_frwd(), boost::wrap_stringstream().ref() << "", boost::unit_test::literal_string( "FuserTests.cc", sizeof( "FuserTests.cc" ) - 1 ), (std::size_t)25, boost::test_tools::tt_detail::CHECK, boost::test_tools::tt_detail::CHECK_EQUAL , i, "i" , 0, "0" ); } Tim

2 1

Filter packages from a device e.g. network
by Hansi 29 Feb '08

29 Feb '08

Hello, I have a question regarding to filter packages from a device. What is the best way (high performance and not to much copies of the data) to filter data. e.g. I need a filter to make packages from a tcp stream. In this case I have first a field with the length of the package. Best regards Hansjörg

1 0

Using bind with function objects
by Olaf Peter 29 Feb '08

29 Feb '08

Hi, this test file doesn't compile, but why? $ LANG=en g++ bind.cpp -o bind && ./bind /usr/include/boost/bind.hpp: In member function 'R boost::_bi::list2<A1, A2>::operator()(boost::_bi::type<R>, F&, A&, long int) [with R = int, F = Foo, A = boost::_bi::list2<const char*&, const int&>, A1 = boost::arg<1> (*)(), A2 = boost::arg<2> (*)()]': /usr/include/boost/bind/bind_template.hpp:89: instantiated from 'typename boost::_bi::result_traits<R, F>::type boost::_bi::bind_t<R, F, L>::operator()(A1&, const A2&) [with A1 = const char*, A2 = int, R = int, F = Foo, L = boost::_bi::list2<boost::arg<1> (*)(), boost::arg<2> (*)()>]' bind.cpp:22: instantiated from here /usr/include/boost/bind.hpp:278: error: void value not ignored as it ought to be Thanks, Olaf

4 5

[Graph] A* with an implicit graph?
by Ian Downes 28 Feb '08

28 Feb '08

I'd like to do shortest path on an implicit graph - i.e. building it as I go, on examining a vertex I'd like to add the adjacent edges before continuing. Is this supported? If so, can someone point me in the right direction? If not, how could I do this in boost? The boost astar algorithm claims to support implicit graphs using a modified version of the boost bfs algorithm (nonconst_bfs.hpp). This modified version didn't exist in my distribution so I followed the comments in a document from the authors (link below) and removed the const requirements for the graph in breadth_first_search.hpp. The example (implicit example from pdf below, pg 12) compiles ok but seg faults when trying to add a vertex (vertex_t v = add_vertex(vert_prop(white_color), g); page 16 of pdf) in the visitor (some adds succeed first). Any ideas? http://www.cs.rpi.edu/~beevek/research/astar_bgl04.pdf thanks Ian

1 0

problem while using lapack binding
by Baris Gokce 28 Feb '08

28 Feb '08

Hello, I have downloaded binding of boost from http://news.tiker.net/dl/software/boost-bindings and copied them under the boost/numeric. In my code, I am using 'gesvd' function of lapack. There is no compilation error, but while linking following undefined reference to '_dgesvd' error occurs: ../../lib/libTemp.a(MatrixOperationsDefault.o): In function `_ZN16MatrixOperations6MO_svdERN5boost7numeric5ublas6matrixIdNS2_15basic_row_majorIjiEENS2_15unbounded_arrayIdSaIdEEEEESA_SA_SA_': /cygdrive/e/workspace3_2/Locomotion/BOUN/Locomotion/src/MatrixOperations.cc:159: undefined reference to `_dgesvd_' ../../lib/libTemp.a(MatrixOperationsDefault.o): In function `_ZN16MatrixOperations6MO_svdERN5boost7numeric5ublas6matrixIdNS2_15basic_row_majorIjiEENS2_15unbounded_arrayIdSaIdEEEEESA_SA_SA_': /cygdrive/c/boost/boost/numeric/ublas/exception.hpp:127: undefined reference to `_dgesvd_' collect2: ld returned 1 exit status make: *** [test.exe] Error 1 Do I have to compile boost with added binding files again? If yes, how? Best Regards...

