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Re: linker problem with boost::thread
by Eske Christiansen 03 Nov '02

03 Nov '02

sorry, have fixed the problem. the correct way of linking with boost::thread is: g++ foo.cpp -lboost_thread -lpthread yours eske

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Making boost/test pause so the console can be read when running the tester from an IDE.
by Sean Shubin 03 Nov '02

03 Nov '02

My version of C++ builder does not pause to let me see console output. This makes it difficult to use boost/test while I am running the program from the IDE. The solution I found most useful, is to make the last test wait for the user to press enter. If anyone has solved this a different way, I would like to hear about it. #include <boost/test/unit_test.hpp> using boost::unit_test_framework::test_suite; using std::cout; using std::cin; using std::endl; void waitForUserToPressEnter() { cout << "Press <ENTER> to continue..." << endl; cin.get(); } test_suite* init_unit_test_suite(int argc, char* argv[]) { test_suite* test = BOOST_TEST_SUITE("Master test suite"); //add other tests here test->add(BOOST_TEST_CASE(&waitForUserToPressEnter)); return test; }

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linker problem with boost::thread
by Eske Christiansen 02 Nov '02

02 Nov '02

Hi all I'm new to this list and I have a question. I want to use the thread lib in g++ 2.96.110 under redhat 7.3 I have the test e.x. #include <boost/thread/thread.hpp> #include <iostream> void hello() { std::cout << "Hello world, I'm a thread!" << std::endl; } int main(int argc, char* argv[]) { boost::thread thrd(&hello); thrd.join(); return 0; } (from cuj.com) I try to compile with g++ -lboost_thread foo.cpp I get the the error(s): /tmp/ccdoKT37.o: In function `main': /tmp/ccdoKT37.o(.text+0x53): undefined reference to `boost::thread::thread(boost::function0<void, boost::empty_function_policy, boost::empty_function_mixin, allocator<boost::function_base> > const &)' /tmp/ccdoKT37.o(.text+0x75): undefined reference to `boost::thread::join(void)' /tmp/ccdoKT37.o(.text+0x86): undefined reference to `boost::thread::~thread(void)' /tmp/ccdoKT37.o(.text+0xbe): undefined reference to `boost::thread::~thread(void)' collect2: ld returned 1 exit status What do I do wrong. I don't want to use jam og bjam files because all my works i build by using automake. yours eske

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Basic Overviews Needed
by Sam Gentile 02 Nov '02

02 Nov '02

Hi Folks, I am new to Boost. I have looked at the Boost Documentation on the web (http://www.boost.org/libs/libraries.htm) and although it does a very excellent job of listing all the libraries, it doesn't really have any overview documents or tutorials as such. What I would like is some documents that tell me the power of Boost, what its useful for, etc. Any help would be greatly appreciated. Sam Gentile .NET Consultant ManagedCode(a)attbi.com http://www.samgentile.com http://radio.weblogs.com/0105852/ [Non-text portions of this message have been removed]

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compiler warning
by Matthew Galati 01 Nov '02

01 Nov '02

hi, using gcc version 2.96 20000731 (Red Hat Linux 7.3 2.96-110) does anyone know the pragma for turning this compiler warning off? or is this warning telling me something - do i need to configure my compiler differently? /home/mgalati/source/boost_1_29_0/boost/integer_traits.hpp:186: warning: ISO C++ does not support `long long' thanks, matt

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RE: [Boost-Users] Making boost/test pause so the console can be read when running the tester from an IDE.
by Sean Shubin 01 Nov '02

01 Nov '02

Tried it. The "return test" line completes the creation of the tests, but not their execution. When that breakpoint is reached, the tests have not been run, so there is not output. -----Original Message----- From: Jeff Garland [mailto:jeff@crystalclearsoftware.com] Sent: Friday, November 01, 2002 2:37 PM To: Boost-Users(a)yahoogroups.com Subject: RE: [Boost-Users] Making boost/test pause so the console can be read when running the tester from an IDE. > My version of C++ builder does not pause to let me see console output. This makes it > difficult to use boost/test while I am running the program from the IDE. The solution > I found most useful, is to make the last test wait for the user to press enter. If > anyone has solved this a different way, I would like to hear about it. Set a breakpoint on return test... HTH, Jeff

