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[asio] basic handle query
by Sean Farrow 28 Feb '11

28 Feb '11

Hi: I need to work with multiple basic handles and have a question: If I have a vector of basic handles and have them associated to the same io_service, do I have to call run everytime a new handle is added? Or will as I'm hoping the first io_service.run pick up the new handles if there added after the initial run call. Any help appreciated. Cheers Sean.

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Can I delete/resize a multi_array??
by Ramon F Herrera 28 Feb '11

28 Feb '11

I recently discovered the multi_array, which was the answer to my prayers: typedef boost::multi_array<string, 2> ExpressionArrayType; ExpressionArrayType exprTable(boost::extents[extreme_row][extreme_col]); But now I need more functionality, which can be either: (1) Erase the current "exprTable" and create a new one, with different dimensions. (2) Resize the current dimensions. I have tried things like: ~exprTable; ~exprTable(); delete &exprTable; I have RTFM and Googled but still could use some guidance.... TIA, -RFH

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[tr1/config] portably including unordered_<X>
by Jim Bell 28 Feb '11

28 Feb '11

It appears that <boost/tr1/unordered_X.hpp> includes the native <unordered_X> when Boost.config says it's able. So if one were writing a portable library that uses boost (or bug-fixing an existing boost component), would including <boost/tr1/unordered_X.hpp> be the way to bring it in, or should one look at BOOST_HAS_TR1_UNORDERED_SET and make a decision that way? There's no mechanism analogous to BOOST_HAS_HASH / BOOST_HASH_<X>_HEADER that has to be navigated, right?

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Re: [Boost-users] boost::asio from C++ Forms App in VS 2010
by Alan Vella 28 Feb '11

28 Feb '11

> On 2/25/2011 3:18 PM, Alan Vella wrote: >> Hi all, >> >> I'm trying to port a C++ project from gcc (on MinGW) to Visual Studio >> 2010 inside a Visual C++ Windows Forms application. The code was >> originally written on a Windows XP 32-bit machine. Now it is being >> ported into a Windows 7 32-bit machine. This project uses quite a few >> boost libraries, including the boost::asio library. When I try to >> compile the code in VS2010 I get the following errors: > > If it's an option, you might try VS2008. I've had boost related compile > failures on VS2010 with code that compiles and runs fine on VS2008. > Hi Dave, Thanks for your reply. Unfortunately compiling the code in VS2008 throws the same kind of errors + more! Did nobody ever come across these errors? The first lines seem to point towards a solution: Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. For example: 1> - add -D_WIN32_WINNT=0x0501 to the compiler command line; or 1> - add _WIN32_WINNT=0x0501 to your project's Preprocessor Definitions. 1> Assuming _WIN32_WINNT=0x0501 (i.e. Windows XP target). But I'm not sure what they mean. Regards, Alan. _______________________________________________________ Unlimited Disk, Data Transfer, PHP/MySQL Domain Hosting http://www.doteasy.com

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[regex] Mitigating mischief and malice
by Jim Bell 28 Feb '11

28 Feb '11

Say you wanted to give web users a boost::regex interface to a set of data, knowing that some will try to use it for mischief and malice. I'm vaguely aware that one can write a regex to consume lots of CPU (denial-of-service attack), but also lots of stack and/or memory. What are the risks and how would you address them? Would you filter out certain classes of regular expressions? Tune it via BOOST_REGEX_NON_RECURSIVE and/or other parameters? Would you forbid it altogether? Thanks in Advance, -Jim

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[range] join() and adaptors::transformed do not play nicely with each other
by Nathan Ridge 27 Feb '11

27 Feb '11

Hello, For the following code: #include <vector> #include <boost/range/adaptor/transformed.hpp> #include <boost/range/join.hpp> using boost::adaptors::transformed; using boost::join; int add1(int i) { return i + 1; } int main() { std::vector<int> A, B; auto joined = join(A | transformed(add1), B); } I get the following compiler errors: In file included from ../shared/test/test.cpp:3:0: ../../lib/boost/boost/range/join.hpp: In instantiation of 'boost::range_detail ::joined_type< const boost::range_detail::transformed_range<int (*)(int), vector<int> >, const vector<int> >': ../../lib/boost/boost/range/join.hpp:40:7: instantiated from 'boost ::joined_range< const boost::range_detail::transformed_range<int (*)(int), vector<int> >, const vector<int> >' ../shared/test/test.cpp:13:48: instantiated from here ../../lib/boost/boost/range/join.hpp:34:7: error: no type named 'type' in 'boost::range_detail::demote_iterator_traversal_tag< boost::detail::iterator_category_with_traversal< input_iterator_tag, boost::random_access_traversal_tag >, boost::random_access_traversal_tag >' ../../lib/boost/boost/range/join.hpp: In instantiation of 'boost::joined_range< const boost::range_detail::transformed_range<int (*)(int), vector<int> >, const vector<int> >': ../shared/test/test.cpp:13:48: instantiated from here ../../lib/boost/boost/range/join.hpp:47:11: error: no type named 'type' in 'boost::range_detail::demote_iterator_traversal_tag< boost::detail::iterator_category_with_traversal< input_iterator_tag, boost::random_access_traversal_tag >, boost::random_access_traversal_tag >' What is going on? Thanks, Nate.

