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

RE: [Boost-users] Using shared_ptr across shared library boundary
by Jim.Hyslop 11 Mar '04

11 Mar '04

Edward Diener wrote: > Is there any problem with using shared_ptr and passing an > instance of it to > a function in another shared library, such as a DLL under > Windows ? Does the > reference count get updated correctly when the copy is passed to a DLL > function, so that when the last shared_ptr in either the > original module or > the DLL goers out of scope, the actual pointer is correctly deleted ? I've been using it successfully across DLL boundaries with no problems. The biggest caveat is to ensure you are using the DLL version of the C Runtime library. If you use the static library version, then each DLL will have its own heap, and a pointer *must* be deallocated in the same DLL in which it was allocated. -- Jim Hyslop Senior Software Designer Leitch Technology International Inc. (http://www.leitch.com) Columnist, C/C++ Users Journal (http://www.cuj.com/experts)

2 1

RE: [Boost-users] Re: Using shared_ptr across shared library boun dary
by Jim.Hyslop 11 Mar '04

11 Mar '04

David Abrahams wrote: > "Edward Diener" <eddielee(a)tropicsoft.com> writes: > > > Is there any problem with using shared_ptr and passing an > instance of it to > > a function in another shared library, such as a DLL under Windows ? > > Works beautifully, even if the two DLLs are using different heaps. Are you sure about the different heaps? It's been my experience (with Visual Studio, at least) that allocating memory in one DLL and deallocating it in another leads to problems. Sometimes it doesn't go noticed, but when it does, it's really noticeable. -- Jim Hyslop Senior Software Designer Leitch Technology International Inc. (http://www.leitch.com) Columnist, C/C++ Users Journal (http://www.cuj.com/experts)

2 1

RE: [Boost-users] Re: Using shared_ptr across shared library boun dary
by Mark Storer 11 Mar '04

11 Mar '04

> Works beautifully, even if the two DLLs are using different heaps. How does that work? Do they both end up with the same allocator... so all the allocations end up on the same heap? --Mark Storer Software Engineer Cardiff Software #include <disclaimer> typdef std::disclaimer<Cardiff> Discard;

1 0

Using shared_ptr across shared library boundary
by Edward Diener 11 Mar '04

11 Mar '04

Is there any problem with using shared_ptr and passing an instance of it to a function in another shared library, such as a DLL under Windows ? Does the reference count get updated correctly when the copy is passed to a DLL function, so that when the last shared_ptr in either the original module or the DLL goers out of scope, the actual pointer is correctly deleted ? If this is not the case, that shared_ptr works correctly across DLL boundaries in the manner described, does instantiating and exporting shared_ptr template instances from the DLL to the module using the DLL solve the problem ?

2 2

boost::thread no parameter?
by GoochRules! 11 Mar '04

11 Mar '04

Greetings, I'm wondering why there is no option to pass a parameter to a thread function with boost's threads. With pthreads and Windows CreateThread I'm used to casting an object to a void*, and retrieving the object within the thread function. The only thing similar with boost::thread seems to be to create a struct with an operator()() and a constructor that takes a void*. operator()() then calls an external function with the passed void*. Just curious about this design decision. --M Peltzer

4 3

Re: [Boost-users] Compiler Generator Tools
by Roel.Sergeant＠pandora.be 11 Mar '04

11 Mar '04

Hi Hossein, I know that Spirit can be used for scanning and lexical analysis, at least that where I use it for. I don't know about the rest, but I guess Spirit will help you out there too. In my little project I use it for parsing XML, HTML and other datafiles. For more info on spirit : http://spirit.sourceforge.net/ If you need a C/C++ parser, you might consider Wave, which uses Spirit, and is highly standard compliant. Hope this helps, Roel. >----- Oorspronkelijk bericht ----- >Van : Hossein Haeri [mailto:powerprogman@yahoo.com] >Verzonden : maandag , maart 8, 2004 01:07 PM >Aan : boost-users(a)lists.boost.org >Onderwerp : [Boost-users] Compiler Generator Tools > >Dear all, > >Who knows where I can find the compiler generation >stuff in the Boost repository? I need scaner, lexical >analyser, compiler, code generator, ... Are there any >such tools in the Boost which can build all of the >above goodies for me? > >TIA, >--Hossein > >__________________________________ >Do you Yahoo!? >Yahoo! Search - Find what you?re looking for faster >http://search.yahoo.com >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users > > >

