March 2012 - Boost-users - lists.preview.boost.org

[preprocessor] having trouble using reentrant macros
by Rob Desbois 07 Apr '12

07 Apr '12

I'm unable to use the reentrant macros for iteration currently..I think I'm probably misunderstanding their usage, and a push in the right direction would be much appreciated. My need is to iterate through a sequence, then iterate through a sequence nested within each element. As I understand, I should be able to call (e.g.): * BOOST_PP_SEQ_FOR_EACH(OP, data, seq) to iterate through the outer sequence * then in OP(r, data, elem) call BOOST_PP_SEQ_FOR_EACH_R(r, OP2, data, elem) For me this keeps producing rubbish with a lot of non-expanded macro names embedded. I've reduced this down to a minimal example iterating over a 2-dimensional sequence; I know the final line isn't valid C++, I'm just checking preprocessing results at this stage. #include <boost/preprocessor/seq/transform.hpp> #define INNER(s, data, elem) <elem> #define MIDDLE(s, data, seq) BOOST_PP_SEQ_TRANSFORM_S(s, INNER, data, seq) #define OUTER(seqseq) BOOST_PP_SEQ_TRANSFORM( MIDDLE, _, seqseq) outer gives: OUTER( ((a) (b) (c)) ((i) (j) (k)) ((x) (y) (z)) ) Resultant output of this, with preprocessor line directives and empty lines removed, is: outer gives: ( BOOST_PP_SEQ_TAIL_I BOOST_PP_TUPLE_ELEM_3_2 BOOST_PP_SEQ_TRANSFORM_O(5, BOOST_PP_SEQ_TRANSFORM_O(4, BOOST_PP_SEQ_TRANSFORM_O(3, ( INNER , _, (nil)), a), b), c)) ( BOOST_PP_SEQ_TAIL_I BOOST_PP_TUPLE_ELEM_3_2 BOOST_PP_SEQ_TRANSFORM_O(6, BOOST_PP_SEQ_TRANSFORM_O(5, BOOST_PP_SEQ_TRANSFORM_O(4, ( INNER , _, (nil)), i), j), k)) ( BOOST_PP_SEQ_TAIL_I BOOST_PP_TUPLE_ELEM_3_2 BOOST_PP_SEQ_TRANSFORM_O(7, BOOST_PP_SEQ_TRANSFORM_O(6, BOOST_PP_SEQ_TRANSFORM_O(5, ( INNER , _, (nil)), x), y), z)) For reference, I am using the following: boost 1.46.00 g++ (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2) TIA --rob

5 8

[MSM] state transitions and exceptions
by Stephan Menzel 06 Apr '12

06 Apr '12

Everyone, I did just get around to give the MSM a first shot and I have say I am impressed at the neat design, the ease of use, "understandability", tutorial ... exceptional work. Really great and it helped me a great deal so far. So thanks a bunch for this teriffic addition to boost. That's the kind of stuff I love boost for. There is one question however that puzzles me. How can / do I prevent state transistions when a transition function throws? Most transition functions are defined like that: void so_transition(event::Cause const &e) { methodCausingAnException(); } The tutorial only mentions this at the very end of the back-end docs and this is not clear to me. I have stuff inside my transitions that may throw and the example text mentiones other valid examples (like connect() logic). So what am I supposed to do here? This? void so_transition(event::Cause const &e) { try { methodCausingAnException(); } catch (const std::exception &sex) { return ??? } } The type is void and I can't return anything that would prevent the transition. Or should I just let the exception pass? What is the correct way? Suggestions are appreciated, Stephan

7 17

udp with virtual network cards
by Gianni Ambrosio 05 Apr '12

05 Apr '12

Dear All, I implemented an UDP Multicast socket connection with boost. It works fine if I test server and client on the same PC (windows Xp or 7) but If server and client are (normally) on different PCs and at least on the client side there are virtual network cards active, the client does not receve udp data. It seems the udp connection uses one of the virtual cards and in that case it doesn't work. In fact If I deactivate all virtual cards then it starts working. Can you explain me please what's going on? Regards Gianni

