July 2011 - Boost-users - lists.preview.boost.org

[build] cannot specify different version of gcc
by Brodie Thiesfield 25 Aug '11

25 Aug '11

Hi, I'm trying to build boost on CentOS 5.5 using the /usr/bin/gcc44 compiler and I'm running into difficulties with documentation not fitting reality. How do I make this work? What I've tried... Note: I've removed /usr/bin/gcc and /usr/bin/g++ to force errors when gcc44 and g++44 are not used. Using ./bootstrap.sh Building Boost.Jam with toolset ... tools/jam/src/### ### No toolset specified. Please use --toolset option. Setting CC=/usr/bin/gcc44 and CXX=/usr/bin/g++44 (note that this won't work if gcc and g++ exist because then it will default to the gcc toolkit and not the gcc-4.4 toolkit that I want). This builds a number of things (looking at the bootstrap.log) but still gives the following error. Ignoring the error and calling ./bjam then fails. Building Boost.Jam with toolset ... tools/jam/src/### ### No toolset specified. Please use --toolset option. Using ./bootstrap.sh --toolset=gcc gives an error: unrecognized option: --toolset=gcc Using ./bootstrap.sh --with-toolset=gcc gives an error: Building Boost.Jam with toolset gcc... Failed to build Boost.Jam -> bootstrap.log shows that it is trying to build with gcc, which doesn't exist, therefore error. Using ./bootstrap.sh --with-toolset=gcc-4.4 gives an error: Building Boost.Jam with toolset gcc... Failed to build Boost.Jam -> bootstrap.log shows ### Unknown toolset: gcc-4.4 Creating ~/user-config.jam as: import toolset.using ; using gcc : 4.4 : g++44 ; export BOOST_USER_CONFIG=~/user-config.jam Then calling the same ./bootstrap.sh command lines above show no difference. How in the world do I get this thing to use /usr/bin/gcc44 and /usr/bin/g++44 to compile? I think that I'm going to have to create local links ./gcc -> /usr/bin/gcc44 and add the current directory to the path just to get this to build the way that I want it to. This seems crazy. Regards, Brodie

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[multi-index][foreach] Iterating over a sequence index (worked in 1.46, broke in 1.47)
by Maxime van Noppen 03 Aug '11

03 Aug '11

Hi, I use BOOST_FOREACH to iterate of a BMI with a sequence index. The code used to work with Boost 1.46 and before, but broke with Boost 1.47. Am I doing something wrong ? ------------------------ #include <iostream> # include <boost/multi_index/hashed_index.hpp> # include <boost/multi_index/member.hpp> # include <boost/multi_index/sequenced_index.hpp> # include <boost/multi_index_container.hpp> # include <boost/foreach.hpp> using namespace ::boost::multi_index; typedef multi_index_container< int, indexed_by< sequenced<> > > bmi_t; typedef bmi_t::nth_index<0>::type seq_idx; const seq_idx& ret(const seq_idx& idx) { return idx; } int main() { bmi_t b; seq_idx& seq = b.get<0>(); // Works BOOST_FOREACH (int i, seq) std::cout << i << std::endl; // Doesn't compile BOOST_FOREACH (int i, ret(seq)) std::cout << i << std::endl; } ------------------------ Note that the offending part is the 'ret(seq)', without it, the code compiles. The error with g++ 4.6.1 is: > In file included from bmi.cc:9:0: > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp: In destructor ‘boost::foreach_detail_::simple_variant<T>::~simple_variant() [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >]’: > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:256:8: instantiated from here > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp:561:3: error: ‘boost::multi_index::detail::sequenced_index<SuperMeta, TagList>::~sequenced_index() [with SuperMeta = boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, TagList = boost::mpl::vector0<mpl_::na>]’ is protected > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:586:13: error: within this context > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp: In constructor ‘boost::foreach_detail_::simple_variant<T>::simple_variant(const T&) [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >]’: > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:648:95: instantiated from ‘boost::foreach_detail_::auto_any<boost::foreach_detail_::simple_variant<T> > boost::foreach_detail_::contain(const T&, bool*) [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >]’ > bmi.cc:28:3: instantiated from here > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp:549:3: error: ‘boost::multi_index::detail::sequenced_index<SuperMeta, TagList>::sequenced_index(const boost::multi_index::detail::sequenced_index<SuperMeta, TagList>&) [with SuperMeta = boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, TagList = boost::mpl::vector0<mpl_::na>]’ is protected > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:571:9: error: within this context > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp: In copy constructor ‘boost::foreach_detail_::simple_variant<T>::simple_variant(const boost::foreach_detail_::simple_variant<T>&) [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >, boost::foreach_detail_::simple_variant<T> = boost::foreach_detail_::simple_variant<boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> > >]’: > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:256:8: instantiated from ‘boost::foreach_detail_::auto_any<boost::foreach_detail_::simple_variant<T> > boost::foreach_detail_::contain(const T&, bool*) [with T = boost::multi_index::detail::sequenced_index<boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, boost::mpl::vector0<mpl_::na> >]’ > bmi.cc:28:3: instantiated from here > /home/yabo/dev/boost/usr/include/boost/multi_index/sequenced_index.hpp:549:3: error: ‘boost::multi_index::detail::sequenced_index<SuperMeta, TagList>::sequenced_index(const boost::multi_index::detail::sequenced_index<SuperMeta, TagList>&) [with SuperMeta = boost::multi_index::detail::nth_layer<1, int, boost::multi_index::indexed_by<boost::multi_index::sequenced<> >, std::allocator<int> >, TagList = boost::mpl::vector0<mpl_::na>]’ is protected > /home/yabo/dev/boost/usr/include/boost/foreach.hpp:578:13: error: within this context Note that with clang++ 2.9 the code doesn't compile at all either with Boost 1.46 or Boost 1.47. Thanks! -- Maxime