5 5

Compile problem
by fmonkey＠fmonkey.net 11 Mar '04

11 Mar '04

This may be a silly question, but why does the following code give me a compile error (only on Linux BTW, not Windows): template<typename TreeIterT> void ClassName::compile_something(const TreeIterT& iter, compile_context &ctx) { const TreeIterT::value_type& ident = get_first_leaf(*iter); } In member function `void ClassName::compile_something(const TreeIterT&, CompileContext&)': 128: error: syntax error before `&' token Also: template<typename TreeNodeT> void ClassName::compile_something_else(const TreeNodeT &tree, compile_context &ctx) { TreeNodeT::const_iterator iter = tree.begin(); } In member function `void ClassName::compile_something_else(const 138: error: syntax error before `=' token Any idea what is causing this?

2 1

Graph, inv_adjacency_iterator_generator problem
by Peter Aronsson 10 Mar '04

10 Mar '04

Hi, I have a problem with traversing over all parents of a vertex. If I use (the undocumented?) inv_adjacency_iterator_generator class to return iterators for the parents (predecessors) of a vertex I get a compile error. It worked on an earlier version of the library (in debian testing), but does not work for the latest version(1.31.0). I think the problem is that it can no longer find a suitable constructor. Here is my code: // some typedefs removed...... typedef boost::graph_traits<TaskGraph>::in_edge_iterator InEdgeIterator; typedef boost::adjacency_list<boost::listS, boost::listS, boost::bidirectionalS, VertexProperty, EdgeProperty> TaskGraph; typedef boost::inv_adjacency_iterator_generator<TaskGraph, VertexID, InEdgeIterator>::type ParentsIterator; std::pair<ParentsIterator, ParentsIterator> parents(VertexID v, TaskGraph &tg) { InEdgeIterator e,e_end; tie(e,e_end) = in_edges(v,tg); ParentsIterator c(e),c_end(e_end); // problem here. No suitable constructor. return make_pair(e,e_end); } (Traversing through the children/predecessors works fine.) Regards Peter Aronsson -- _________________________________________________________________ / Peter Aronsson, Phd Student at PELAB (Programming Environments \ | Laboratory ) Department for Computer & Information Science | | Linköping University, Sweden | |=================================================================| | petar(a)ida.liu.se , phone +46 (0)13-28 1737 Room 3B:490 | \_________________________________________________________________/

2 3

mpl lambda facilities
by Matt Calabrese 10 Mar '04

10 Mar '04

I'm trying to create a metafunction which takes in a boost::mpl::vector containing spirit parser types, and yields a vector of the original vector's length plus one with each element representing the parser type made of the recursive boost::spirit::alternative of all of the original parser types from the corresponding element in the original vector and an epsilon_parser at the end. in other words, the metafunction should be able to take in: (using boost::mpl and boost::spirit) vector< chlit<>, strlit<>, range<> > and yield a result: vector< alternative< chlit<>, alternative< strlit<>, alternative< range<>, epsilon_parser > > >, alternative< strlit<>, alternative< range<>, epsilon_parser > >, alternative< range<>, epsilon_parser >, epsilon_parser > where empty is my own parser type, similar to epsilon_parser I'm still new to metaprogramming and the mpl lambda facilities and I'm having some trouble creating a metafunction which produces my desired type. This is what I've come up with, though it doesn't work - I'm assuming because of my second use of mpl::_1 in the nested template parameter of mpl::front in mpl::push_front (which I'd like to have represent the current state of the mpl::fold). template< typename vector_t > struct get_alternatives { typename mpl::fold_backward< vector_t, mpl::vector< epsilon_parser >, typename mpl::push_front< mpl::_1, spirit::alternative< mpl::_2, typename mpl::front< mpl::_1 >::type > >::type >::type type; }; Any help is greatly appreciated. Thanks in advance.