3 7

Python quickstart hanging on build with bjam
by Harry Griff 04 Apr '12

04 Apr '12

Hi, I have downloaded boost_1_49_0 to my Mac with OS X 10.5.8. I then ran: In the home folder I have: using python : 3.1 : /Library/Frameworks/Python.framework/Versions/3.1/bin/python3.1 ; In user-config.jam. I then ran the following: *** *** Start Screen dump 1 *** $ ./bjam --with-python --user-config=user-config.jam Building the Boost C++ Libraries. Component configuration: - chrono : not building - date_time : not building - exception : not building - filesystem : not building - graph : not building - graph_parallel : not building - iostreams : not building - locale : not building - math : not building - mpi : not building - program_options : not building - python : building - random : not building - regex : not building - serialization : not building - signals : not building - system : not building - test : not building - thread : not building - timer : not building - wave : not building ...patience... ...patience... ...found 1599 targets... ...updating 2 targets... darwin.link.dll bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/libboost_python3.dylib Undefined symbols: "_PyFile_AsFile", referenced from: boost::python::exec_file(boost::python::str, boost::python::api::object, boost::python::api::object)in exec.o "_PyString_FromFormat", referenced from: boost::python::converter::rvalue_from_python_stage2(_object*, boost::python::converter::rvalue_from_python_stage1_data&, boost::python::converter::registration const&)in from_python.o boost::python::converter::(anonymous namespace)::throw_no_lvalue_from_python(_object*, boost::python::converter::registration const&, char const*) in from_python.o boost::python::converter::(anonymous namespace)::lvalue_result_from_python(_object*, boost::python::converter::registration const&, char const*) in from_python.o boost::python::converter::registration::to_python(void const volatile*) constin registry.o _enum_repr in enum.o _enum_repr in enum.o "_PyClass_Type", referenced from: _PyClass_Type$non_lazy_ptr in function.o "_PyNumber_Divide", referenced from: boost::python::api::operator/(boost::python::api::object const&, boost::python::api::object const&)in object_operators.o "_PyString_FromStringAndSize", referenced from: boost::python::numeric::(anonymous namespace)::load(bool) in numeric.o boost::python::detail::str_base::str_base(char const*, char const*)in str.o boost::python::detail::str_base::str_base(char const*, char const*)in str.o boost::python::detail::str_base::str_base(char const*, unsigned long)in str.o boost::python::detail::str_base::str_base(char const*, unsigned long)in str.o boost::python::converter::do_return_to_python(char)in builtin_converters.o boost::python::tuple boost::python::make_tuple<boost::python::str, boost::python::api::object, boost::python::str, boost::python::str, boost::python::str, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::python::str>(boost::python::str const&, boost::python::api::object const&, boost::python::str const&, boost::python::str const&, boost::python::str const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::python::str const&)in function_doc_signature.o boost::python::tuple boost::python::make_tuple<boost::python::api::object, boost::python::str, boost::python::str, boost::python::str, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::python::str>(boost::python::api::object const&, boost::python::str const&, boost::python::str const&, boost::python::str const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::python::str const&)in function_doc_signature.o boost::python::tuple boost::python::make_tuple<boost::python::str, boost::python::api::object, boost::python::str, boost::python::str, boost::python::str, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >(boost::python::str const&, boost::python::api::object const&, boost::python::str const&, boost::python::str const&, boost::python::str const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)in function_doc_signature.o "_PyInt_Type", referenced from: _PyInt_Type$non_lazy_ptr in enum.o "_PyString_FromString", referenced from: boost::python::detail::str_base::str_base()in str.o boost::python::detail::str_base::str_base()in str.o boost::python::detail::str_base::str_base(char const*)in str.o boost::python::detail::str_base::str_base(char const*)in str.o boost::python::converter::do_return_to_python(char const*)in builtin_converters.o "_PyInt_AsLong", referenced from: boost::python::detail::list_base::count(boost::python::api::object const&) constin list.o boost::python::detail::list_base::index(boost::python::api::object const&) constin list.o boost::python::detail::list_base::insert(boost::python::api::object const&, boost::python::api::object const&)in list.o boost::python::detail::str_base::startswith(boost::python::api::object const&, boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::isupper() constin str.o boost::python::detail::str_base::istitle() constin str.o boost::python::detail::str_base::isspace() constin str.o boost::python::detail::str_base::islower() constin str.o boost::python::detail::str_base::isdigit() constin str.o boost::python::detail::str_base::isalpha() constin str.o boost::python::detail::str_base::isalnum() constin str.o boost::python::detail::str_base::startswith(boost::python::api::object