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[range] joining ranges with different value types, then transforming with a polymorphic functor
by Nathan Ridge 27 Feb '11

27 Feb '11

Hello, I would like to do the following with Boost.Range: #include <vector> #include <boost/range/adaptor/transformed.hpp> #include <boost/range/join.hpp> #include <boost/foreach.hpp> using boost::adaptors::transformed; using boost::join; struct A { int x; }; struct B { int x; }; struct C { int x; }; struct to_C { C operator()(A a) const { return C{a.x}; } C operator()(B b) const { return C{b.x}; } }; int main() { std::vector<A> a; std::vector b; BOOST_FOREACH(const C& c, join(a, b) | transformed(to_C())) { // do something } return 0; } Basically, I am joining two ranges with different value types (A and B), then transforming the resulting range with a polymorphic functor (to_C) that converts either of A or B to a common third type, C. When I try to loop through this resulting range, however, I get the following compiler errors: In file included from ../../lib/boost/boost/range/join.hpp:15:0, from test.cpp:3: ../../lib/boost/boost/range/detail/join_iterator.hpp: In member function 'A & boost::range_detail::join_iterator_union< vector<A>::iterator, vector::iterator, A & >::dereference(unsigned int) const': ../../lib/boost/boost/range/detail/join_iterator.hpp:216:42: instantiated from 'boost::range_detail::join_iterator< vector<A>::iterator, vector::iterator, A, A & , boost::random_access_traversal_tag >::A & boost::range_detail::join_iterator< vector<A>::iterator, vector::iterator, A, A & , boost::random_access_traversal_tag >::dereference() const' ../../lib/boost/boost/iterator/iterator_facade.hpp:517:32: instantiated from 'static boost::range_detail::join_iterator< vector<A>::iterator, vector::iterator, A, A & , boost::random_access_traversal_tag >::A & boost::iterator_core_access::dereference( const boost::range_detail::join_iterator< vector<A>::iterator, vector::iterator, A, A & , boost::random_access_traversal_tag > & )' ../../lib/boost/boost/iterator/iterator_facade.hpp:643:67: instantiated from 'boost::iterator_facade<I, V, TC, R, D>::A & boost::iterator_facade< I, V, TC, R, D >::operator *() const' ../../lib/boost/boost/iterator/transform_iterator.hpp:121:31: instantiated from 'boost::detail::transform_iterator_base< to_C , boost::range_detail::join_iterator< vector<A>::iterator, vector::iterator, A, A & , boost::random_access_traversal_tag >, boost::use_default, boost::use_default >::type::C boost::transform_iterator< UnaryFunction , boost::range_detail::join_iterator< vector<A>::iterator, vector::iterator, A, A & , boost::random_access_traversal_tag >, boost::use_default, boost::use_default >::dereference() const' ../../lib/boost/boost/iterator/iterator_facade.hpp:517:32: instantiated from 'static boost::transform_iterator< to_C , boost::range_detail::join_iterator< vector<A>::iterator, vector::iterator, A, A & , boost::random_access_traversal_tag >, boost::use_default, boost::use_default >::C boost::iterator_core_access::dereference( const boost::transform_iterator< to_C , boost::range_detail::join_iterator< vector<A>::iterator, vector::iterator, A, A & , boost::random_access_traversal_tag >, boost::use_default, boost::use_default > & )' ../../lib/boost/boost/iterator/iterator_facade.hpp:643:67: instantiated from 'boost::iterator_facade< I, V, TC, R, D >::C boost::iterator_facade<I, V, TC, R, D>::operator *() const' ../../lib/boost/boost/foreach.hpp:748:58: instantiated from 'boost ::foreach_detail_::foreach_reference< boost::range_detail::transformed_range< to_C, const boost::joined_range<vector<A>, vector > >, mpl_::bool_<true> >::ame boost::foreach_detail_::foreach_reference<T, C>::type = C boost ::foreach_detail_::deref( boost::foreach_detail_::const boost::foreach_detail_::auto_any_base & , boost::foreach_detail_::type2type< boost::range_detail::transformed_range< to_C, const boost::joined_range<vector<A>, vector > >, mpl_::bool_<true> > * )' test.cpp:23:5: instantiated from here ../../lib/boost/boost/range/detail/join_iterator.hpp:71:37: error: no match for ternary 'operator?:' in '(selected != 0u) ? this->boost::range_detail ::join_iterator_union<vector<A>::iterator, vector::iterator, A &> ::m_it2.vector<A>::iterator::operator *() : this->boost::range_detail ::join_iterator_union<vector<A>::iterator, vector::iterator, A &> ::m_it1.vector<A>::iterator::operator *()' Is there a way to do this? Thanks, Nate.