2 1

boost::thread and std::system
by Jerry Swan 10 Mar '04

10 Mar '04

I'd like to be able to issue a call to std::system that will time-out after a specified period. Is it possible to achieve this using the boost::threads library? If so could someone kindly sketch how this might be achieved? TIA, Jerry.

1 0

python library issue migrating from boost_1_30_2 to boost_1_31_0
by Marco Donizelli 09 Mar '04

09 Mar '04

Hi there, when I built the 1_30_2 Python Library, I got: libboost_python.so now, with 1_31_0, I get several libs but that one: libboost_python-gcc-1_31.a libboost_python-gcc-1_31.so libboost_python-gcc-1_31.so.1.31.0 libboost_python-gcc.a libboost_python-gcc-d-1_31.a libboost_python-gcc-d-1_31.so libboost_python-gcc-d-1_31.so.1.31.0 libboost_python-gcc-d.a libboost_python-gcc-d.so libboost_python-gcc-mt-1_31.a libboost_python-gcc-mt-1_31.so libboost_python-gcc-mt-1_31.so.1.31.0 libboost_python-gcc-mt.a libboost_python-gcc-mt-d-1_31.a libboost_python-gcc-mt-d-1_31.so libboost_python-gcc-mt-d-1_31.so.1.31.0 libboost_python-gcc-mt-d.a libboost_python-gcc-mt-d.so libboost_python-gcc-mt.so libboost_python-gcc.so Unless I made a mistake in the building step which prevented libboost_python.so to be created, the first solution that comes to my mind to solve this backward compatibility problem would be to create a symlink from libboost_python.so to one of the new libraries. The question is, what would you recommend: libboost_python-gcc.so or libboost_python-gcc-mt.so (or none of the above, but....) thanks a million marco

2 4

RE: [Boost-users] Re: install? and simple thread program.
by Duong, Sanh N. 08 Mar '04

08 Mar '04

I downloaded the latest version of Python from the website given below and ran it with "rpm --rebuild python2-2.2-2.src.rpm." Python seems to install correctly. I reset my env variables to PYTHON_ROOT=/usr and PYTHON_VERSION=2.2. Yet when I ran bjam, it would say it couldn't find the Python.h file within /usr/include/python2.2/. The directory is there, but its empty. There is an another directory for python1.5. But this version will not compile Boost correctly. Any suggestions or idea of why this is happening? Thanks. Sanh. -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of David Abrahams Sent: Monday, March 08, 2004 1:53 PM To: boost-users(a)lists.boost.org Subject: [Boost-users] Re: install? and simple thread program. "Duong, Sanh N." <SANH.N.DUONG(a)saic.com> writes: >> On Fri, 5 Mar 2004, Michael Glassford wrote: >> >>> "Duong, Sanh N." <SANH.N.DUONG(a)saic.com> wrote in message >>> >> The Boost.Python example should still work just fine, if you follow >> the instructions. bjam doesn't use the mangled library names when >> building with cross-project dependencies. It worked for me just >> now. I went into libs/python/example and did > >> bjam test > >> and everything passed. No funky linking should is needed. > > When running bjam test, in libs/python/example I'd get a lot of errors about > templates and vars not define. Let's see a few of them. > Another thing I noticed, when installing > boost with > > bjam "-sGXX=g++" "-sTOOLS=gcc" "--prefix=/home/boost_1_31_0" install > > it would say, "Skipping Boost.Python library build due to missing or > incorrect configuration couldn't find Python.h in "/include/python" Right. > When I point the PYTHON_ROOT and PYTHON_VERSION to the correct path, I'd get > a lot of errors when compiling. Is there a step I'm missing here? Hard to say without seeing the errors. My guess is that you didn't set them correctly. Did you follow the directions at http://www.boost.org/libs/python/doc/building.html ?? -- Dave Abrahams Boost Consulting www.boost-consulting.com _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