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Bizarre problem with range/adaptor/transformed.hpp
by John M. Dlugosz 02 Aug '11

02 Aug '11

I've traced a problem in my program to the inclusion of #include "boost/range/adaptor/transformed.hpp" Nothing is using the features in it (such things are removed from the test case build I'm using to get to the bottom of it). It compiles just as well with or without the line. But if the file is included, the program is broken. If I omit it, then the program works fine. Any suggestions would be welcome.

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[range] range metafunctions and reference types
by Nathan Ridge 01 Aug '11

01 Aug '11

Hello, The range metafunctions currently do not work on range reference types. For example, the following: #include <vector> #include <boost/range/metafunctions.hpp> typedef boost::range_iterator<std::vector<int>&>::type iter_t; Fails with the errors: In file included from lib/boost/boost/range/iterator.hpp:23:0, from lib/boost/boost/range/metafunctions.hpp:18, from test4.cpp:2: lib/boost/boost/mpl/eval_if.hpp: In instantiation of 'boost::mpl::eval_if_c<false, boost::range_const_iterator<std::vector<int>&>, boost::range_mutable_iterator<std::vector<int>&> >': lib/boost/boost/range/iterator.hpp:72:63: instantiated from 'boost::range_iterator<std::vector<int>&>' test4.cpp:4:49: instantiated from here lib/boost/boost/mpl/eval_if.hpp:60:31: error: no type named 'type' in 'boost::mpl::eval_if_c<false, boost::range_const_iterator<std::vector<int>&>, boost::range_mutable_iterator<std::vector<int>&> >::f_ {aka struct boost::range_mutable_iterator<std::vector<int>&>}' This behaviour is OK when you are doing things like this: template <typename Range> typename range_iterator<Range>::type some_function(const Range& r) { ... } because when called with a "const vector<T>&" argument, template argument deduction will deduce "Range" to be just "vector<T>", and this is what we call the metafunction on. Likewise, if some_function has a non-const version that takes a "Range&" argument, it works fine too. But in C++0x, rvalue references allow us to kill two birds with one stone and have just one function that accepts both const and non-const references: template <typename Range> typename range_iterator<Range>::type some_function(Range&& r) { ... } However, the template argument deduction rules for rvalue references are different: if the function is called with a "const vector<T>&" parameter, "Range" will be deduced as "const vector<T>&", i.e. the reference is preserved. But now range_iterator gives an error as indicated above, so we have to do something awkward and verbose like this: template <typename Range> typename range_iterator<typename remove_reference<Range>::type>::type some_function(Range&& r) { ... } Could the range metafunctions be modified to accept range reference parameters and remove the reference themselves? Thanks, Nate.

