November 2003 - Boost-users - lists.preview.boost.org

boost::shared_ptr and stl algorithms
by Bill Eidson 15 Apr '05

15 Apr '05

std::vector< boost::shared_ptr<T> > TVec; I want to write a function object to run std::for_each. to do somework against members of T and accumulate results in functor. My attempts have failed in VC7 with memory errors in my operator() method. struct fo { bool operator()( boost::shared_ptr<T>& t ) { return true; } }; Thanks in advance bille

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Will libraries built on WinNT run on Win98? (MinGW)
by Reed Hedges 31 Mar '05

31 Mar '05

I know that Win98 is not really supported, but is there any chance that libraries (specifically thread and regex) that were build on WinNT using MinGW work on Win98 (in MinGW)? My guess is no, but has anyone tried it? thanks reed

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problem with regex_fwd.hpp
by Stefan Shishkov 29 Dec '03

29 Dec '03

Hi, I had a small problem using boost::regexp on MS VC 6.0, boost 1.30.2. In one of my headers I included regex_fwd.hpp. The compilation failed with: ..\boost-1.30.2\boost/detail/allocator.hpp(215): error C2065: 'assert': undeclared identifier Allocator.hpp does not include <cassert> probably relying that it will be included before it. I solved this problem by including <cassert> before regex_fwd.hpp but may be it is better to change allocator.hpp? Or probably something is wrong with my configuration? Best regards Stefan

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BGL and reversing / moving edges
by joshrose 17 Dec '03

17 Dec '03

G'day, I was hoping someone might be able to tell me if they've run into any situations using BGL where they needed to move (or reverse (i.e. flip the source and target)) an edge within a graph implemented as an adjacency_list. I'm working on an implementation of an algorithm for max. weight bipartite matching ("the assignment problem"), and one of the assumptions in the algorithm is that non-matched edges are directed from one subgraph, A, to the other subgraph, B, and matched edges are directed the other way. Over the course of growing the matching, a simple way to add and remove edges from the candidate set is just to reverse the edge, thus the need for some way to reverse the edge within BGL. I don't think I can just remove and then re-add the edge in the other direction, primarily because doing so will (I believe) invalidate any edge_descriptors referring to that edge. In particular, there are property maps keeping track of the weight of edges, the predecessors of certain nodes, etc. that use edge descriptors as keys. I've spent a fair bit of time reading the documentation and looking through the implementation of adjacency_lists (incl. edge_list_impl), and I'm not really sure of a way to either move an edge directly within a graph, or even to create a new edge from another s.t. they have the same edge_descriptor (in general a bad thing, probably). Anyone have any thoughts on this? Thanks, -Josh

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Boost Software License: redistribute modified works?
by Steve M. Robbins 16 Dec '03

16 Dec '03

Hi, I've a question for the drafters of the Boost Software License - Version 1.0 - August 17th, 2003. Put yourself in the position of someone who wants to redistribute a modified version of Boost. For example, the linux distributors like Debian. The license begins with the permission grant: Permission is hereby granted, free of charge, to any person or organization obtaining a copy of the software and accompanying documentation covered by this license (the "Software") to use, reproduce, display, distribute, execute, and transmit the Software, and to prepare derivative works of the Software, and to permit third-parties to whom the Software is furnished to do so, all subject to the following: [... a restriction and a disclaimer paragraph ...] As I read this, "the Software" means "the unmodified tar or zip file obtained from boost.org". Is that correct? I'm permitted to "prepare derivative works of the Software", but the license doesn't specify what I may do with my derivative works. Clearly, I may distribute "the Software", but may I distribute the derivative work? Some licenses (e.g. the BSD and the GPL) make it clear that the terms apply to both the software and to derivative works. Shouldn't the boost license do likewise? -Steve

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ublas + msvc 7.1
by Witz 01 Dec '03