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Iterator Adaptor Question
by Hickman, Greg 01 Nov '02

01 Nov '02

The following code illustrates a problem I'm having trying to use iterator_adaptor. Basically, I have a container of shared pointers to mutable, and I'd like to provide a const_iterator to clients that disallows modification of both the shared pointer as well as the pointee. Specifically, I'd like to prevent clients from writing the two lines preceeding the return from main below. Can anyone help? Thanks, Greg #include <boost/iterator_adaptors.hpp> #include <boost/shared_ptr.hpp> #include <vector> using namespace boost; using namespace std; struct Shape { virtual ~Shape() {} virtual void draw() const = 0; virtual void update() = 0; }; struct Concrete_shape : Shape { void draw() const {} void update() {} }; typedef shared_ptr<Shape> Shape_ptr; typedef shared_ptr<const Shape> Const_shape_ptr; struct Picture { typedef vector<Shape_ptr> Shapes; // Declare a const_iterator that converts // to the underlying Shape_ptr to a // Const_shape_ptr. Since the returned // Const_shape_ptr is a temporary, clients // shouldn't be allowed to modify it. typedef iterator_adaptor< Shapes::const_iterator, default_iterator_policies, value_type_is<Const_shape_ptr>, reference_is<const Const_shape_ptr>, iterator_category_is<input_iterator_tag> > const_iterator; const_iterator begin() const { return const_iterator(shapes_.begin()); } Shapes shapes_; }; int main(int argc, char* argv[]) { Picture pic; const Picture& cpic = pic; pic.shapes_.push_back(Shape_ptr(new Concrete_shape)); Picture::const_iterator i = cpic.begin(); // I'd like to prevent clients from writing... i->reset(new Concrete_shape); *i = Const_shape_ptr(new Concrete_shape); return 0; }

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Property Map deep copy
by Björn Lindberg 01 Nov '02

01 Nov '02

I have an external iterator_property_map to an adjacency_list, using std::vector to store std::string as values. I need to copy this map, but a deep copy so that all the strings are unique to the copy. Is there an easy way to do this? I thought about constructing a new property map from a copy of the underlying vector, but this presents two other questions: (i) will the vertex-to-string mappings of the old map still be valid in the constructed copy? (ii) is there a way to extract the underlying vector from the property map? I couldn't find information on this in the online documentation. Björn

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[BGL] How to prune a BFS or exit a BFS
by kweeheong 01 Nov '02

01 Nov '02

I have a custom BFS visitor used to traverse a graph. Is there a built-in way to - prune off a vertex's descendants from the search - exit a BFS These ( pruning and terminating ) are separate situations. I believe the following will work; however, I do not know how to access the relevant data structures. - To prune off a vertex's descendents from the search In the custom BFS visitor's discover_vertex event, set the color of all its adjacent descendants to "black". - To exit a BFS In the custom BFS visitor's discover_vertex event, once the required vertex is found, empty the queue of vertices. How can I access a vertex's color and a BFS's queue? Or is there a better way?

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How to pass result of boost::bind to arg of template function ?
by hugo duncan 31 Oct '02

31 Oct '02

Hi, I want to pass the result of a boost::bind as an argument of a templated function of a class, and am struggling to find a signature that will let me do this. Is this possible? if so what signature should the function have ? Any help much apreciated Hugo #include "boost/function/function1.hpp" #include "boost/bind.hpp" class another_class {}; class my_class { public: typedef another_class ObjectType; //! this works fine passing a boost::function object template <class ReturnType> void add(const boost::function1<ReturnType,ObjectType>& arg) { boost::function1<ReturnType,ObjectType> fn_obj=arg; } //! this should work when passed the result of a boost::bind template <class ReturnType> void add(?what goes here? & arg) { function1<ReturnType,ObjectType> fn_obj(arg); } }; int fn(another_class,int) { return 1; } int main(int, char**) { my_class c; c.add(boost::bind(&fn,_1,1)); }

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[bgl] breadth_first_search for shortest paths (fwd)
by Joel Young 31 Oct '02