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[Serialization] Linker error on BOOST_CLASS_EXPORT upgrading from 1.44.0
by Enrico Carrara 01 Aug '11

01 Aug '11

Hello, I am facing a problem with serialization as implemented in Boost 1.47.0 which I did not experience in version 1.44.0. The problem appears as a series of linker errors (Visual C++ 8.0 (VS2005), WinXP 32bit): 1>Compiling... 1>Model_SerializationXml.cpp 1>Model_SerializationTxt.cpp 1>Compiling manifest to resources... 1>Linking... 1>Model_SerializationXml.obj : error LNK2005: "public: static struct boost::archive::detail::extra_detail::guid_initializer<class sm::CompLoad_Test> const & const boost::archive::detail::extra_detail::init_guid<class sm::CompLoad_Test>::g" (?g@?$init_guid@VCompLoad_Test@sm@@@extra_detail@detail@archive@boost @@2ABU?$guid_initializer@VCompLoad_Test@sm@@@2345@B) already defined in Model_SerializationTxt.obj [...many more similar errors] The scenario is as follows: I have a considerable bunch of classes which must be serialized by means of both text and XML archives. To this purpose, I have two compilation units, "Model_SerializationTxt.cpp" and "Model_SerializationXml.cpp", as follows: ///////////////////////////////////////////////// // Model_SerializationTxt.cpp [...] #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/archive_exception.hpp> [...] #include "SerClassExport.h" [...] ///////////////////////////////////////////////// ///////////////////////////////////////////////// // Model_SerializationXml.cpp [...] #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/archive_exception.hpp> [...] #include "SerClassExport.h" [...] ///////////////////////////////////////////////// ///////////////////////////////////////////////// // SerClassExport.h [...] // APPLICATION_DEPENDENT: Include here files // relevant to model classes to be exported // for serialization #include "Model_Root.h" #include "SM/SM_Node.h" [...Many more class definition headers] [...] #include <boost/serialization/export.hpp> // APPLICATION_DEPENDENT: Include here files // relevant to model classes to be exported // for serialization BOOST_CLASS_EXPORT(model::Root) BOOST_CLASS_EXPORT(sm::Node) [...Many more class export definitions] [...] ///////////////////////////////////////////////// The problem seems to be related to the fact that BOOST_CLASS_EXPORT is defined twice in my project. In Boost 1.44.0, struct guid_initializer was defined in "export.hpp" inside an anonymous namespace, while in Boost 1.47.0 - actually, since version 1.45.0 - the definition is inside namespace extra_detail, even if the comment above is unchanged: ///////////////////////////////////////////////// // export.hpp in Boost 1.44.0 [...] // Note INTENTIONAL usage of anonymous namespace in header. // This was made this way so that export.hpp could be included // in other headers. This is still under study. namespace { template<class T> struct guid_initializer [...] #define BOOST_CLASS_EXPORT_IMPLEMENT(T)\ namespace boost {\ namespace archive {\ namespace detail {\ namespace {\ template<>\ struct init_guid< T > {\ static guid_initializer< T > const & g;\ };\ guid_initializer< T > const & init_guid< T >::g =\ ::boost::serialization::singleton<\ guid_initializer< T >\ >::get_mutable_instance().export_guid();\ }}}}\ [...] ///////////////////////////////////////////////// ///////////////////////////////////////////////// // export.hpp in Boost 1.47.0 [...] // Note INTENTIONAL usage of anonymous namespace in header. // This was made this way so that export.hpp could be included // in other headers. This is still under study. namespace extra_detail { template<class T> struct guid_initializer [...] #define BOOST_CLASS_EXPORT_IMPLEMENT(T)\ namespace boost {\ namespace archive {\ namespace detail {\ namespace extra_detail {\ template<>\ struct init_guid< T > {\ static guid_initializer< T > const & g;\ };\ guid_initializer< T > const & init_guid< T >::g =\ ::boost::serialization::singleton<\ guid_initializer< T >\ >::get_mutable_instance().export_guid();\ }}}}\ [...] ///////////////////////////////////////////////// I guess that this might have a role in originating the linker problem. How can I avoid this error? I already tried including the list of BOOST_CLASS_EXPORT only once, i.e in Model_SerializationTxt.cpp only. This solved the linker problem, but serialization of data in XML was then impossible (runtime error). Unfortunately, merging the two compilation units in one is not possible, because the compiler (Visual C++ 8.0) goes out of memory while compiling the big unit (process memory grows beyond 2GB). Is there, in your opinion, a solution or a workaround to this situation? Let me apologize for the very long mail, I did not succeed in shortening it further. Looking forward to any possible advice, thank you in advance for your attention. Enrico

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[units] How to multiply a quantity with a dimensionless factor
by Marcel 01 Aug '11

01 Aug '11

Hi, I'm new to boost and units and hope this is not too trivial. If I try to multiply a quantity with a dimensionless factor like quantity<length> a; quantity<length> b = 2.0 * b; I get compiler errors due to missing operator*. So I worked around this by using quantity<length> b = quantity<dimensionless>(2.0) * b; But I'm wondering if there is a easier and better readable way to do this? Thank you in advance, Marcel