1 0

Re: [Boost-users] A request for help using the Boost Unit Test Library
by Tim Allison 28 Feb '08

28 Feb '08

> ------------------------------ > > Message: 4 > Date: Thu, 28 Feb 2008 16:56:15 +0000 (UTC) > From: Gennadiy Rozental <rogeeff(a)gmail.com> > Subject: Re: [Boost-users] A request for help using the Boost Unit > Test Library > To: boost-users(a)lists.boost.org > Message-ID: <loom.20080228T165213-642(a)post.gmane.org> > Content-Type: text/plain; charset=us-ascii > > Tim Allison <tallison <at> meicompany.com> writes: > >> // each test module could contain no more then one ..... function defined >> // alternatively you could define init function yourself >> #define BOOST_TEST_MAIN >> #include <boost/test/unit_test.hpp> >> >> //___________________________________________________________________// >> >> // most frequently you implement test cases as a .... utomatic registration >> BOOST_AUTO_TEST_CASE( test1 ) > > You mean to say error is on above line, right? > >> The error messages are: >> FuserTests.cc:9: error: expected constructor, destructor, or type >> conversion before '(' token >> FuserTests.cc:18: error: expected constructor, destructor, or type >> conversion before '(' token > > What compiler are u using? Can you post compilation command? These errors may > only mean that you doing something funny during compilation and compiler do > not see BOOST_AUTO_TEST_CASE macro. I am using Gnu compiler 4.1.3-29. I have reduced the number of switches, so that the actual line used to build is: g++ -g -I../lib -I/usr/X11R6/include -I../../../source/ecs/shared -DOS_IS_LINUX -c FuserTests.cc Tim Allison > > Gennadiy > > > >

2 1

lexical_cast not throwing exception when converting negative value to UINT
by Kris Wragg 28 Feb '08

28 Feb '08

Dear subscribers, I am using lexical_cast to cast a string to an UINT, unfortunately, it is not throwing an exception if a value is negative. Example: std::wstring failString = L"-1"; UINT nTest = boost::lexical_cast<UINT>(failString); This does not throw a bad_lexical_cast exception, which it should, as -1 is not a valid unsigned integer. Perhaps I am using the wrong function, or using this one incorrectly, I've only just started using boost after moving to a new project that's not based on ancient legacy code! Regards, Kris Wragg ________________________________ This email and all attachments transmitted with it contain confidential information belonging to the sender. It is intended only for the addressee(s) stated above. Should you not be the intended recipient then any disclosure, copying, distribution or the taking of any action in reliance on the contents of this email is strictly prohibited. If you have received this transmission in error, please notify the sender immediately and permanently delete this message and destroy any copies. Internet communications cannot be guaranteed to be timely, secure, error-free or virus-free and Sender expressly does not warrant or guarantee that this e-mail is virus free. Recipient is advised to protect itself by taking the necessary steps to ensure that appropriate security measures are in place and to utilize a virus scanner before opening any attachment or down loading any information or documentation using links or other contents in this e-mail. You may opt out of receiving future communications from us by replying to this e-mail and replacing the subject line with UNSUBSCRIBE.