4 3

RE: [Boost-users] Re: install? and simple thread program.
by Duong, Sanh N. 08 Mar '04

08 Mar '04

> On Fri, 5 Mar 2004, Michael Glassford wrote: > >> "Duong, Sanh N." <SANH.N.DUONG(a)saic.com> wrote in message >> news:6A47CB4A48D1EA49A6F7AB618490D649069D8C3C@mcl-its-exs03.mail.saic.com... >> > All, >> > >> > Does anyone have an example of how to install boost and bjam? >> >> See the recently much improved Getting Started guide: >> http://boost.org/more/getting_started.html. > > After you follow those instructions, boost will still not work. > Even if you were right, I think you're painting with too broad a > brush here. But I think you're wrong. > You'll need to create links to all of the mangled library names. For > example, in my case all of the libraries have either "gcc" or > "gcc_1_31" mangled in. However, the examples (or more specifically > the boost.python example) assume that the libraries have unmangled > names. > The Boost.Python example should still work just fine, if you follow > the instructions. bjam doesn't use the mangled library names when > building with cross-project dependencies. It worked for me just > now. I went into libs/python/example and did > bjam test > and everything passed. No funky linking should is needed. When running bjam test, in libs/python/example I'd get a lot of errors about templates and vars not define. Another thing I noticed, when installing boost with bjam "-sGXX=g++" "-sTOOLS=gcc" "--prefix=/home/boost_1_31_0" install it would say, "Skipping Boost.Python library build due to missing or incorrect configuration couldn't find Python.h in "/include/python" When I point the PYTHON_ROOT and PYTHON_VERSION to the correct path, I'd get a lot of errors when compiling. Is there a step I'm missing here? Sanh.

3 2

Compiler Generator Tools
by Hossein Haeri 08 Mar '04

08 Mar '04

Dear all, Who knows where I can find the compiler generation stuff in the Boost repository? I need scaner, lexical analyser, compiler, code generator, ... Are there any such tools in the Boost which can build all of the above goodies for me? TIA, --Hossein __________________________________ Do you Yahoo!? Yahoo! Search - Find what you�re looking for faster http://search.yahoo.com

1 0

Mac OS X link problem
by Adam H. Pendleton 07 Mar '04

07 Mar '04

I am using the Boost libraries, specifically the Spirit portions, on Mac OS X Panther, using XCode. Every time I try to compile my program with the Boost libraries I get a linker error: ld: warning prebinding disabled because of undefined symbols ld: Undefined symbols: boost::throw_exception(std::exception const&) Even if I link against all the boost libraries that were created, I still can't get this program to link. The documentation talks about the libraries being compiled with or without BOOST_NO_EXCEPTIONS, but they don't indicate that the program won't link in either case. What am I doing wrong? ahp

3 7

Boost Users: Review Schedule/Upcoming Reviews
by Jeff Garland 06 Mar '04

06 Mar '04

Below is the most recent updates to the reviews. If you have an interest in these libraries please get involved and submit a review. Library Author Review Mgr Dates Circular Buffer Jan Gaspar Pavel Vozenilek 2004 Mar 5-15 Indexed Set Joaquín M López Muñoz Pavel Vozenilek 2004 Mar 20-30 Assignment Thorsten Ottosen Tom Brinkman 2004 Apr 1-11 Serialization Robert Ramey Jeff Garland 2004 Apr 13-20 Container Traits Thorsten Ottosen Hartmut Kaiser 2004 Apr 28-May 7 Tribool Douglas Gregor - - More IO Daryle Walker - - Iostreams Jonathan Turkanis - - Output Formatters Reece Dunn - - Pointer Containers Thorsten Ottosen - - Named Params David Abrahams & Daniel Wallin - - Wave Hartmut Kaiser - -