01 Dec '03

hi, I seem to be having problems with ublas in combination with msvc 7.1. Compiling the code below results in a whole slew of errors of the form: 'use of undefined type 'boost::numeric::SOME_MATRIX_TYPE<ARGS>::const_iterator2' Am i doing something dumb or is something broken? #include <boost/numeric/ublas/triangular.hpp> int main() { using namespace boost::numeric::ublas; triangular_matrix<int,lower> ldm(4,4); } I.M.Whittley

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Vertex descriptors in adjacancy_list
by Ali Tofigh 01 Dec '03

01 Dec '03

Is there any guarantee that Vertex descriptors are some kind of integers? In the examples provided add_edge is called with integers as vertex descriptors. Does the choice of parameters for the adjacency_list graph make a difference on this issue? E.g. whether the we choose vecS or listS as VertexList? If future flexibility of the program being written is a factor (e.g. if we want it to be easy to change the definition of the graphs without necessarily changing other parts of the code) is it better to use add_vertex, followed by add_edge using the vertex descriptors returned by add_vertex? Regards, A. T.

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Re: [Boost-users] Re: ublas + msvc 7.1
by cyril.godart＠bnpparibas.com 01 Dec '03

01 Dec '03

I have noticed something similar with msvc 7.1. Could you try please to locate the first occurence of the error and prefix any template deduced type with "typename". In the example you give: typename boost::numeric::SOME_MATRIX_TYPE<ARGS>::const_iterator2 and check that this precise compile error disappears ? (I have realised the code is boost::ublas'). This does not intend to solve your problem but to point to what vc7.1 is expecting. I am not sure whether that should be strict ISO C++. Regards, Cyril Godart. Internet fuxiaowei9999@hotmail.com@lists.boost.org - 25/11/2003 12:21 Please respond to boost-users(a)lists.boost.org Sent by: boost-users-bounces(a)lists.boost.org To: boost-users cc: Subject: [Boost-users] Re: ublas + msvc 7.1 Hi Whittley: I think this may be a bug in VC7.1. I try it successly under VC6.0 and find that the ublas is develop under VC6.0 with Dinkumware STL in its document. Yours f_x_w ----- Original Message ----- From: "Witz" <witz(a)nildram.co.uk> Newsgroups: gmane.comp.lib.boost.user Sent: Monday, November 24, 2003 9:09 AM Subject: ublas + msvc 7.1 > hi, > > I seem to be having problems with ublas in combination with msvc 7.1. > Compiling the code below results in a whole slew of errors of the form: > > 'use of undefined type > 'boost::numeric::SOME_MATRIX_TYPE<ARGS>::const_iterator2' > > Am i doing something dumb or is something broken? > > #include <boost/numeric/ublas/triangular.hpp> > > int main() > { > using namespace boost::numeric::ublas; > triangular_matrix<int,lower> ldm(4,4); > } > > I.M.Whittley _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users This message and any attachments (the "message") is intended solely for the addressees and is confidential. If you receive this message in error, please delete it and immediately notify the sender. Any use not in accord with its purpose, any dissemination or disclosure, either whole or partial, is prohibited except formal approval. The internet can not guarantee the integrity of this message. BNP PARIBAS (and its subsidiaries) shall (will) not therefore be liable for the message if modified. --------------------------------------------- Ce message et toutes les pieces jointes (ci-apres le "message") sont etablis a l'intention exclusive de ses destinataires et sont confidentiels. Si vous recevez ce message par erreur, merci de le detruire et d'en avertir immediatement l'expediteur. Toute utilisation de ce message non conforme a sa destination, toute diffusion ou toute publication, totale ou partielle, est interdite, sauf autorisation expresse. L'internet ne permettant pas d'assurer l'integrite de ce message, BNP PARIBAS (et ses filiales) decline(nt) toute responsabilite au titre de ce message, dans l'hypothese ou il aurait ete modifie.