const&) constin str.o boost::python::detail::str_base::startswith(boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::find(boost::python::api::object const&, boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::index(boost::python::api::object const&, boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::rfind(boost::python::api::object const&, boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::rindex(boost::python::api::object const&, boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::find(boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::index(boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::rfind(boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::rindex(boost::python::api::object const&, boost::python::api::object const&) constin str.o boost::python::detail::str_base::endswith(boost::python::api::object const&) constin str.o boost::python::detail::str_base::find(boost::python::api::object const&) constin str.o boost::python::detail::str_base::index(boost::python::api::object const&) constin str.o boost::python::detail::str_base::rfind(boost::python::api::object const&) constin str.o boost::python::detail::str_base::rindex(boost::python::api::object const&) constin str.o _instance_new in class.o boost::python::converter::(anonymous namespace)::slot_rvalue_from_python<int, boost::python::converter::(anonymous namespace)::signed_int_rvalue_from_python<int> >::construct(_object*, boost::python::converter::rvalue_from_python_stage1_data*)in builtin_converters.o boost::python::converter::(anonymous namespace)::slot_rvalue_from_python<long, boost::python::converter::(anonymous namespace)::signed_int_rvalue_from_python<long> >::construct(_object*, boost::python::converter::rvalue_from_python_stage1_data*)in builtin_converters.o boost::python::converter::(anonymous namespace)::slot_rvalue_from_python<signed char, boost::python::converter::(anonymous namespace)::signed_int_rvalue_from_python<signed char> >::construct(_object*, boost::python::converter::rvalue_from_python_stage1_data*)in builtin_converters.o boost::python::converter::(anonymous namespace)::slot_rvalue_from_python<short, boost::python::converter::(anonymous namespace)::signed_int_rvalue_from_python<short> >::construct(_object*, boost::python::converter::rvalue_from_python_stage1_data*)in builtin_converters.o "_PyNumber_InPlaceDivide", referenced from: boost::python::api::operator/=(boost::python::api::object&, boost::python::api::object const&)in object_operators.o "_PyString_InternFromString", referenced from: _function_get_name in function.o "_PyString_Size", referenced from: boost::python::converter::(anonymous namespace)::slot_rvalue_from_python<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::python::converter::(anonymous namespace)::string_rvalue_from_python>::construct(_object*, boost::python::converter::rvalue_from_python_stage1_data*)in builtin_converters.o "_PyFile_FromString", referenced from: boost::python::exec_file(boost::python::str, boost::python::api::object, boost::python::api::object)in exec.o boost::python::exec_file(boost::python::str, boost::python::api::object, boost::python::api::object)in exec.o "_PyString_Type", referenced from: _PyString_Type$non_lazy_ptr in str.o "_PyInt_FromLong", referenced from: boost::python::numeric::aux::array_base::argmin(long)in numeric.o boost::python::numeric::aux::array_base::argmax(long)in numeric.o boost::python::numeric::aux::array_base::argsort(long)in numeric.o boost::python::detail::returnable<boost::python::api::object>::type boost::python::call<boost::python::api::object, long, long, long>(_object*, long const&, long const&, long const&, boost::type<boost::python::api::object>*)in numeric.o boost::python::detail::returnable<boost::python::api::object>::type boost::python::call<boost::python::api::object, long, long, long>(_object*, long const&, long const&, long const&, boost::type<boost::python::api::object>*)in numeric.o boost::python::detail::returnable<boost::python::api::object>::type boost::python::call<boost::python::api::object, long, long, long>(_object*, long const&, long const&, long const&, boost::type<boost::python::api::object>*)in numeric.o boost::python::detail::returnable<boost::python::api::object>::type boost::python::call<boost::python::api::object, long, long>(_object*, long const&, long const&, boost::type<boost::python::api::object>*)in numeric.o boost::python::detail::returnable<boost::python::api::object>::type boost::python::call<boost::python::api::object, long, long>(_object*, long const&, long const&, boost::type<boost::python::api::object>*)in numeric.o boost::python::detail::returnable<boost::python::api::object>::type boost::python::call<boost::python::api::object, boost::python::api::object, long>(_object*, boost::python::api::object const&, long const&, boost::type<boost::python::api::object>*)in numeric.o boost::python::detail::list_base::pop(long)in list.o boost::python::detail::returnable<boost::python::api::object>::type boost::python::call<boost::python::api::object, long, boost::python::api::object>(_object*, long const&, boost::python::api::object const&, boost::type<boost::python::api::object>*)in list.o boost::python::objects::enum_base::to_python(_typeobject*, long)in enum.o boost::python::objects::enum_base::to_python(_typeobject*, long)in enum.o boost::python::objects::enum_base::add_value(char