June 2011 - Boost - lists.preview.boost.org

[context] Floating Point Exception
by Daniel Larimer 17 Jul '11

17 Jul '11

Attempting to use the latest Boost.Context implementation on Mac OS X and everything was going fine except for a few small issues: 1) fcontext_x86_64_sysv_macho_gas.S fails to compile because: fcontext_x86_64_sysv_macho_gas.S:50:Unknown pseudo-op: .type fcontext_x86_64_sysv_macho_gas.S:50:Rest of line ignored. 1st junk character valued 95 (_). fcontext_x86_64_sysv_macho_gas.S:51:Alignment too large: 15. assumed. 2) I can fix those errors by commenting out the .type line and changing to .balign 16 or .align 8 3) Compiled with: gcc-4.5.0 -o fcontext_x86_64_sysv_macho_gas.S.o -c fcontext_x86_64_sysv_macho_gas.S 4) protected_stack() cannot map /dev/zero - solutions were to mkfile -n 1m /tmp/zero and then open that - use ::mmap( 0, size__, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); instead of specifying any file. After getting all of those things "working" I attempted to print out a floating point number and it dies deep inside __ntoa(), but I could get it to crash by doing any floating point operations from within the contexts stack. I noticed that none of the examples test for floating point ops. You might want to include that as part of your standard testing. Dan

2 5

[BGL] Contribute to the Boost Graph Library
by Camillo Anania 15 Jul '11

15 Jul '11

Hi all, I used BGL for around 6 months for my thesis (write a routing algorithm). I highly appreciate the BGL and I'm glad someone did it and generously gives their time to maintain/improve it. So now I would like to contribute to the development of the library and so give back something. Just a brief introduction to my profile: - a bachelor and a master in Computer Engineering - six months of experience using the BGL - good knowledge of C++ - great wish to improve my programming skills and master generic programming technique Can you please indicate me the steps I should do to start to actively help the development process? Thanks Camillo Anania

3 4

[doxygen] CSS/Temple files for Doxygen
by Artyom Beilis 10 Jul '11

10 Jul '11

Hello, Where can I find CSS files/Template files suitable for Doxygen documentation generation? So I can make Doxygen output to have more Boost-like style. Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.sf.net/ CppDB - C++ SQL Connectivity: http://cppcms.sf.net/sql/cppdb/

6 13

Re: [boost] Logging library
by Ivan Le Lann 09 Jul '11

09 Jul '11

----- "Tigran Hayrapetyan" <tigran.human(a)gmail.com> a écrit : > Hello dear Boost community > (...) > Existing logging libraries which I used, are writing log messages > linearly, > just one after another. > In contrast, as we know, almost any application's working structure is > not > linear, but hierarchical instead, i.e. functions which call other > functions, > and so on. (...) > So I decided to implement such logging library. I put it in namespace > "tlog" > by now, for "Tree Logging". In my implementation hierarchical messages > are > presented in XML format, as it is some standard for tree-like data. > There are two attached files. The library itself is in "tlog.hpp" > file, and > "main.cpp" contains a sample application which is using the library > and > writes log to "tlog.xml" file. They are written in MS Visual Studio > 2008. > Log messages are written with help of 4 macros: > > TLOG_INFO( Logger, Text ) : logs > message > with specified text to specified logger with priority "information" > TLOG_WARNING( Logger, Text ) : logs > message with > specified text to specified logger with priority "warning" > TLOG_ERROR( Logger, Text ) : logs > message > with specified text to specified logger with priority "error" > TLOG_SCOPED_NODE( Logger, NodeName ) : opens xml element in > the log > file. The element will be closed at the end of scope, so there is no > need to > close it manually. > > I think that the best way to implement entering/leaving subnodes of > the log > file, is to use scopes of the code. > > Please review run result and the code, and see if it can be useful > for boost. Have you tried Boost.Log and its attributes ? http://boost-log.sourceforge.net/libs/log/doc/html/log/detailed/attributes.… http://boost-log.sourceforge.net/libs/log/doc/html/log/detailed/utilities.h… Ivan

2 2

[graph] bug in ith_bandwidth?
by Joel Young 08 Jul '11

08 Jul '11

Is ith_bandwidth broken? It only measures the distance between indices when the source is greater than the sink. Should it look like this: template <typename Graph, typename VertexIndexMap> typename graph_traits<Graph>::vertices_size_type ith_bandwidth(typename graph_traits<Graph>::vertex_descriptor i, const Graph& g, VertexIndexMap index) { BOOST_USING_STD_MAX(); typedef typename graph_traits<Graph>::vertices_size_type size_type; size_type b = 0; typename graph_traits<Graph>::out_edge_iterator e, end; for (boost::tie(e, end) = out_edges(i, g); e != end; ++e) { int f_i = get(index, i); int f_j = get(index, target(*e, g)); using namespace std; // to call abs() unqualified if(f_i > f_j) b = max BOOST_PREVENT_MACRO_SUBSTITUTION (b, size_type(f_i - f_j)); else b = max BOOST_PREVENT_MACRO_SUBSTITUTION (b, size_type(f_j - f_i)); } return b; } Joel