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Help! Error in quote.hpp...
by Dan W. 01 Dec '03

01 Dec '03

Hi, first-time poster. Got an automated reply to the effect that my first post would be moderated; but later I got another automated email about the moderator being on vacation; and I'm in a hurry, so I hope it's okay for me to re-post here. I'm using latest betas for Digital Mars, STLport and BOOST, and I'm trying to compile a state-machine using boost's fsm::state_machine. My include line is as follows: G:\boost-1.30.2;G:\boost-1.30.2\boost\mpl;G:\boost-1.30.2\libs\mpl\example\fsm;G:\dm\STLport-5.0-1031\stlport;G:\dm\include Here's the top of my file: ............................................................................... #include <iostream> #include "boost/mpl/list.hpp" #include "state_machine.hpp" namespace mpl = boost::mpl; class rec_frm_sm : fsm::state_machine<rec_frm_sm> { public: ............................................................................... What I get on the output window is: sc rec_frm.cpp -Ae -Aa -r -mn -C -WA -S -3 -a8 -c -gf -IG:\boost-1.30.2 -IG:\boost-1.30.2\boost\mpl -IG:\boost-1.30.2\libs\mpl\example\fsm -IG:\dm\STLport-5.0-1031\stlport -IG:\dm\include -orec_frm.obj Error: G:\boost-1.30.2\boost/mpl/aux_/preprocessed/plain /quote.hpp(7): no type for argument 'T' Error: G:\boost-1.30.2\boost/mpl/aux_/has_type.hpp(23): no type for argument 'T' ..................................... Build failed I'm not sure how to track the include path for quote.hpp and has_type.hpp. I notice there's a link at www.boost.org for tracking header file inclusion, but the link appears to be broken. Any help would be appreciated. Yours. dan

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Re: [Boost-users] Help with function and/or bind libraries
by John.Wismar＠alldata.com 30 Nov '03

30 Nov '03

On Sun, 30 Nov 2003 Douglas Paul Gregor <gregod(a)cs.rpi.edu> wrote: > You can replace the body of get_total with: > > return std::accumulate(myVec.begin(), myVec.end(), 0, > boost::bind(std::plus<int>(), //bind 1 > _1, > boost::bind(&B::stretch_it, //bind 2 > this, > boost::bind(&A::size, //bind 3 > _2)))); > > You can decide whether that's better than the hand-coded loop or not :) >From a maintainability standpoint, I don't think I'll make that switch. ; -) Thanks for the reply, though! (Now I just have to try to figure out what it's doing!) --------------------- John Wismar -- RPI '90 john.wismar(a)alldata.com

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Help with function and/or bind libraries
by John.Wismar＠alldata.com 30 Nov '03

30 Nov '03

Here's the situation I'm trying to remedy, boiled down: class A { public: int size() const; }; class B { public: int stretch_it(int size) const; int get_total() const; private: std::vector<A> myVec; }; int B::get_total() const { int retVal = 0; for (std::vector<A>::const_iterator it = myVec.begin(); it != myVec.end (); ++it) { retVal += stretch_it(it->size()); } return retVal; } I'd love to use std::accumulate() or equivalent instead of a hand-coded loop, but I don't know if it's possible to specify a combination of operations like I have here.... Or if the result would be readable! Any suggestions would be much appreciated! --------------------- John Wismar john.wismar(a)alldata.com

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boost::function - why does this work??
by Matt S Trentini 29 Nov '03

