January 2003 - Boost-users - lists.boost.org

boost::signal and thread-safety
by svanechel <svanechel＠yahoo.com> 11 Jan '03

11 Jan '03

Hi, The signal FAQ says that currently boost::signals aren't thread-safe. I'm guessing this applies to connecting/disconnecting slots from different threads and calling a signal from multiple threadsl, right? If synchronize access when connecting slots and make sure that only a single thread calls a certain signal, can I then use boost::signal to fire events from objects that do processing in a worker thread? As a secondary question: how far in the future will this thread- safety support be added? Thanks in advance, Sven

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[BGL] missing include in boost/graph/kruskal_min_spanning_tree.hpp
by Jeppe N. Madsen 11 Jan '03

11 Jan '03

Hi, kruskal_min_spanning_tree uses bgl_named_params defined in boost/graph/named_function_params.hpp, which is not included.... rgds Jeppe

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(no subject)
by Wilken, Marc 11 Jan '03

11 Jan '03

Hello, does anyone knows, if a construct like out(blitz::Range(0,2))=inp(blitz::Range(0,2)); (that means accesing and assigning of matrix/vector ranges) exist for boost::numeric::ublas too? Marc This e-mail contains confidential information for the exclusive attention of the intended addressee. Any access of third parties to this e-mail is unauthorised. Any use of this e-mail by unintended recipients such as copying, distribution, disclosure etc. is prohibited and may be unlawful. When addressed to our clients the content of this e-mail is subject to the General Terms and Conditions of GL's Group of Companies applicable at the date of this e-mail. GL's Group of Companies does not warrant and/or guarantee that this message at the moment of receipt is authentic, correct and its communication free of errors, interruption etc.

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BGL, vertex_iterators, listS vs vecS
by sa3h1n <sa3h1n＠yahoo.com> 11 Jan '03

11 Jan '03

BGL gurus: I would like to use listS for vertex and edge lists because of iterator stability. However, if I run the following code: ------------ // use listS typedef adjacency_list<listS, listS> Pgraph; // use vecS typedef adjacency_list<vecS, vecS> Pgraph2; int num_vertices = 2; Pgraph pg (num_vertices); boost::graph_traits<Pgraph>::vertex_iterator vi, vi_end; boost::tie(vi, vi_end) = vertices(pg); Pgraph2 pg2 (num_vertices); boost::graph_traits<Pgraph2>::vertex_iterator vi2, vi_end2; boost::tie(vi2, vi_end2) = vertices(pg2); for (vi, vi2; vi != vi_end && vi2 != vi_end2; vi++, vi2++) { std::cout << *vi << std::endl; std::cout << *vi2 << std::endl; } ------------ I get the following output: ------------ 0x00146e60 <- this is *vi which uses listS 0 <- this is *vi2 which uses vecS 0x00146e78 <- this is *vi which uses listS 1 <- this is *vi2 which uses vecS ------------ One of the problems with this is when I try to display the graph using write_graphviz. Vertex indices turn out be 0x0014e60 etc instead of nice numbers like 0, 1, etc. Tracing execution through the debugger, it appears that vi and vi_end are of type generic_iterator(), whereas vi2 and vi2_end are of type iterator_adaptor() defined in boost/iterator_adaptors.hpp . Unfortunately, this is where my c++ expertise peters out. So what is happenning here? And is there anything I can do to ensure iterator stability while using vecS? Any help will be much appreciated, S

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Re: [boost] boost version 1.27 and 1_25_0
by David Abrahams 10 Jan '03

10 Jan '03

Chunhui Pan <chpan(a)milkyway.gsfc.nasa.gov> writes: > Hi, > > If anyone can give an instruction on how to build > boost 1.27 lib and boost_1_25_0 lib on Red Hat7.2? 1.27 instructions are at: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/boost/boost/tools… And 1.25 instructions are at: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/boost/boost/tools… HTH, -- David Abrahams dave(a)boost-consulting.com * http://www.boost-consulting.com Boost support, enhancements, training, and commercial distribution

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multi_array dinamically built
by Ramón Casero Cañas 10 Jan '03

10 Jan '03

Hi, I would like to dinamically create a multi_array. Something like typedef boost::multi_array<bool, 2> BoolMatrix; typedef boost::multi_array<bool, 2>::index indexBoolMatrix; boost::array<BoolMatrix::index, 2> shape = {{ 5, 8 }}; BoolMatrix *A; // NO MEMORY ALLOCATED ... A = new BoolMatrix(shape); // MEMORY ALLOCATED A.assign(data,data+40); // ELEMENTS INITIALIZED The compiler (gcc 2.95.4) says that this kind of things are wrong. Or didn't I understand how the memory allocation in multi_array works? Cheers, Ramón.

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NEWBIE - building on linux
by gcs_99 <gregsteele＠woodsidenet.com> 10 Jan '03

10 Jan '03

Can anyone point me to directions for building boost under linux. I have installed bjam. When I type bjam -sTOOLS=gcc in my boost root dir I get tons of errors. I understand that much of boost is implemented as templates in header files. Is there an install script to place these in the correct location for gcc? Thanks. G

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request for solaris/forte toolset jamfile
by Dr Bruce Lowery <bruce_lowery＠yahoo.com> 10 Jan '03

10 Jan '03

If anyone has a somewhat working jamfile for solaris/forte, could you post a copy of it? --bruce

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Installing boost regex
by Alisdair Meredith 10 Jan '03

10 Jan '03

We're (still!) in the process up upgrading our software to the latest borland compiler, BCB6 I am now at the stage of trying to get the boost libraries integrated into our builds. After running bjam I get some libboost_regex libs, but these don't seem to be used. Reading the separate install procedure under the regex library, I find another install procedure that produces a set of libraries targetted at BCB that do solve my problems. Is this the correct procedure? Is there any way to integrate this with the jam scripts in the future? If not, should we add a link under installing boost to the separate procedure for the regex libraries? -- AlisdairM Team Thai Kingdom

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stop a thread
by hlh771 <hlh771＠yahoo.com.cn> 10 Jan '03

10 Jan '03

How to stop(or cancel) a thread? Suppose I have a main thread and a worker thread, the worker thread does something looply,and when the main thread get a message indicating the process should exit, I want stop the worker thread,how to do that?I have read other thread library,their thread class supply a method called stop or cancel which stops the thread. Their Implementation is:the thread class has a data member indicating whether the thread should stop,and the thread function looply check the data member whether the thread should stop.Generally the data member's type is a bool or Event. Is it the best way to stop the thread? How the boost to deal with this? Thanks in advance.

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