1 0

Changing case with regex_format
by Keith MacDonald 06 Mar '04

06 Mar '04

The following useful Perl expressions seem to have been omitted from regex_format: \l lowercase next char \u uppercase next char \L lowercase till \E \U uppercase till \E \E end case modification Was there a good reason for that? The only way I can see to implement those expressions is to take a copy of regex_format.hpp, then hack _reg_format_aux. I think that it would also be necessary to change the undocumented regex_traits class, to do upper case conversion, as it only seems to do lower casing at present. Is there an easier way? Thanks, Keith MacDonald

2 1

install? and simple thread program.
by Duong, Sanh N. 06 Mar '04

06 Mar '04

All, Does anyone have an example of how to install boost and bjam? Does someone also have a simple program using boost and threads. Thanks in advance, Sanh

5 4

Futures revisited
by Slawomir Lisznianski 05 Mar '04

05 Mar '04

Hello, During discussions on possible extensions to Boost.Threads, concept of Futures came up rather frequently. Below, I’d like to introduce a particular implementation available at www.rhapsodia.org of which requirements were defined as follows: 1. Provide means to register exception types with a "Future Registry". Rationale: I find it imperative that users should not have to define a list of exception types on each invocation yielding a Future object. Instead, provide the ability to register exception types with a Future Registry and bundle it with Future objects. I feel that compile time registration should be sufficient. 2. Work under the assumption that asynchronous invocations returning Futures and system threads are not coupled. In particular, Futures implementation should not relay on joining with a particular thread to perform synchronization for returning results. Rationale: Although most prevalent, the technique of joining with a particular thread to synchronize on returning result is too limiting. It implies that each task be run on a dedicated thread, specially created to handle it and destroyed to meet with a caller using a Future. Although this approach may be adequate under certain conditions, it generally tends to be expensive on system resources and disorganizes the application. For example, it’s impossible to control the number of concurrently running threads. It may also perform poorly if executed code happens to run shortly as the overhead of creating a thread and cleaning up after it may be significant. More robust approach is to use a queue and a thread pool for running tasks. This adds complexity on the synchronization side, as we can no longer rely on a lifetime of a thread to join with Future’s result. 3. Ability to utilize Futures with arbitrary code without explicit support for them. Rationale: For implementation to be widely adopted, it should be possible to turn just about any function call into a Future-armored asynchronous invocation. No explicit thread synchronization primitives should be used as well. 4. Implement using existing Boost.Threads facilities only. Rationale: Boost.Threads library provides enough support to implement Futures paradigm that meets requirements listed here. 5. STL and Boost compatible. For example, storing Futures in an STL container. Be strongly typed. Futures implementation and usage patterns must naturally coexist with STL and Boost code. Additionally, compile-time type validation is key to safer code. Attached is a sample file from Rhapsodia library showing the use of Futures. Regareds, Slawomir Lisznianski [ www.rhapsodia.org ]

1 0

Constructor in for adjacency_matrix missing?
by Heiko Bauke 05 Mar '04

05 Mar '04

Hello, since some weeks I'm using the BGL. It's really a great library. But I'm a bit confused about the documentation for the template class adjacency_matrix. According to the BGL-book and also the online documentation there should be three constructors for adjacency_matrix: adjacency_matrix(vertices_size_type n, const GraphProperty& p = GraphProperty()) template <typename EdgeIterator> adjacency_matrix(EdgeIterator first, EdgeIterator last, vertices_size_type n, const GraphProperty& p = GraphProperty()) and template <typename EdgeIterator, typename EdgePropertyIterator> adjacency_matrix(EdgeIterator first, EdgeIterator last, EdgePropertyIterator ep_iter, vertices_size_type n, const GraphProperty& p = GraphProperty()) but actually in boost/graph/adjacency_matrix.hpp is only the constructor adjacency_matrix(vertices_size_type n_vertices) is defined. So it's not possible to construct an adjacency_matrix from a pair of iterators (as it is possible for adjacency_list). Has this constructor been removed or never been implemented? Such a constructor would be very useful for me. Another point that confuses me is that the template parameter GraphProperty for template <typename Directed = directedS, typename VertexProperty = no_property, typename EdgeProperty = no_property, typename GraphProperty = no_property, typename Allocator = std::allocator<bool> > class adjacency_matrix; seams never been used for the implementation of this class. regards, Heiko P.S. I'm using boost 1.30.0. -- -- Gute Sitten haben für die Gesellschaft mehr Wert als alle -- Berechnungen Newtons. (Friedrich II., der Große, 1712-1786) -- Supercomputing in Magdeburg @ http://tina.nat.uni-magdeburg.de -- Heiko Bauke @ http://www.uni-magdeburg.de/bauke