const*, long)in enum.o boost::python::objects::enum_base::add_value(char const*, long)in enum.o boost::python::objects::enum_base::export_values() in enum.o boost::python::objects::enum_base::export_values() in enum.o _object* boost::python::api::object_base_initializer<unsigned int>(unsigned int const&)in enum.o _object* boost::python::api::object_base_initializer<unsigned long>(unsigned long const&)in class.o boost::python::objects::function_doc_signature_generator::parameter_string(boost::python::objects::py_function const&, unsigned long, boost::python::api::object, bool)in function_doc_signature.o boost::python::objects::function_doc_signature_generator::pretty_signature(boost::python::objects::function const*, unsigned long, bool)in function_doc_signature.o boost::python::api::object::object<int>(int const&)in function_doc_signature.o boost::python::api::proxy<boost::python::api::slice_policies> boost::python::api::object_operators<boost::python::api::object>::slice<int, boost::python::api::slice_nil>(int const&, boost::python::api::slice_nil const&)in function_doc_signature.o "_Py_InitModule4", referenced from: boost::python::detail::init_module(char const*, void (*)())in module.o "_PyString_AsString", referenced from: _enum_repr in enum.o _enum_repr in enum.o _enum_repr in enum.o boost::python::converter::(anonymous namespace)::convert_to_cstring(_object*) in builtin_converters.o boost::python::converter::(anonymous namespace)::slot_rvalue_from_python<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::python::converter::(anonymous namespace)::string_rvalue_from_python>::construct(_object*, boost::python::converter::rvalue_from_python_stage1_data*)in builtin_converters.o ld: symbol(s) not found collect2: ld returned 1 exit status "g++" -dynamiclib -Wl,-single_module -install_name "libboost_python3.dylib" -L"/Library/Frameworks/Python.framework/Versions/3.1/lib" -L"/Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/config" -o "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/libboost_python3.dylib" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/numeric.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/list.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/long.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/dict.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/tuple.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/str.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/slice.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/converter/from_python.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/converter/registry.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/converter/type_id.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/enum.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/class.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/function.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/inheritance.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/life_support.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/pickle_support.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/errors.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/module.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/converter/builtin_converters.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/converter/arg_to_python_base.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/iterator.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/stl_iterator.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object_protocol.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object_operators.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/wrapper.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/import.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/exec.o" "bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/object/function_doc_signature.o" -lpython3.1 -headerpad_max_install_names -Wl,-dead_strip -no_dead_strip_inits_and_terms ...failed darwin.link.dll bin.v2/libs/python/build/darwin-4.0.1/release/threading-multi/libboost_python3.dylib... ...skipped <pstage/lib>libboost_python3.dylib for lack of <pbin.v2/libs/python/build/darwin-4.0.1/release/threading-multi>libboost_python3.dylib... ...failed updating 1 target... ...skipped 1 target... *** *** End Screen dump 1 *** So I changed to 2.7 in the user config file and got: *** *** Start Screen dump 2 *** ./bjam --with-python --user-config=user-config.jam Building the Boost C++ Libraries. Component configuration: - chrono : not building - date_time : not building - exception : not building - filesystem : not building - graph : not building - graph_parallel : not building - iostreams : not building - locale : not building - math : not building - mpi : not building - program_options : not building - python : building - random : not building - regex : not building - serialization : not building - signals : not building - system : not building - test : not building - thread : not building - timer : not building - wave : not building ...patience... ...patience... ...found 1597 targets... The Boost C++ Libraries were successfully built! The following directory should be added to compiler include paths: /Users/me/Desktop/boost_1_49_0 The following directory should be added to linker library paths: /Users/me/Desktop/boost_1_49_0/stage/lib *** *** End Screen