31 Oct '02

Dear Jeremy, et al, I am trying to implement a shortest paths algorithm on a directed graph. As I have unit edge weights, I would rather use breadth_first_search rather than dijkstra. // Is this a good candidate for addition? template <class Map, class Tag> struct vertex_marker : public boost::base_visitor<vertex_marker<Map,Tag> > { typedef Tag event_filter; vertex_marker(Map p_map,int p_val) : m_map(p_map),m_val(p_val) { } template <class Vertex, class Graph> void operator()(Vertex v,const Graph&) { boost::put(m_map,v,m_val); } Map m_map; int m_val; }; template <class Map, class Tag> vertex_marker<Map,Tag> mark_vertices(Map p_map, Tag, int p_v) { return vertex_marker<Map,Tag>(p_map,p_v); } boost::breadth_first_search( mygraph, rootnode, boost::visitor(boost::make_bfs_visitor( std::make_pair( boost::record_distances( boost::get(boost::vertex_distance,mygraph), boost::on_tree_edge()) , std::make_pair( mark_vertices( boost::get(boost::vertex_distance,mygraph), boost::on_initialize_vertex(), std::numeric_limits<int>::max()) , mark_vertices( boost::get(boost::vertex_distance,mygraph), boost::on_start_vertex(), 0) ) ) )) ); The problem is that on_start_vertex does not seem to be implemented for breadth_first_search, but it is for depth_first. For dijkstra, the start node seems to be automaticly zeroed. I guess I could mod Am I missing something really obvious here or is there an inconsistency across the algorithms? Shouldn't on_start_vertex be used for all of the graph algorithms? Also, I can't seem to find documentation on neighbor_bfs.hpp Thanks, Joel

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Debug regex++ in VC6
by r_gharavi 31 Oct '02

31 Oct '02

When I build a stand-alone debug xll with regex++ (static linking), Excel refuses to accept it as an addin. It works fine in release mode. Due to reasons beyond my control :-), I am using VC6 STL. Any pointers would be appreciated. Thanks.

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d_heap bug
by Tsvetomir Valtchev 31 Oct '02

31 Oct '02

[I tried to contact the library's author, dietmar.kuehl@claas- solutions.de, but the message bounced back.] Dear Dietmar, I was looking for a better heap class than the one in STL and I was delighted to come across your d_heap class included in the Boost library. Unfortunately, I had a number of problems with it, and I figured you might be interested in some feedback. First, the class didn't compile with VC.NET (and probably won't with VC 6 either). This might be due to non-conformance on the part of Microsoft's compiler and some known limitations with template support, but for some of the issues I think they were due to the non- conformance of the code itself. Second, to my dismay, the code turned out to be seriously flawed. The following simple fragment, for example, causes a crash: THeap::pointer ptrs[10]; ptrs[0] = heap.push(12); ptrs[1] = heap.push(16); heap.remove(ptrs[0]); heap.remove(ptrs[1]); After some debugging and deciphering of the code, I found that the remove() function didn't handle a special case where the node to be 'sifted up' coincided with the last "hole" left in the tree. I think pop() had a similar problem. (In my fixed version, I have expressed pop() in terms of remove(), which resolves the problem and also avoids some code duplication.) I hope some day you get around to publishing an improved version. Another suggestion I have is some way to make sure that the pointer's passed back by client code are valid. Extensive use of assertions throughout the code might also prevent various programming errors. Regards, // Chango V.

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Regex++ and UTF-8
by Gitit 31 Oct '02

31 Oct '02

Hi, We want to use regex++ (version 3.31) with UTF-8 strings. I tried to match a UTF-8 character of 2 bytes to the regex "." and the match failed. It seems regex++ handles these 2 bytes as two separate characters. 1) Is there a "native" way in the regex++ library for using UTF-8 strings? Can we use UTF-8 strings to compare against a compiled regex (the regex is in ASCII only)? Can the regex itself hold UTF-8 characters? 2) Is converting to wchar_t our only option? As far as I understand, wchar_t does not cover the entire range of characters covered by UTF-8, so it may not be enough. Any other ideas? thanks, Gitit.

