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Phoenix: error: extra ‘;’ on boost/phoenix/core/environment.hpp
by Vicente BOTET 15 May '11

15 May '11

Hi, There is an error on In file included from ../../../boost/phoenix/core/call.hpp:12, from ../../../boost/conversion/fp/convert_to.hpp:15, from builtins.cpp:16: ../../../boost/phoenix/core/environment.hpp:446: error: extra ‘;’ It seems that the error: extra ‘;’ are on lines 433 and 444 at the end of two functions definitions. Could this be fixed? Thanks, Vicente

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[countertree] New Version
by Francisco José Tapia 15 May '11

15 May '11

Hi this message is to announce the new version of the countertree library. You can find the zip file with the code and the documentation in < http://www.boost-consulting.com/vault/index.php?action=downloadfile&filenam…> or if you want a quick look , you can see in my web page < http://fjtapia.webs.com/works/countertree/index.html> Technically this library is an implementation of a binary red-black counter tree. Colloquially is a balanced tree with an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container. If the information stored is unordered, we have the class boost::vectortree. This class have the same interface than a std::vector. The std::vector is very fast O(k) inserting and deleting at end , but very slow O(N) if you must do in other positions . In the vectortree all the operations are O(logN). It is a bite slower than std:vector inserting and deleting at end, but much more faster for to insert and delete in any other position. If the information stored is ordered, you have the classes boost::set, boost::multiset boost::map and boost::multimap. These classes have identical interfaz than the std::set , std::multiset, std::map and std::multimap, and additionally, access by position with the function at(pos). The iterators are random access and have a function pos() which return their position in the container. You can mix safely access by iterators and access by position. The performance of these classes are similar to the classes of the STL. #include <boost/countertree/set.hpp> #include <iostream> int main ( void ) { //------------------------ begin -------------------- boost::set<int> A ; for ( int i = 0 ; i< 100 ; ++i) A.insert(i); for ( int i = 0 ; i < A.size() ; ++i) std::cout<<A.at(i); return 0 ; }; For to show the utility of this, imagine a large unordered file with the information about the employees of a big company. You have indexes implemented with multimaps, with pairs [value, position], and use the upper_bound and lower_bound functions . You need to select the employees in a range of age and weight. With the boost:multimap you can know the number of elements of the selection. In the weight query we found 100 elements and in the age query 10000 elements. To travel the elements of the weight query asking for the age, is faster than the opposite. Tray it. It fast, useful and easy to understand and use,. They are the STL classes with a few additional functions. I had checked this code with GCC (32 and 64) and Visual Studio 2008 (32) and Visual Studio 1010 (32 and 64). Please, if you find any problem, please mail me ( <fjtapia(a)gmail.com>) or if you mail Boost, please insert [countertree] in the head of the message. Some days I have not time to read all messages arrived to my mail, but if I see that I detect and respond first. Francisco Tapia <fjtapia(a)gmail.com>

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Phoenix: is there a Phoenix expression trait?
by Vicente BOTET 15 May '11

15 May '11

Hi, I'm adding a convert_to Phoenix like functor to Boost.Conversion. I would like to use the same name, i.e. convert_to, but the overloads conflict. I would like to use sfinae to choose the correct overloading between template inline typename expression::convert_to, U>::type const convert_to(U const& u); template Target convert_to(Source const& from, boost::dummy::base_tag const& p=boost::dummy::base_tag()) Is there a trait that can be used to detect if the parameter is a Phoenix expression? BTW, I have just based my implementation on the one for static_cast, that uses the detail boost::phoenix::detail::target Could someone explain me why this is needed? Could this detail be moved to the user interface? Best, Vicente

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[context] new version (stack unwinding, ASIO example, ...)
by Oliver Kowalke 14 May '11

14 May '11

Hello, I've reworked on boost.context regarding to the suggestion of the last review (thanks to Vicente as review manager) - but not all requests could be fulfilled. The new lib supports stack unwinding, has examples like C# enumerator concept (yield_return(), yield_break()) and an adapted version of a echo server using stack-less coroutines written by Chr. Kohlhoff and Java continuations. The new version (boost.context-0.7.0.zip) is published on boost vault and the documentation can be read here : http://ok73.ok.funpic.de/boost/libs/context/doc/html/ . Best regards, Oliver

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[BGL] container_gen (was Re: [tree] reviving the tree library)
by Cromwell Enage 14 May '11

14 May '11

--- On Fri, 5/6/11, Erik Erlandson wrote: > My storage models are effectively wrappers around the > underlying containers (the container is a member of > the node type). I originally thought it would be nice > to allow a user to somehow drop in any container they > wanted, but I was unable to find a way to make that > work properly. [snip] > Perhaps container_gen would allow it to be more fully > automated. The idea behind container_gen is indeed to allow users to drop in containers of their choosing by providing their own specializations and selectors. In turn, your node class template needs only to take in the selector type as an additional template parameter. One current limitation that may be important to you is the inability to supply custom allocators as well. I saw in the sandbox that the BGL authors were planning to provide selector templates parameterized by allocator type. I'm wondering how that work is progressing. At any rate, to the BGL authors: I find container_gen to be a useful utility metafunction outside its current home. Would anyone else like to see it become a first-class Boost citizen? Cromwell D. Enage

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[signals2] trunk - vc++ 10 warning about assignment operator
by Edward Diener 13 May '11