29 Nov '03

Heya Everyone, I am trying to create a generic way to extract a list of objects from another list of objects. Let me explain! Say I have a vector (or any container with fwd iterators and value_type) that contains objects that have a function which returns a long (could actually be any type). I want to iterate over that vector and extract each of the longs into a list (or any container that supports push_back and defines value_type). Something like the following: class HandleClass { public: long handle() const { return val_++; } private: static long val_; }; // ... std::vector<HandleClass> listOfHcs; // ... fill listOfHcs here std::list<long> needToFill; OK so far. I then wrote this extraction function (yes, there are many ways I could have done this - with a functor and using foreach is another possibility worth exploring, but not now :) ). template < class ReturnContainer, class FwdIterator > void Extract(const FwdIterator & itBegin, const FwdIterator & itEnd, ReturnContainer & container, boost::function1<ReturnContainer::value_type, FwdIterator::value_type> f) { for (FwdIterator it = itBegin ;it != itEnd; ++it) { container.push_back(f(*it)); } }; And I was able to do this: Extract(listOfHcs.begin(), listOfHcs.end(), needToFill, &HandleClass::handle); And it worked like a charm. needToFill gets filled and I was happy. :) However we also had containers of _pointers_to_ HandleClasses. So in some cases our vector looked like: std::vector<HandleClass *> listOfHcs; Yet the same code worked! I couldn't, and can't, for the life of me understand what was going on (I expected that I would have to wrap the (*it) in a boost::remove_pointer which worried me because my compiler - MSVC7.0 - doesn't support partial template specialization). Don't get me wrong, I'm happy that it work but can anyone explain what fandangelory is going on inside boost::function (or perhaps it's some C++ magic?) to allow this? Cheers, Matt

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Compilation troubles on BSD..
by Joshua Moore-Oliva 28 Nov '03

28 Nov '03

I'm having trouble compiling code on BSD with boost, specifically boost_filesystem. I'm using gcc 3.2.3 On linux, there is no problem, buit on BSD.. this is what happens. Notice that there is no trouble FINDING -lboost_filesystem to link with, but that I'm getting undefined references to anything boost-related. This compiles without any errors on both BSD and linux, but the linking on BSD is the problem. Has anyone had any experiences getting boost to work on BSD before? Thanks, Josh. <snip> signalConfigReload.o \ signalShutdown.o -o Batcher -L. -lChatsUtils -lConfig -lFfm -lFfmStream -lShared -lboost_filesystem -L/usr/local/pqxx/lib -lpqxx markFinished.o: In function `Batcher::markFinished()': /home/josh/src/mastermailings/code/daemons/Batcher/Batcher/markFinished.cpp:9: undefined reference to `boost::filesystem::path::path[in-charge](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)' /home/josh/src/mastermailings/code/daemons/Batcher/Batcher/markFinished.cpp:9: undefined reference to `boost::filesystem::path::path[in-charge](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)' /home/josh/src/mastermailings/code/daemons/Batcher/Batcher/markFinished.cpp:9: undefined reference to `boost::filesystem::rename(boost::filesystem::path const&, boost::filesystem::path const&)' restore.o: In function `Batcher::restore(Ffm&, std::basic_ifstream<char, std::char_traits<char> >&)': /home/josh/src/mastermailings/code/daemons/Batcher/Batcher/restore.cpp:8: undefined reference to `boost::filesystem::path::path[in-charge](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)' /home/josh/src/mastermailings/code/daemons/Batcher/Batcher/restore.cpp:8: undefined reference to `boost::filesystem::exists(boost::filesystem::path const&)' collect2: ld returned 1 exit status

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graph library: internal property problem
by Vasco Lohrenscheit 28 Nov '03