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BGL - color map assertion failed
by Krisztian Sinka 27 Feb '11

27 Feb '11

Hi, I have the following code using Boost Graph Library to use the breadth-first-search: -------- code start -------- template<typename T> class MyVisitor : public boost::default_bfs_visitor{ public: MyVisitor(T& d): boost::default_bfs_visitor(),d_(d) {}; template<typename E, typename G> void tree_edge(E e,const G& g) const { typedef typename boost::graph_traits<G>::vertex_descriptor VD; VD u = boost::source(e,g); VD v = boost::target(e,g); d_[u].parent_ = v; }; private: T& d_; }; ... typedef boost::adjacency_list<boost::listS // out-edges , boost::vecS // vertex set , boost::undirectedS , boost::property<boost::vertex_name_t,IndexT> , boost::property<boost::edge_name_t,IndexT> > GraphT; ... typedef boost::graph_traits<GraphT>::vertex_descriptor VD; ... struct DataMap { DataMap(VD p):parent_(p),distance_(0){}; DataMap():parent_(0),distance_(0){}; VD parent_; int distance_; }; ... typedef std::vector<DataMap> VisitedT; typedef VisitedT::iterator VisitedIterT; // Graph g properly initialized here VisitedT visited(boost::num_vertices(g)); for(VI i=vertices(g).first,iend=vertices(g).second;i!=iend;++i){ visited[*i].parent_=*i; }; MyVisitor<VisitedT> vis(visited); boost::breadth_first_search(g,boost::vertex(0,g),boost::visitor(vis)); -------- code end -------- The compiles OK, but when I run it I got: Assertion failed: (std::size_t)i < pm.n, file C:/boost_1_46_0/boost/graph/two_bit_color_map.hpp, line 86 which is strange as I do not tweak with the color map. From the trials it seems that the "VisitedT" works if it holds "simple" types like vertex decriptor etc and not aggregates. My intention with the DataMap to register the vertex parents and the vertex distance at the same time, when the edge is visited. Is there any limit on the library side or did I something wrong? Thank you and regards, K

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[lexical_cast] locale dependent result?
by Alexander Lamaison 27 Feb '11

27 Feb '11

Is the result of lexical_cast<std::string> locale-dependent? One of my contributors has submitted a fix for a problem he says is caused by lexical_cast adding commas to a port number, e.g.: 65535 becomes "65,535". I'm unable to reproduce this but it may be something specific to his locale. If this is the case, what would be the correct way to get a canonical, locale-independent string from an integer? Thanks. Alex -- Easy SFTP for Windows Explorer (http://www.swish-sftp.org)

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[Review] Phoenix V3: Mini-review starts February 20th
by Hartmut Kaiser 27 Feb '11

27 Feb '11

Hi all, Thomas Heller worked hard to address the outstanding issues of the original Phoenix review. He ported Phoenix to Boost.Proto. As mandated by the original Boost review, we will conduct a mini-review of his Phoenix V3 library. This mini-review starts today, February 20th, 2011 and ends on March 2nd, 2011. ------------------ About the library: The Phoenix library enables FP techniques such as higher order functions, lambda (unnamed functions), currying (partial function application) and lazy evaluation in C++. The focus is more on usefulness and practicality than purity, elegance and strict adherence to FP principles. Phoenix is a very important infrastructure library. It is currently a utility library included with Spirit V2 and therefore is already available for years from the latest Boost distributions (headers: $BOOST_ROOT/boost/spirit/home/phoenix, docs: $BOOST_ROOT/libs/spirit/phoenix, or http://www.boost.org/doc/libs/1_45_0/libs/spirit/phoenix/index.html) ------------------ The code of new Phoenix V3 (that's what we mini-review) can be found at: https://svn.boost.org/svn/boost/sandbox/SOC/2010/phoenix3/ the documentation is at: http://svn.boost.org/svn/boost/sandbox/SOC/2010/phoenix3/libs/phoenix/doc/ht ml/index.html ------------------ Here are the questions raised during the initial review of Phoenix in September 2008 (see here: http://thread.gmane.org/gmane.comp.lib.boost.devel/180753) <quote> We will have a mini review before Phoenix gets merged to SVN to make sure whether the feedback from the v2 review was accommodated. Additionally this review will have to discuss: - the breaking interface changes from v2 - the migration path from boost::bind and lambda to Phoenix - how the interoperability with std::bind is solved (result_of semantics) - C++0x features such as rvalue references and variadic templates - the new extensibility mechanism - unified placeholders and interoperability issues with other Proto-based DSELs (such as Spirit.Qi, Spirit.Karma, and Xpressive) - compile times </quote> Please note that Phoenix already has been accepted as a Boost library. We don't vote about that anymore. The purpose of this mini-review is to discuss if the newly rewritten Phoenix V3 addresses the outstanding issues from the main review. In the end I will have to make the decision whether to include the new library into SVN trunk. I really hope to see your participation in the discussions on the Boost mailing lists! Regards Hartmut Review Manager --------------- http://boost-spirit.com

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