2 1

[mpl] Hierarchy Generation
by Scott Meyers 28 Feb '08

28 Feb '08

I have a set of types representing features code might have, e.g., typedef mpl::vector<ExceptionSafe, ThreadSafe, ReallyFast, GPLed> Features; These can occur in any combination as sets of features, e.g., tyepdef FeatureSet<ExceptionSafe> F1; typedef FeatureSet<ThreadSafe, ExceptionSafe> F2; typedef FeatureSet<ReallyFast, ExceptionSafe, GPLed> F3; There should be an implicit conversion from one FeatureSet to another if and only if we don't lose any features in the conversion. So converting from F1 to F2 or F3 is okay (since both F2 and F3 contain ExceptionSafe), but converting from F2 to F3 is not okay (because we'd lose ThreadSafe). Furthermore, a conversion that adds fewer features is preferable to one that adds more, so the conversion from F1 to F2 is better than the conversion from F1 to F3 (because the former adds only one feature while the latter adds two). I'm looking for a way to automatically generate an inheritance hierarchy that will give me the behavior I've described. For the above example, the hierarchy has four levels. The root is all the features, because any subset of features is permitted to be implicitly convertible to the set of all features. Root: FeatureSet<ExceptionSafe, ThreadSafe, ReallyFast, GPLed> The leaves are the individual features: Leaves: FeatureSet<ExceptionSafe> FeatureSet<ThreadSafe> FeatureSet<ReallyFast> FeatureSet<GPLed> The next level up is pairs of features: One level FeatureSet<ExceptionSafe, ThreadSafe> up from FeatureSet<ExceptionSafe, ReallyFast> leaves: FeatureSet<ExceptionSafe, GPLed> ... The next level up (which is one below the root) is triplets of features: One level FeatureSet<ExceptionSafe, ThreadSafe, ReallyFast> down from FeatureSet<ExceptionSafe, ThreadSafe, GPLed> root: FeatureSet<ExceptionSafe, ReallyFast, GPLed> ... In general, given a list of n features, I need a hierarchy n levels deep, with one class at the root, n classes at the leaves, and m-wise combinations of the n features at the intervening levels (where m varies from 2 to n-1). Fortunately, I don't need to worry about permutations of the ordering of the features, because I already have a way to canonically order them. (Not a great way, but it works, and that's a different problem.) Is there some way for me to use the MPL to automatically generate the hierarchy I need? Thanks, Scott

3 9

Re: [Boost-users] A request for help using the Boost Unit Test Library
by Tim Allison 28 Feb '08

28 Feb '08

I'm sorry, I completely missed your reply. Based on your comment that the new docs are for 1.34, The contents of FuserTest.cc are cut and pasted from example 1: // each test module could contain no more then one 'main' file with init function defined // alternatively you could define init function yourself #define BOOST_TEST_MAIN #include <boost/test/unit_test.hpp> //____________________________________________________________________________// // most frequently you implement test cases as a free functions with automatic registration BOOST_AUTO_TEST_CASE( test1 ) { // reports 'error in "test1": test 2 == 1 failed' BOOST_CHECK( 2 == 1 ); } //____________________________________________________________________________// // each test file may contain any number of test cases; each test case has to have unique name BOOST_AUTO_TEST_CASE( test2 ) { int i = 0; // reports 'error in "test2": check i == 2 failed [0 != 2]' BOOST_CHECK_EQUAL( i, 2 ); BOOST_CHECK_EQUAL( i, 0 ); } //____________________________________________________________________________// // EOF The error messages are: FuserTests.cc:9: error: expected constructor, destructor, or type conversion before '(' token FuserTests.cc:18: error: expected constructor, destructor, or type conversion before '(' token Tim Allison > > Today's Topics: > > 1. Re: A request for help using the Boost Unit Test Library > (Gennadiy Rozental) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 21 Feb 2008 20:05:42 +0000 (UTC) > From: Gennadiy Rozental <rogeeff(a)gmail.com> > Subject: Re: [Boost-users] A request for help using the Boost Unit > Test Library > To: boost-users(a)lists.boost.org > Message-ID: <loom.20080221T200258-326(a)post.gmane.org> > Content-Type: text/plain; charset=utf-8 > > Tim Allison <tallison <at> meicompany.com> writes: >> I am using boost 1.33.1-42 <at> 586 on Suse 10.2 (If it matters, my computer >> is a Latitude D510) and Gnu compiler 4.1.3-29 <at> 586 (as listed by Smart >> Package Manager). > > The new docs cover Boost.Test starting 1.34 > >> When I run the make file, it echos out the following line: >> g++ -Wno-deprecated -frepo -m32 -g -I../lib -I/usr/X11R6/include >> -I../../../source/ecs/shared -DOS_IS_LINUX -c FuserTests.cc >> >> FuserTests.cc is the file into which I have attempted to copy the >> examples. > > Would you care to share with us the file content? > >> The case I am most interested in running uses BOOST_AUTO_TEST_CASE( >> functionName ). This line produces the error: >> FuserTests.cc:16: error: expected constructor, destructor, or type >> conversion before ?(? token > > Obviosly Boost.Test headers are not included. > > Gennadiy > > > >