dump 2 *** So that seemed to work. I then entered: *** *** Start Screen dump 3 *** $cd libs/python/example/quickstart/ $../../../../bjam toolset=darwin --verbose-test test ...patience... ...patience... ...found 1680 targets... ...updating 17 targets... common.mkdir bin common.mkdir bin/test_embed.test common.mkdir bin/test_embed.test/darwin-4.0.1 common.mkdir bin/test_embed.test/darwin-4.0.1/debug common.mkdir bin/darwin-4.0.1 common.mkdir bin/darwin-4.0.1/debug darwin.compile.c++ bin/darwin-4.0.1/debug/embedding.o darwin.link bin/darwin-4.0.1/debug/embedding testing.capture-output bin/test_embed.test/darwin-4.0.1/debug/test_embed.run ====== BEGIN OUTPUT ====== registering extension module embedded_hello... defining Python class derived from Base... testing derived class from C++... success! running file script.py... Hello World ! success! intentionally causing a python exception... Traceback (most recent call last): File "<string>", line 1, in <module> NameError: name 'unknown' is not defined No errors detected. EXIT STATUS: 0 ====== END OUTPUT ====== **passed** bin/test_embed.test/darwin-4.0.1/debug/test_embed.test common.mkdir bin/test_ext.test common.mkdir bin/test_ext.test/darwin-4.0.1 common.mkdir bin/test_ext.test/darwin-4.0.1/debug darwin.compile.c++ bin/darwin-4.0.1/debug/extending.o darwin.link.dll bin/darwin-4.0.1/debug/extending.so *** *** End Screen dump 3 *** It hangs on the last line so I have to cancel it. I then ran: *** *** Start Screen dump 4 *** $ python2.7 test_extending.py Trying: from extending import * Expecting nothing ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 6, in test_extending Failed example: from extending import * Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[0]>", line 1, in <module> from extending import * ImportError: No module named extending Trying: hi = hello('California') Expecting nothing ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 7, in test_extending Failed example: hi = hello('California') Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[1]>", line 1, in <module> hi = hello('California') NameError: name 'hello' is not defined Trying: hi.greet() Expecting: 'Hello from California' ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 8, in test_extending Failed example: hi.greet() Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[2]>", line 1, in <module> hi.greet() NameError: name 'hi' is not defined Trying: invite(hi) Expecting: 'Hello from California! Please come soon!' ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 10, in test_extending Failed example: invite(hi) Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[3]>", line 1, in <module> invite(hi) NameError: name 'invite' is not defined Trying: hi.invite() Expecting: 'Hello from California! Please come soon!' ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 12, in test_extending Failed example: hi.invite() Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[4]>", line 1, in <module> hi.invite() NameError: name 'hi' is not defined Trying: class wordy(hello): def greet(self): return hello.greet(self) + ', where the weather is fine' Expecting nothing ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 15, in test_extending Failed example: class wordy(hello): def greet(self): return hello.greet(self) + ', where the weather is fine' Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[5]>", line 1, in <module> class wordy(hello): NameError: name 'hello' is not defined Trying: hi2 = wordy('Florida') Expecting nothing ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 19, in test_extending Failed example: hi2 = wordy('Florida') Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[6]>", line 1, in <module> hi2 = wordy('Florida') NameError: name 'wordy' is not defined Trying: hi2.greet() Expecting: 'Hello from Florida, where the weather is fine' ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 20, in test_extending Failed example: hi2.greet() Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[7]>", line 1, in <module> hi2.greet() NameError: name 'hi2' is not defined Trying: invite(hi2) Expecting: 'Hello from Florida! Please come soon!' ********************************************************************** File "/Users/me/Desktop/boost_1_49_0/libs/python/example/quickstart/test_extending.py", line 22, in test_extending Failed example: invite(hi2) Exception raised: Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/doctest.py", line 1248, in __run compileflags, 1) in test.globs File "<doctest test_extending[8]>", line 1, in <module> invite(hi2) NameError: name 'invite' is not defined 1 items had no tests: test_extending.run ********************************************************************** 1 items had failures: 9 of 9 in test_extending 9 tests in 2 items. 0 passed and 9 failed. ***Test Failed*** 9 failures. *** *** End Screen dump 4 *** If I enter bin/darwin-4.0.1/debug, I get this for ls -al: mes-computer-444:debug me$ ls -al total 2688 drwxr-xr-x 6 me me 204 Mar 9 11:36 . drwxr-xr-x 3 me me 102 Mar 9 11:36 .. -rwxr-xr-x 1 barrygriffin me 164080 Mar 9 11:36 embedding -rw-r--r-- 1 me me 472992 Mar 9 11:36 embedding.o -rw-r--r-- 1 me me 530060 Mar 9 11:36 extending.o -rwxr-xr-x 1 me me 199076 Mar 9 11:36 extending.so Why am I hanging? I'd like to get python3 to work with boost but maybe its best to fix the hanging problem first. Thanks, Barry