28 Nov '03

Hello, I have some problems with graph properties. For a project I created a layer above the boost graph library. So i have: template <typename N, typename E, typename GT> GraphNode : public N {} template <typename N, typename E, typename GT> GraphEdge : public E {} template <typename N, typename E> Graph {} with BGL properties like: typedef GraphNode<N,E,GraphTraits> tNode; typedef property <typename tNode::vertex_property, tNode*> NodeProperty; As internal graph properties i use pointers to GraphNode and GraphEdge with property tags defined in N and E, e.g. class LogicState { public: enum vertex_state_t {vertex_state=123;} static const vertex_state_t PropertyTag; } const LogicState::vertex_state_t LogicState::PropertyTag=vertex_state; and template specialization for property_kind: template <> struct property_kind <GraphEdge<LogicState, LogicConstraint, GraphTraits> > { typedef vertex_property_tg type; }; with using put(tNode::PropertyTag, graph, somestate); i get the following compile error: error C2679: binary '=' : no operator found which takes a right-hand operand of type 'GraphEdge<N,E,G> ' (or there is no acceptable conversion) with [ N=LogicState, E=LogicConstraint, G=Graph<LogicState,LogicConstraint>::tGraphTraits ] in line 316 in property_map.hpp: "static_cast<const PropertyMap&>(pa)[k] = v;" I'm using the current cvs version of boost and vc++7.1. Any ideas what can cause this problem ? Why there exist no "=" operator ? Where should it be defined/generated in normal cases ? Without my layer, with pure BGL and BOOST_INSTALL_PROPERTY I had it already working. Shouldn't it also be of type GraphEdge<N,E,G>* ? I've checked my code and everywhere I used pointers (in the property definition and with the put). Then another questions: The online docs for the BGL weren't very helpfull for me. Is the BGL book better, or is it only an enhanced version of the online docs ? best regards, Vasco Lohrenscheit

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Re: [Boost-install] Installing BOOST1_30_2 under HP UX 11.11 - URGENT
by David Abrahams 27 Nov '03

27 Nov '03

"Lalit Seth" <laalit_seth(a)hotmail.com> writes: > hi all, > > I m trying to install BOOST1_30_2 under HPUX11.11 > i did bjam to make > I m hving gcc3.2 on HPUX11.11 > > Its giving me failed 22 targets, > skipped 15 targets > done 384 targets. > > Is this right or do i have to change / add parameters to bjam. > > ITS QUITE URGENT. > > Rgds > Lalit Seth Lalit, First please take your Boost installation problems to the Boost.Users list or Boost.Build list (http://www.boost.org/more/mailing_lists.htm#jamboost) This list is out of commission. Second of all, though I am not sure why we don't have the 1.30.2 regression logs posted so I can check, it's not entirely surprising to see 22 targets failing with GCC-3.2. IIRC It does have bugs which prevent a few libraries from compiling. -- Dave Abrahams Boost Consulting www.boost-consulting.com

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C++Builder and Boost Graph Library
by Guilherme Mello de Moura 26 Nov '03

26 Nov '03

Hi guys, My name is Guilherme and I'm trying to use Boost Graph Library with Borland C++Builder.. I'm getting several compilation errors.. I downloaded the latest BGL version (1.30.2) and tried to compile the first graph example I saw.. Here's what I got: Using Boost Graph Library (BGL) version 1.30.2 with C++Builder 5.0 (6.0).. [C++ Error] tuple_basic.hpp(158): E2434 Template declaration missing template parameters ('template<...>') [C++ Error] tuple_basic.hpp(158): E2238 Multiple declaration for 'element<N,T>' [C++ Error] tuple_basic.hpp(143): E2344 Earlier declaration of 'element<N,T>' I also tried to compile the example tests that come with BGL .. And I got some problems with some of them .. Has anybody had the same problem ?!?! Am I doing something wrong ?!?! Regards, Guilherme Mello de Moura

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unit_test_framework - redirect output
by Steven Ketcham 25 Nov '03

25 Nov '03

Perhaps I am making this difficult or even missing the point but... Can I create tests with the unit_test_framework and redirect the output to a GUI? As it stands this is not possible because of int main(...) being defined. Using Windows 2000. Thanks! -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

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[BGL] Using default_dfs_visitor on a graph with std::list as the vertex type
by sashan 25 Nov '03

25 Nov '03

I'm trying to use a vistitor class on a graph I have defined. The visitor class is very simple and inherits from default_dfs_visitor: class OpenGLVisitor : public boost::default_dfs_visitor { public: OpenGLVisitor(void); virtual ~OpenGLVisitor(void); }; My graph type is: typedef adjacency_list < vecS, listS, directedS > graph_t; The code to perform a dfs on the graph is as follows: graph_t g; depth_first_search(g, visitor(OGLVisitor)); However I get the compiler error (see attachment). If I change the typedef to typedef adjacency_list < vecS, vecS, directedS > graph_t; then there is no error. This seems odd since it should also work when the vertices of the graph use the std::list as their container class. I'm using VC++7.1.