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Boost::Function: Getting a pointer to a template function
by Hans Mull 28 Feb '08

28 Feb '08

Hi! I want to use a boost::function pointer to a template function. The template type should be determinated at the time the boost::function object is initialized. Example: template<class T> inline string addNumber(T inputNumber) { return lexical_cast<string>(inputNumber + 2); } template<class numType> inline boost::function<string(numType)> getFunction(numType number) { boost::function<string(numType)> f; f = //Which code can I use here? If I call f() I want to call addNumber<numType>(number) } ---------------------- I want to use it like that: void callFunction() { boost::function<string(double)> f; f = getFunction<unsigned long>(); for(int i = 0; i < 10000;i++) { std::cout << f(rand()) << endl; } } Thanks in advance, Hans

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Looking for a boost graph algorithm
by Christian Sturz 28 Feb '08

28 Feb '08

Hi, I'm looking for an appropriate Boost Graph algorithm for the following problem: my graph (based on adjacency_list) represents the control-flow graph of a program where each vertex is a statement and the control-flow relations between the statements are modeled by edges. Now I'm looking for an algorithm that finds all vertices that can be reached from a defined statement. So, what I need is a back-traversal of the graph, from the given vertex to all predecessors and so forth. I didn't find any algorithm in the Boost Graph Library. The "strong_components" algorithm might be OK since it assumes a directed graph (as is mine) but the algorithm seems to operate in the direction of the directed edges. Obviously I need the the opposite direction. Do you know any approach/algorithm that might solve my problem? Regards, Chris -- Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger

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Problems connecting to boost repository
by Lang Stefan 28 Feb '08

28 Feb '08

Hello List, I am trying to download (parts of) the current version of boost as described in http://svn.boost.org/trac/boost/wiki/BoostSubversion. I do have a subversion client installed (version 1.4.2) as well as TortoiseSVN for windows. However, so far I have been unable to download any file(s) from the repository at http://svn.boost.org. The IT staff advised me to use a proxy server and a specific port to establish that sort of internet connection, and I found and set the appropriate options for TortoiseSVN. Afterwards, when I tried to use TortoiseSVN for downloading from the boost repository, some administrative data was transferred, but still no actual files. The error messages I got were: REPORT request failed on '/svn/boost/!svn/vcc/default' REPORT of '/svn/boost/!svn/vcc/default': 400 Bad Request (http://svn.boost.org) Can anyone tell me what's wrong, or how to access the boost svn repository properly? I would try out the command line client directly, but am not sure how to set the proxy server and port. Mit freundlichen Grüssen / Kind regards Stefan Lang

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Problems compiling programs with graphviz_read()
by Vivek Menon 28 Feb '08