13 May '11

An attempt to instantiate a signals2 signal of the form: template <class T> class notification_boost_signal2 { public: boost::signals2::signal<void (const i_some_interface<T> &,boost::optional<T>,T)> sig; }; for notification_boost_signal2<char>, gives the error message in vc++ of: "C:\Programming\VersionControl\boost\boost/signals2/detail/signal_template.hpp(367) : warning C4512: 'boost::signals2::detail::signal3_impl<R,T1,T2,T3,Combiner,Group,GroupCompare,SlotFunction,ExtendedSlotFunction,Mutex>::slot_invoker' : assignment operator could not be generated" There is a huge template trace leading up to this final warning, but before giving it I wonder if anyone knows what it is about ? Perhaps Frank Mori Hess or Douglas Gregor is out there and can tell me what is happening.

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[Block Pointer] multithread help
by Phil Bouchard 13 May '11

13 May '11

Hi everybody, I was wondering if there is anybody familiar enough with Block Pointer that could give me a hand regarding multithread support. Once again the test file is at: https://svn.boost.org/svn/boost/sandbox/block_ptr/libs/smart_ptr/example/th… The main class I am trying to protect with a mutex is block_header from: https://svn.boost.org/svn/boost/sandbox/block_ptr/boost/block_ptr.hpp Thanks, -Phil

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[multi_array] Is there interest for an [index_list] library?
by Pierre-Andre Noel 13 May '11

13 May '11

(This email has earlier been sent to the wrong list. Thanks to Steven Watanabe for pointing that out.) Dear all, I would like to gauge the interest of the community in a library that can serve 1) as a complement to Boost.MultiArray and 2) as an alternative to Boost.MultiArray. For the first type of use, an example of the candidate library's capabilities is that it makes available a special iterator "it" that allows to browse all the elements of a MultiArray "m". This special iterator has an it.indices() members that returns a "list" Collection of indices (i.e. an IndexList) such that "m(list)" and "*it" are the same elements. This can be useful for functions whose effect on an element of "m" depends on where this element is situated in "m". The second way to use the candidate library is as an alternative to Boost.MultiArray of dynamically chosen (execution time) dimensionality. Moreover, the elements do not necessarily need to be arranged in a multi-dimensional "box", as is the case in a MultiArray. For example, a "simplex" organization of the elements is already implemented. If you are interested to know more, I strongly suggest you to take a look at the example file in sandbox/index_list/libs/index_list/examples.cpp . The library itself is in sandbox/index_list/boost and a readme file (with some details concerning concepts and "priorities") is in sandbox/index_list/libs/README . An automatically generated (Doxygen) documentation is located in sandbox/index_list/libs/index_list/doc/index.html . Sadly, there is no "real" documentation for now. Many thanks for your time. Sincerely, Pierre-André Noël

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boost lib must provide C interface?!
by Oliver Kowalke 13 May '11

13 May '11

Hi, can a boost C++ library be required/forced to provide a C API? Even if the library author doesn't like this idea - because he would be responsible for C stuff. <boost/config.hpp> include <cstddef> which will not be available for a C compiler - maybe this is an indication that boost libs are not required to implement a C-API. regards, Oliver -- Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de

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Testing Problems
by Christopher Jefferson 13 May '11

13 May '11

Apologises, the following message is going to be a fairly long list of complaints. However, I wanted to post them rather than just let them disappear. Some background: I previously worked on getting clang and libc++ working in boost, in both c++03 and c++0x mode, submitting a large number of patches to achieve that goal. I also ran regression testers for this libraries. I am broadly planning on giving that up, unless various things improve in various ways. That isn't a threat, just I don't have the man and CPU time to spare working around issues in boost. Problems: 1) Running the boost regression tests takes unacceptably long. I would like to run tests for clang with and without libc++, with and without c++0x mode. Running those 4 sets of tests takes a huge amount of time. Various tests (and I keep meaning to try to find which ones) take huge amounts of memory, meaning it isn't reasonable to run even a single-threaded boost regression test in the background on a 4GB machine. Running tests in parallel doesn't seem to speed them up particularly, while bringing the machine even more onto it's knees. 2) The boost regression testpage ( http://www.boost.org/development/tests/trunk/developer/summary.html ) is fairly useless, as it doesn't say when a particular test failed. This means I just have to try to memorise the current state of all the compilers I am interested in, and look for new fails by eyeball. Much more useful would be changing the 'fail' to the most recent svn version at which a new fail occurred? 3) I always find trac hard to use. I usually want to do 2 things: a) Find all open bugs attached to package X b) List all bugs which I filed, or have have submitted a message to. I find both of these easy to achieve with bugzilla, and not with trac. 4) Getting patches, in particular very simple ones (like warning suppression) can take multiple prods and can languish for a long time in trac. I'm not sure what the best solutions to all of these problems are. Obviously they could each be tackled but several of them would involve changes to many different boost libraries, which is something I find can be like pulling teeth (some maintainers are extremely good, I certainly don't want to tar everyone with one brush!) On practical note, is it time for boost to move to officially supported compilers for each release? These could easily be read off the testing page (no test = not offically supported), and the packages which do not pass testing could be briefly listed in the release notes. This might have the advantage of encouraging more people to run tests, if they want their compiler to be offically supported. Apologises for the lengthy rant, Chris Jefferson

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