2 1

[introspection] if a function is not public
by Lorenzo Caminiti 05 Jul '11

05 Jul '11

Hello all, Is there any way (SFINAE, etc) to check at run-time or at compile-time if a member function is not public? class x { public: void f ( ) {}; protected: void g ( ) {}; private: void h ( ) {}; bool is_public(...) { ... } // some implementation void check ( ) { std::cout << is_public(x::f) << std::endl; // 1 std::cout << is_public(x::g) << std::endl; // 0 std::cout << is_public(x::h) << std::endl; // 0 } }; Thanks a lot! --Lorenzo

6 9

Re: [boost] [math] Empirical distribution function
by Denis Arnaud 04 Jul '11

04 Jul '11

2011/6/15 <boost-request(a)lists.boost.org> > Date: Wed, 15 Jun 2011 09:35:49 -0400 > From: er <er.ci.2020(a)gmail.com> > > > distributions< > http://www.boost.org/doc/libs/1_46_1/libs/math/doc/sf_and_dist/html/math_to… > >. > > But an accumulator is just fine for now. By the way, does it mean that if > we > > have a set of 1 million of distinct real numbers, the corresponding > > accumulator will store a pretty big number of counters? > > > > Only if the million are distinct values. Otherwise it keeps each > distinct value + a count. > Ok, that's how I understood it, then (even though I'm not sure that that's the way accumulators are supposed to be used). > I'm glad you like the idea of a wrapper on top of an accu, but I only > plan to do the accu. Please give me a bit of time to do a bit of > maintenance work, though. I'll keep you updated. > It sounds perfect: thanks! D

2 2

Merge Boost.Build branding changes to release
by Vladimir Prus 02 Jul '11

02 Jul '11

I would like to ask for permission to merge a couple of Boost.Build "branding" changes to the release branch: https://svn.boost.org/trac/boost/changeset/72773 https://svn.boost.org/trac/boost/changeset/72793 They are mostly changes in messages, except for a bit in bootstrap.{sh,bat} that installs a differently named binary. Obvious, it would be better to merge that later, and I apologise for doing this at this time, but then: - The change is easy - I've tested it on Windows and Linux, and it does not depend on anything much - Most of associated code changes are already merged to release branch in due time, and leaving this change outside would just make things more confusing. Comments? Thanks, -- Vladimir Prus CodeSourcery / Mentor Graphics +7 (812) 677-68-40

3 4

[gui] Help with a little experiment.
by Germán Diago 01 Jul '11

01 Jul '11

Hello. I'm trying to implement a little experiment of what I see should be the future of c++ guis. For that I'm going to need a handful of proto and fusion, and I have some questions. Besides that, there have been many times that a GUI for boost has been discussed. As I have some questions and something to expose, I thought it would be a good idea to post this message in both boost users and boost developers. I don't have an entire proposal for this, but for now I'm experimenting how a GUI framework should look like in my opinion. My opinion is that it should be AS declarative as possible, so, taking as a backend the gtk framework, I came with a syntax like the following one: #define CONTROLLER_CLASS GuiController #include <Gui/Layout.h> #include <iostream> class GuiController { void onEntryChanged(Entry & entry) { auto text = entry.getText(); std::cout << text << std::endl; } void onButtonClick(Button & button) { std::cout << "Button was clicked" << std::endl; } }; auto gui_definition = Window(title="Hello, world!") << VBox(expand=true) << HBox(expand=true) << Label(text="Name:") && Entry[SLOT(onEntryChanged)]) << End(HBox); << Button(text="hello")[SLOT(onButtonClick)]; << End(VBox) << End(Window); The properties are mapped to objects like title corresponding to the gtk properties. The << operator means insert into and the << End(WidgetName) means that no more widgets should be inserted inside that closed widget. The && operator means put widgets at the same level. Regarding signals, they're put inside operator[]. That gui definition would be used like this template <class UI, class Controller> ?? createGUI(UIDefinition & ui_def, Controller & controller); int main(int argc, char * argv[]) { GuiController controller; auto window = createGUI(gui_definition, controller); window.show_all(); window.run(); } The function createGUI would generate a GUI from the definition and it would bind SLOTS automagically. It's very little code making use of a DSEL. The problem is that I must learn a lot of proto to code this, but if it works, do you think it would be an improvement? It's all compiler-checkable and the code is very short. After this first step I could start thinking beyond gtk and separate the library in backend and frotend so that not just gtk+ is used. My question is: Can I make something like End(VBox) work with boost.proto? I mean if it's possible to close the expression for a VBox with end and insert the next widget to the same level that the HBox. Thanks for your time and feedback is welcome.

15 30

boostcon10 blip.tv videos 'missing'
by Michael Caisse 01 Jul '11

01 Jul '11

blip.tv has links for the videos from last year and the text and thumbnail image... but it is missing the actual video. Actually it says "Sorry, this episode may have jut been added to blip.tv and isn't quite ready to watch yet. Please try again later." Any ideas? -- Michael Caisse Object Modeling Designs www.objectmodelingdesigns.com

3 2