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Using boost::lamba with a vector of shared_ptr's
by Allen Bierbaum 24 Nov '03

24 Nov '03

Hello all. I am having trouble with the boost lambda library. I am convinced that my troubles come from some little thing I am overlooking, but for the life of me I can't seem to find the problem. I have been looking at it for the entire afternoon with no solution in sight. I have included some sample code below showing the basic idea of what I am trying to accomplish. Can anyone provide me with a working solution? The summary is: - I have a vector of shared_ptr's to a class A - That class has a method that returns a value I would like to test for in a find_if call ============================================================ namespace bl = boost::lambda class A { int getInt(); }; class Foo { A bar(); } std::vector<shared_ptr<Foo> > foos; shared_ptr<Foo> foo_ptr; A test_val; test_val = (bl::_1 ->* &Foo::bar )(foo_ptr); int find_int = 10; iter found = find_if(foos.begin(), foos.end(), (bl::_1->* &Foo::bar).getInt() == child_guid); ==================================================================== Can anyone tell me how I can call a method from a lamda method iterating over a sequence of shared_ptrs? And then how do I have this method also call another method? Thanks, Allen

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regex question
by Paul Scruby 24 Nov '03

24 Nov '03

I have question about match_result. How can I find out what was matched from the regular expression? In the boost documentation, the example for regex_search does something similar to this... regex needle("foo|bar"); string haystack("blah bar blah"); string::const_iterator start = haystack.begin(); string::const_iterator end = haystack.end(); boost::match_results<string::const_iterator> what; *unsigned* *int* flags = boost::match_default; * while*(regex_search(start, end, what, expression, flags)) { // please output 'bar' string match(string(what[5].first, what[5].second) + std::string(what[6].first, what[6].second)); cout << "Found '" << match << "'\n"; start = what[0].second; flags |= boost::match_prev_avail; flags |= boost::match_not_bob; } However, this is outputing nothing. I also tried what.str(), but that gave me nothing too. Thanks again, Paul

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problem with lexical_cast<int>(std::wstring)
by Ronnie Lazar 24 Nov '03

24 Nov '03

Hi, I'm trying to use lexical_cast<int>(std::wstring), on msvc6 with STLPort, and I get compilation errors. The reason for them is that DISABLE_WIDE_CHARS_SUPPORT is defined in the beginning of lexical_cast.hpp. If I add a line to undef this, in the file, it compiles and works fine, which leads me to belice that this define sould not really be defined. I searched a little more and found that it is defined because BOOST_NO_INTRINSIC_WCHAR_T is defined. My understanding is that this define specifies that the environment does not have wchar_t as a real type, but as a typedef. Why should this interfere with lexical_cast? Any suggestions on how to work around this (apart from changing lexical_cast.hpp source at my site? Thanks Ronnie Lazar

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problem using function lib in MSVC6
by Kim 22 Nov '03

22 Nov '03

Boost version: 1.30.2 Boost Lib: Function OS: Windows XP Pro SP 1 Dev. Env.: Microsoft VS6 SP 6, .NET 2003 Platform SDK Feb 2003, DirectX9 SDK Problem: Can't get an example similar to the one found in the tutorial to work. // ************************************* #include <boost/function.hpp> #include <functional> struct X { int foo(int v) { return v;} }; int main(int argc, char* argv[]) { boost::function1<int, int> f; X x; f = std::bind1st ( std::mem_fun(&X::foo), &x ); f(5); // Call x.foo(5) return 0; } //*************************************** I get this error message: : error C2784: 'class std::mem_fun_t<_R,_Ty> __cdecl std::mem_fun(_R (__thiscall _Ty::*)(void))' : could not deduce template argument for '<Unknown>' from 'int (__thiscall X::*)(int)'