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[interprocess] garbage chars when extending interprocess strings?
by Anthony Foiani 01 Aug '11

01 Aug '11

I'm having a peculiar problem with interprocess strings. 0. Create the shared string type. typedef boost::interprocess::managed_shared_memory ShmManagerType; typedef char ShmCharType; typedef boost::interprocess::allocator< ShmCharType, ShmManagerType::segment_manager > ShmCharAllocatorType; typedef boost::interprocess::basic_string< ShmCharType, std::char_traits< ShmCharType >, ShmCharAllocatorType > ShmStringType; 1. Initial write succeeds. ShmStringType val; val = "x"; cout << quoteString( x ) << endl; // prints "x" as expected 2. When I overwrite the value with a longer value, the longer value is stored and the length is updated -- but a null character (\0) is inserted at the *old* length. ShmStringType x3( "xxx" ); val = x3; cout << quoteString( val ) << endl; // prints "x\0x" !!! 3. When I write the longer value again, it is stored correctly and there is no \0 in the middle of the string. val = x3; cout << quoteString( val ) << endl; // prints "xxx" as expected 4. The same thing happens if we try a longer value again: ShmStringType x5( "xxxxx" ); val = x5; cout << quoteString( val ) << endl; // prints "xxx\0x" val = x5 cout << quoteString( val ) << endl; // prints "xxxxx" Does this ring bells for anyone? On my embedded platform, I'm using: powerpc e300c3 Linux 2.6.36 eglibc 2.13 boost 1_44_0 g++ 4.5.1 And on my development workstation: intel x86-64 Linux 2.6.35.13-92.fc14 glibc 2.13-1 boost 1.44.0-8.fc14 gcc 4.5.1-4.fc14 Testing this on my development workstation, I see similar issues (although it's not always \0; in this case, I'm getting \xC0 junk characters. Odd!) Test case at: http://foiani.com/cpp/boost/InterProcStringTest.cpp Sample output: http://foiani.com/cpp/boost/ipst-out-ppc32.txt http://foiani.com/cpp/boost/ipst-out-x86_64.txt The output isn't the same: some cases work on one platform but not the other, and the garbage character introduced isn't always \0. Any ideas would be welcome. Testing with a more current boost is a bit problematic; if someone believes that it's been fixed in the mean time, I'll do my best to try with a modern boost. In the mean time, I'll just write the values twice, I guess. :) Thanks for your time and attention! Best regards, Tony

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[Iterator]Can dereference() in iterator_adaptor return a temporary value?
by Remi 01 Aug '11

01 Aug '11

Hi, I'd like a const iterator that acts as a proxy by giving access to elements of type A as if they were elements of unrelated type B. In that case I guess the dereference() member function should return a temporary value, right? Would that be a correct implementation of the idea? Here I just want to access an array of SourceVertexType as if it were an array of VertexType. template<class VertexType> class ConstVerticesIterator : public boost::iterator_adaptor< ConstVerticesIterator<VertexType>, const SourceVertexType*, const VertexType > { private: friend class boost::iterator_core_access; VertexType dereference() const { const SourceVertexType& source_vertex( *base() ); return VertexType( source_vertex.x, source_vertex.y ); } public: explicit ConstVerticesIterator( const SourceVertexType* vertices ) : boost::iterator_adaptor< ConstVerticesIterator<VertexType>, const SourceVertexType*, const VertexType >( vertices ) {} };

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translate C-code into objects
by Peter Foelsche 01 Aug '11

01 Aug '11

Dear All, I would like to translate some C-Code into objects. I did this already for functions and expressions: Writing template functions and passing my expression object as an argument. Now I want to do this for C-Code, which uses if-statements and variables. To do this, I would implement some template function for an if-statement. And some function for an assignment to a variable. Probably using enumerations to indicate the variable. Is this the right approach? Peter

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[foreach] Changes in Boost 1.47 beaking const rvalue detection for some compilers?
by Joaquin M Lopez Munoz 31 Jul '11

31 Jul '11

Hi, According to the discussion at http://lists.boost.org/boost-users/2011/07/69718.php seems like for some non-copyable sequence types, such as indices of Boost.MultiIndex, Boost.Foreach has stopped in GCC 4.6.1 with Boost 1.47 (and did not work in clang++ 2.9 either for Boost 1.46 or Boost 1.47.) Before I apply the boost::foreach::is_noncopyable hack, can the author take a look at this? Release notes for Boost 1.47 indicate that const rvalue detection has been modified in Boost.Foreach, so I wonder whether this situation is something that should be fixed in Boost.Foreach rather than user code. Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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