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Re: [Boost-Users] Re: regex: flag for "global" search?
by dick.bridges＠tais.com 30 Oct '02

30 Oct '02

The boost::regex_search example bumps the start to march through the sub-expressions and the boost::regex_grep examples demonstrate using the 'callback' for each term. I was kinda hoping the library provided a "convenience version" that would take something like "(\\w+)(?:\\.(\\w+))*" and populate the match_results as if the terms had been expanded <e.g.> "(\\w+)(?:\\.(\\w+))?(?:\\. (\\w+))?(?:\\.(\\w+))?"</e.g.> Perhaps to some arbitrary limit? Oh well, given the riches provided, a little while loop now and then is surely a small price to pay. ;) Thanks for the response. I'm continually amazed at the ethos fostered by Boost group members. "Edward Diener" <eddielee@tropic To: boost-users(a)yahoogroups.com soft.com> cc: Sent by: news Subject: [Boost-Users] Re: regex: flag for "global" search? <news(a)main.gmane .org> 10/29/2002 04:54 PM Please respond to Boost-Users Use boost::regex_grep. The boost::regex_search only finds the first match. <dick.bridges(a)tais.com> wrote in message news:OF6181960C.1A0F5C63-ON88256C61.006996C6@tais.net... > I'm trying to capture the sub-expressions in a fqdn (e.g., > one.two.three.com.) One piece of Perl-speak for the expression is: "/ > (\w+)\./g". I've been using boost_search and trying variations on "(?: > (\\w+)\\.)+" but I can't seem to get all the sub-expressions into the > match_results. > > There's got to be a flag I've been overlooking. Any suggestion will be > appreciated. Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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regex: flag for "global" search?
by dick.bridges＠tais.com 30 Oct '02

30 Oct '02

I'm trying to capture the sub-expressions in a fqdn (e.g., one.two.three.com.) One piece of Perl-speak for the expression is: "/ (\w+)\./g". I've been using boost_search and trying variations on "(?: (\\w+)\\.)+" but I can't seem to get all the sub-expressions into the match_results. There's got to be a flag I've been overlooking. Any suggestion will be appreciated. TIA

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Gcc-3.2, statistic_tests.cpp and <limits>
by pcarlini.rm 29 Oct '02

29 Oct '02

Hi, the PR libstdc++/6718 in the Gcc bug database is about a run time problem with this Boost testcase: paolo:~/Programming/c++/boost_1_29_0/libs/random> a.out Confidence level: 0.99; 1-alpha = 0.01; chi_square(19, 36.191) = 0.99 Running tests on minstd_rand KS: 4750* [0] 9500* [0] equidistribution: a.out: statistic_tests.hpp:571: void generic_counter<RandomA ccessContainer>::operator()(int) [with RandomAccessContainer = std::vector<int, std::allocator<int> >] : Assertion `static_cast<unsigned int>(i) < container.size()' failed. Abort According to Nathan Sidwell and Gaby Dos Reis analysis the problem is due to well known issues with numeric_limits<double>::infinity of 3.2's run time library for which unexpectedly Boost provides no work arounds. On the contrary, 2.95.x worked just fine. Please let me know if you need any additional information, ciao, Paolo.

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AW: [Boost-Users] boost::bind problem
by Jasper, Alexander 29 Oct '02

29 Oct '02

-----Ursprüngliche Nachricht----- Von: Mark Snelling [mailto:mark@bakedbeans.com] Gesendet: Dienstag, 29. Oktober 2002 17:44 An: Boost-Users(a)yahoogroups.com Betreff: [Boost-Users] boost::bind problem [...] typedef priority_queue<shared_ptr<Functor>, vector<shared_ptr<Functor> >, bind(less<int(), bind(&Functor::priority, _1), bind(&Functor::priority, _2))> MyQueue; As far as I know you can't call a function in a typedef. bind(..) is a function call returning a predicate. But does s.o. know how to use bind in this manner. I failed to, since the type of what bind returns is far to complex. And it is required if you want to to use bind in conjunction with maps or the priority_queue's. You have to wrap the call in your own predicate. alex

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boost::bind problem
by Mark Snelling 29 Oct '02

29 Oct '02

Hello, I was wondering if anyone out there in Boost land could give me a hand here? Here's the problem: I have a class A: class A { public: A(int i) : _priority(i) {} int priority() {return _priority;} private: int _priority; }; What I want to do is create a std::priority_queue based on boost::shared_ptr<A> and use boost::bind/compose to create the sorting function required by std::priority_queue. However, when I try and typedef the queue (to save a lot of typing) I get compiler errors on VS.NET. using namespace std; using namespace boost; typedef priority_queue<shared_ptr<Functor>, vector<shared_ptr<Functor> >, bind(less<int(), bind(&Functor::priority, _1), bind(&Functor::priority, _2))> MyQueue; Am I going about this the right way? Any help appreciated. TIA Mark.