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Boost.Thread problem with thread_specific_ptr<>::release ?
by Roland 21 Nov '03

21 Nov '03

Dear Boosters! As I am still trying to figure out how to use the thread local storage pointer I found another strange behaviour. Perhaps I am misunderstanding the docs, or this might be a bug. System: VC6.0 CVS Head Problem: When using release on a tss variable, the associated automatic cleanup routine seems not to be updated correctly as it tries to delete the original pointer, instead of the 0-pointer. Example (simple modification of tss.cpp example): boost::thread_specific_ptr<int> value; void increment() { int* p = value.get(); ++*p; } void thread_proc() { value.reset(new int(0)); // initialize the thread's storage for (int i=0; i<10; ++i) { increment(); int* p = value.get(); assert(*p == i+1); } //******** added the following two lines int* p = value.release(); delete p; // deleting the released pointer //******* } int main(int argc, char* argv[]) { boost::thread_group threads; for (int i=0; i<5; ++i) threads.create_thread(&thread_proc); threads.join_all(); } In the debug version the program faults at exit, as the pointers are beeing freed a second time. I suspect the problem lies in the following function, as it does not set the cleanup handler if the value is 0 bool tss::set(void* value) { if (value && m_cleanup) { cleanup_handlers* handlers = get_handlers(); assert(handlers); if (!handlers) return false; cleanup_info info(m_cleanup, value); (*handlers)[m_key] = info; } return !!TlsSetValue(m_key, value); } Regards, Roland Schwarz

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When to use which functors?
by Bruce Johnston 21 Nov '03

21 Nov '03

I'm somewhat new to Boost, but pretty familiar with STL and Loki. I'm a bit puzzled by the wide array of similar-sounding libraries in Boost for dealing with function objects: Lambda, Function, Functional, and Bind/Mem_fn. Why are there so many of these libraries and under what circumstances would I want to choose one over the other? Thanks. - Bruce Johnston Simba Technologies

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RE: [Boost-users] lexical_cast causes level 4 warnings w/ VC7.1
by Sam Partington 21 Nov '03

21 Nov '03

Peter Dimov <mailto:pdimov@mmltd.net> wrote: > Sam Partington wrote: >> >> 4511 and 4512 are useless warnings. They are telling you that the >> copy constructor and assignment operator are inaccessible. Even >> though you're not trying to call them. [...] > >> C4127 is also awkward. As it gives warnings for some common idioms. >> It refers to conditional expressions being constant. > > These warnings can be annoying, but they aren't useless. They do find > bugs. I agree that 4127 can help you find bugs. But I can't think of any situation where 4511 or 4512 will help you find a bug. If you actually try to call an inaccesible copy constructor or assignement operator, then the compiler (correctly) fails to compile it. Thats why I used the word "awkward" rather than "useless" for 4127. I'll happily be proved wrong though. Sam ****************** This e-mail has been sent from Imagination Technologies Limited. PowerVR, Metagence, Ensigma and PURE Digital are divisions of Imagination Technologies Limited. The information contained in this e-mail, including any attachment, is confidential and may be legally privileged. It is intended solely for the addressee(s) and access to this e-mail by anyone else is unauthorised. If you are not the intended recipient, any disclosure, copying or distribution or use of the information contained in this e-mail, is prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender by return e-mail and then delete it from your system. Internet communications cannot be guaranteed to be secure, error or virus-free. The sender does not accept liability for any errors or omissions which arise as a result. Any views expressed in this message are those of the author, except where the author specifies and, with authority, states them to be the views of Imagination Technologies Ltd.

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