28 Feb '08

Hello all,I am a newbie to Boost Graph Libraries. I am working on a Mac OSX (Intel) platform. I have compiled the libraries using the bjam executable from boost_1_34_1/tools/jam/src/bin.macosxx86/bjam This resulted in formation of libraries in bin.v2/libs/... Now I would like to compile the edge-connectivity.cpp file in boost_1_34_1/libs/graph/examples directory with the following command: g++ -I$BOOST edge-connectivity.cpp -o test1 $BOOST/bin.v2/libs/graph/build/darwin/debug/link-static/libboost_graph-d-1_34_1.a This gives me the following errors: Undefined symbols: "boost::read_graphviz(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::subgraph<boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::property<boost::vertex_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::no_property>, boost::property<boost::edge_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::property<boost::edge_index_t, int, boost::no_property> >, boost::property<boost::graph_graph_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::property<boost::graph_vertex_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::property<boost::graph_edge_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::property<boost::graph_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property> > > >, boost::listS> >&)", referenced from: _main in cctmckT6.o ld: symbol(s) not found collect2: ld returned 1 exit status Can some one explain what's going on? I have tried using -L option as well with no success: g++ -I$BOOST edge-connectivity.cpp -o test1 -L$BOOST/boost_1_34_1/bin.v2/libs/graph/build/darwin/debug/link-static/ -lboost_graph-d-1_34_1.a The examples that do not use graphviz_read() are easily compiled. I would also like to know if someone uses a jam file that lists all the dependencies for the example files. This way I can compile all the example files in the /libs/graph/examples in one shot with no linking problems. Thanks, Vivek

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[enable_if] Compiler Error with MSVC 7.1
by Christian Henning 28 Feb '08

28 Feb '08

Hi there, I'm trying to compile the following code using MSVC 7.1 but it fails. Using MSVC 8 works which leaves me with the impression that it might be a compiler bug. #include <boost/utility/enable_if.hpp> #include <boost/mpl/bool.hpp> using namespace boost; template < typename A > struct is_A : public mpl::true_ {}; template < typename B > struct is_B : public mpl::true_ {}; template< typename A > struct enable_if_A : public enable_if< typename is_A< A >::type > {}; template< typename B > struct enable_if_B : public enable_if< typename is_B< B >::type > {}; template < typename One > inline void foo( typename enable_if_A< One >::type* ptr = 0 ) {} template < typename One > inline void foo( typename enable_if_B< One >::type* ptr = 0 ) {} int _tmain(int argc, _TCHAR* argv[]) { return 0; } After a while of tinkering I got it to compile when inheriting the enable_if helper classes from enable_if<...>::type instead of from enable_if<...>. The following works: #include <boost/utility/enable_if.hpp> #include <boost/mpl/bool.hpp> using namespace boost; template < typename A > struct is_A : public mpl::true_ {}; template < typename B > struct is_B : public mpl::true_ {}; template< typename A > struct enable_if_A : public enable_if< typename is_A< A >::type >::type {}; template< typename B > struct enable_if_B : public enable_if< typename is_B< B >::type >::type {}; template < typename One > inline void foo( typename enable_if_A< One >* ptr = 0 ) {} template < typename One > inline void foo( typename enable_if_B< One >* ptr = 0 ) {} int _tmain(int argc, _TCHAR* argv[]) { return 0; } Is that a known issue with MSVC 7.1? Or is it always better to inherit from enable_if<...>::type? Regards, Christian

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The Graph Library Applied to Trees
by Charles Brockman 28 Feb '08

28 Feb '08

I'm considering using the Boost Graph Library to represent binary trees in my application. This will be a planar acyclic directed graph with an adjacency-list representation. The vertices will have properties bundled in an exterior class. A. While building the tree I need to track the depth of each branch and the greatest depth of any branch, that is, the distance from the source vertex to the farthest target vertex. For that I plan to use the distance_recorder. Is that reasonable? Are there pitfalls? Is there a better way? B. I'll need to calculate the total length of the tree by which I mean the sum of all edges. I plan to do a depth-first search and increment a counter with a visitor event point such as discover_vertex. Is that the preferred method? C. On occasion I'll have to swap vertices between two independent trees. My plan is to just swap the bundled properties of each vertex. At first I considered the remove_vertex function but the edges connected to a vertex must be removed first with clear_vertex so before I remove the vertex I'll have to record the source and the target vertices. Then I'll have to add the replacement vertex into the correct position. I can imagine that blowing up in my face. I would appreciate any guidance on this problem. -- Charles Brockman

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