1 0

RE: [Boost-users] Hash Table
by Neil Mackie 05 Mar '04

05 Mar '04

jeff suggested, >>You could also look at the STLPort hast table. I too recently wanted to use a hash table and found that neither VC++ 6 not Boost have one. I investigated STLPort thinking that I could just use a one or two .h files to get a hast table template. I carried out a number if iterations involving installing more and more STLPort files to the point that I might as well have installed the whole thing, something I did not want to do as I already have STL as provided by VC++, and Boost of which I'm using only a very small part. The outcome was that I chose another collection type rather than have two STL implementations installed (who knows what type of problems that would have caused). I understand that VC++ 7 does have a hash table implementation. You have to be very careful looking at the documentation at the Microsoft web site as they appear not to distinguish between documentation for V7 and V6. Regards, Neil J Mackie *********************************************************************************** Ofcom is the regulator for the UK communications industry, with responsibilities across television, radio, telecommunications and wireless communications services. Ofcom exists to further the interests of citizen-consumers as the communications industries enter the digital age. Ofcom has taken over the responsibilities and assumed the powers of the five former regulators it has replaced - the Broadcasting Standards Commission, the Independent Television Commission, Oftel, the Radio Authority and the Radiocommunications Agency. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. This footer also confirms that this email message has been scanned for the presence of computer viruses. Any views expressed in this message are those of the individual sender, except where the sender specifies and with authority, states them to be the views of Ofcom. ***********************************************************************************

1 0

RE: [Boost-users] Hash Table
by Ben Hutchings 04 Mar '04

04 Mar '04

Muhammad Hussain <m <mailto:mhussain@i.kyushu-u.ac.jp> <mailto:mhussain@i.kyushu-u.ac.jp> <mailto:mhussain@i.kyushu-u.ac.jp> hussain(a)i.kyushu-u.ac.jp> wrote: Is there any library in boost that provides hash table and the methods to manipulate it? No, but there are common extensions to the standard containers library (aka STL) that are included with many compilers, called hash_map and hash_set. Unfortunately there are several implementations of these which do not have quite the same interface. Ben.

3 3

Where is the jam_src Makefile?
by Dr Mark H Phillips 04 Mar '04

04 Mar '04

Hi, I am trying to compile a bjam executable from scratch (under Linux). In the file: boost_1_31_0/tools/build/jam_src/README it says: The Makefile (UNIX, NT), build.com (VMS), Build.mpw (Mac MPW) are for bootstrapping. Once jam is built, it can rebuild itself. But I can't find the Makefile anywhere! It is not in that directory, and I can't find it anywhere else? Am I blind, or is it missing? Thanks, Mark.

2 1

Hash Table
by Muhammad Hussain ???? ???? 04 Mar '04

04 Mar '04

Is there any library in boost that provides hash table and the methods to manipulate it? Thanks a lot in advance. Hussain

1 0

filesystem lib and dangling symbolic links
by Andre Hentz 04 Mar '04

04 Mar '04

According to http://www.boost.org/libs/filesystem/doc/operations.htm#remove remove() is supposed to remove symbolic links. However, the source code says: if exists(ph) remove; Shouldn't it be: exists(ph) || symbolic_link_exists(ph) Best, Andre Hentz

1 0