2 1

[fusion] iterating over a sequence with non-const references
by paul Fultz 04 Apr '12

04 Apr '12

Hi, I would like to iterate over a sequence and preserve the reference/const/non-const of the elements. That is say I have a sequence like this: tuple<int&, int> seq; I would like to this to be true: typeof(deref(begin(seq))) == int& typeof(deref(next(begin(seq)))) == int&& It seems fusion sequences always return a const reference to the element. Is there a workaround to get it to work like this? Or is this just not possible with Boost.Fusion? Furthermore, I would like to use the transformation algorithms (especially push_back, and push_front) and still preserve the reference type. Is that possible, through some workarounds? Finally, would it still be fairly efficient when dealing with references, to copy the tuple and make a new tuple when doing algorithms such as push_back or push_front? Or is the lazy evaluation much more efficient than that? Thanks, Paul Fultz II

3 9

Lambda and placeholders
by Sven Bauhan 02 Apr '12

02 Apr '12

Hi, I just tried to use boost::lambda to prevent from creating an extra Functor class just for one call. This is the code I tried: std::deque<LightningSlice>::const_iterator l = std::find_if( m_lightnings.begin(), m_lightnings.end(), boost::lambda::_1.timeslice().contains(time_) ); with typedef std::deque<LightningSlice> LightningQueue; LightningQueue m_lightnings; //!< The lightnings in timeslices const boost::posix_time::time_period& LightningSlice::timeslice() const { return this->m_period; } Then I get the error: ../LightningIndex.cpp:38: error: 'const struct boost::lambda::lambda_functor<boost::lambda::placeholder<1> >' has no member named 'timeslice' What did I wrong? Thanks, Sven

4 6

regex_replace and Unicode ( Cyrillic ) problem
by valery O 02 Apr '12

02 Apr '12

Hi, I have a string with 2 Cyrillic words новый дом repeated 3 times. I try to regex_replace each occurrance of these words. For this I use std:: string format("$1 красный $2") and regex pattern ("(\\W+)\\s+(\\W+)"), The result is only the last occurrence is replaced,the 2 preceding ones are not. Where is my mistake? My code: #include <iostream> #include <string> #include "boost/regex.hpp" using namespace std; int main(int argc, const char** argv) { std::string str( "новый дом, новый дом новый дом" ); regex regx("(\\W+)\\s+(\\W+)"); std::string format( "$1 красный $2"); cout<<"regex_replace :"<<regex_replace( str, regx, format ); return 0; } I use iMac Intel Core Duo, Mac OSX 10.6.8, IDE - Xcode 3.2.6 Thank you. egersheldster

2 1

[move] Move c-tor template
by Szymon Gatner 01 Apr '12

01 Apr '12

Hi, I am implementing custom smart pointer with move semantics and I am having problems with implementing move constructor with template param. In fact clone_ptr presented in docs suffers from that issue also. This code: class B {} class D: public B {} clone_ptr<D> makeD(); void main() { clone_ptr<B> b = makeD() // gives "error C2440: 'initializing' : cannot convert from 'clone_ptr<T>' to 'clone_ptr<T>'" } adding template <class U> clone_ptr(BOOST_RV_REF(clone_ptr<U>) p) //Move constructor : ptr(p.ptr) { p.ptr = 0; } to clone_ptr class does not help. Additional c-tor seems to be ignored. How to fix that? Cheers, Simon -- Szymon Gatner The Lordz Games Studio www.thelordzgamesstudio.com

2 2

newbie: my program can't find boost libraries
by sparsh mittal 31 Mar '12

31 Mar '12

Hello I am new to boost. In my RHEL linux (no root permission), my program does not find boost installation and says: *** Please install package libboost-filesystem to /home/myself/folder *** Please install package libboost-system to /home/myself/folder I installed latest boost using these instructions<http://www.boost.org/doc/libs/1_42_0/more/getting_started/unix-variants.htm…> . ./bootstrap.sh ----with-libraries=filesystem,system --prefix=/home/myself/folder ./bjam install Can you tell, what is wrong I am doing and anything to add in include path etc. My paths: echo $LD_LIBRARY_PATH /home/myself/folder/lib:/home/myself/ddrive/test/boost_1_49_0/stage/lib echo $CPLUS_INCLUDE_PATH /home/myself/folder/include/ My program has makefile: LD_LIBS += -lboost_filesystem -lboost_system (and others) Thanks and Regards Sparsh Mittal

4 4

Boost container inspector in gdb (linux)...
by Shashank Prasad 31 Mar '12

31 Mar '12

I need to inspect the boost containers (unordered_map, unordered_set etc) in gdb (linux)? How can I do that? Similar stuff for STL containers is available at http://sourceware.org/gdb/wiki/STLSupport, but I couldn't find for Boost anywhere. Thanks a lot for your help!

2 1