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Graph library: parallel edges
by Juerg Tschirren 29 Oct '02

29 Oct '02

With the Boost Graph Library, I try do create an undirected graph that does not allow parallel edges, so far without success. Does anybody have a small example that shows how to do this? Juerg

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Graph library: vertex type
by Juerg Tschirren 29 Oct '02

29 Oct '02

In the Boost Graph Library, is it possible to have a custom-defined type for vertices, e.g., I would like to have boost::graph_traits<Graph>::vertex_descriptor map to std::pair<int,int> Can this be done? If yes, how? Juerg

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Re: [Boost-Users] MSVCNT not used anymore?
by dick.bridges＠tais.com 28 Oct '02

28 Oct '02

Thanks! That worked. The MSVCNT example on http://www.boost.org/tools/build/build_system.htm must be left over from a previous version. Appreciate the quick response. sashan <sashang(a)ihug.co To: Boost-Users(a)yahoogroups.com .nz> cc: Subject: Re: [Boost-Users] MSVCNT not used anymore? 10/29/2002 04:20 AM Please respond to Boost-Users dick.bridges(a)tais.com wrote: >I'm having a senior moment. > >MSVCNT is set to C:\Program Files\Microsoft Visual Studio\VC98 and bjam is >invoked with "-sTOOLS=msvc" but the command line that gets invoked is C: >\Program Files\Microsoft Visual C++\VC98\bin\cl and, of course I get: "The >system cannot find the file specified." > >Where's the instructions for compiling with VC6, SP4? > > This is my command line (saved in a batch file): bjam -sTOOLS=msvc -sBUILD=release -sMSVC_ROOT=D:\msvs\VC98 -sVISUALC=D:\msvs\VC98 I don't think MSVCNT is used see http://www.boost.org/tools/build/msvc-tools.html -- P: Egad! You astound me, Brain! B: That's a simple task, Pinky. Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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MSVCNT not used anymore?
by dick.bridges＠tais.com 28 Oct '02

28 Oct '02

I'm having a senior moment. MSVCNT is set to C:\Program Files\Microsoft Visual Studio\VC98 and bjam is invoked with "-sTOOLS=msvc" but the command line that gets invoked is C: \Program Files\Microsoft Visual C++\VC98\bin\cl and, of course I get: "The system cannot find the file specified." Where's the instructions for compiling with VC6, SP4?

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are examples on maual page ready to run?
by J-S Lin 28 Oct '02

28 Oct '02

The error message is as follows, --------------------------------- g:\C++ notes\test_boost\test_matrix.cpp(14) : error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'boost::numeric::ublas::matrix' (or there is no acceptable conversion) with [ T=double, F=boost::numeric::ublas::row_major, A=boost::numeric::ublas::unbounded_array ] ------------------------------ Much appreciated. J-S Lin

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lexical_cast fails to convert std::string to boost::dynamic_bitset<>
by Klaus Nowikow 28 Oct '02

28 Oct '02

Hi! I am trying to convert a string to a boost::dynamic_bitset using boost::lexical_cast, as in this example: template <class Value> bool GetValue(const std::string& str, Value& val) { try { val = boost::lexical_cast<Value>(str); } catch(boost::bad_lexical_cast&) { return false; } return true; } int main() { std::string str = "01"; boost::dynamic_bitset<> bits; if(!GetValue(str, bits)) { [...] } } The lexical_cast always throws an exception. The problem seems to be in lexical_cast.hpp, where a temporary object is created: Target result; if(!(interpreter << arg) || !(interpreter >> result) || !(interpreter >> std::ws).eof()) throw bad_lexical_cast(); and in dynamic_bitset.hpp, where operator>>(std::basic_istream<CharT, Traits>&, dynamic_bitset<Block, Allocator>&) iterates over the bitset using the size() (which is, of course, 0). I sure could solve my particular problem by providing an explicit template instantiation of the GetValue() function, but I don't want to do this because the code is for a library, and I want to reduce references to other libraries to an absolute minimum. Did I miss something here, or is there a workaround for this problem? Regards, Klaus

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