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[voronoi]medial axis
by Louis Lavery 19 Sep '13

19 Sep '13

[mods: I posted this a few days ago, and that post was acknowledged etc (it was my first post as a new subscriber) but I haven't receieved a copy myself and cannot find it in the archives - perhaps I should be more patient?] Hello, I'm hoping to use boost voronoi to construct the (internal) medial axis for closed shapes (with holes). I need to work out which vertices of the voronoi are inside, outside and on a boundary. So my first goal is to determine which vertices correspond to the ends of the input segments (boundary vertices). The way I do this at the moment, is to look at each edge and test if its source vertex, vertex0(), is equal to either end point of the segment contained by the edge's cell. (1) If it is then it's a boundary vertex otherwise it's not. Is that correct? (2) When comparing a vertex with an input point can I do an exact compare (==) or should I use a tolerance (epsilon)? Thanks, fuzzy.

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[cpo-proposal] About mixout container for polymorphic objects
by Santiago Tapia 17 Sep '13

17 Sep '13

Hi all, I have design a new concept of container to be part of the cpo library. In summary, those containers will break down the inserted objects into some elementary parts. Why do that? Short answer: to save memory. Long answer: Because the alignment requirement of data members in an object could be very different, in a range from 1 byte to 16 bytes, structs or classes use padding to provide the correct location for members. That means an object size could be significantly greater than the sum of its members sizes. Even more, when dealing with polymorphic objects, the size is increased a little more due to the pointer to the table of virtual methods. I will try to outline the alternative solution, obviously, the implementation will be part of the container, the user will not need to know the details. ---- Example:----- #include <cstdlib> #include <iostream> #include <vector> class output { public: virtual void print(std::ostream& out) = 0; }; class integer { public: integer(short a_ = 0) : a(a_) { } short a; }; class character { public: character(char c_ = 'a') : c(c_) { } char c; }; class data { public: data(double x_ = 0) : x(x_) { } double x; }; class my_object : public integer, public data, public character, public output { public: my_object(int show = 1) : integer(rand() % 100) , data(1.0*rand()/RAND_MAX) , character('a' + rand() % 10) { if (show) print(std::cout); } virtual void print(std::ostream& out) { std::cout << a << "\t" << x << " \t" << c << "\n"; } }; void insert( std::vector<integer>& v_int, std::vector<data>& v_data, std::vector<character>& v_char, const my_object& o) { v_int.push_back( o ); v_data.push_back( o ); v_char.push_back( o ); } void iterate( std::vector<integer>& v_int, std::vector<data>& v_data, std::vector<character>& v_char ) { my_object o(0); unsigned i; for ( i = 0; i < v_int.size(); ++i) { static_cast<integer&>( o ) = v_int[i]; static_cast<data&>( o ) = v_data[i]; static_cast<character&>( o ) = v_char[i]; o.print(std::cout); } } int main(int, char**) { std::cout << "sizeof(my_object): " << sizeof(my_object) << "\n"; std::vector<integer> v_int; std::vector<data> v_data; std::vector<character> v_char; std::cout << "--- inserting (random) objects ---\n"; unsigned i; for ( i = 0; i < 5; ++ i ) { insert( v_int, v_data, v_char, my_object() ); } std::cout << "--- show content ---\n"; iterate(v_int, v_data, v_char); return 0; } ---- Output: (32 bit PC) ---- sizeof(my_object): 20 --- inserting (random) objects --- 83 0.394383 h 15 0.911647 f 86 0.76823 j 21 0.477397 h 90 0.513401 d --- show content --- 83 0.394383 h 15 0.911647 f 86 0.76823 j 21 0.477397 h 90 0.513401 d Final comment. In this example, all the std::vector objects will be part of the mixout container. The user will only use the insert method and the container iterator that will dereference to output& (template parameter in the container). Just in this simple example the implementation saves aproximately n* (20 - (8+2+1) = 9) bytes, being n the number of instances of my_object. Comments are wellcome. Best regards, Santiago Tapia

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[svn] pre-commit hook/mime-type
by Tim Blechmann 17 Sep '13

17 Sep '13

hi all, is it possible that the pre-commit hook had changed recently? not sure if this was intended, but it currently breaks the use of git-svn, which imo is a huge inconvenience: -- tim@moka-mac:~/Documents/boost-trunk-git/boost$ git svn dcommit Committing to https://svn.boost.org/svn/boost/trunk ... A boost/sync/detail/generic/event_cv_emulation.hpp A boost/sync/detail/windows/event.hpp A boost/sync/event.hpp A libs/sync/test/event_test.cpp ERROR from SVN: A repository hook failed: Commit blocked by pre-commit hook (exit code 1) with output: /home/subversion/boost/hooks/check-mime-type.pl: trunk/boost/sync/detail/generic/event_cv_emulation.hpp : svn:mime-type is not set trunk/boost/sync/detail/windows/event.hpp : svn:mime-type is not set trunk/boost/sync/event.hpp : svn:mime-type is not set trunk/libs/sync/test/event_test.cpp : svn:mime-type is not set Every added file must have the svn:mime-type property set. In addition text files must have the svn:eol-style property set. For binary files try running svn propset svn:mime-type application/octet-stream path/of/file For text files try svn propset svn:mime-type text/plain path/of/file svn propset svn:eol-style native path/of/file You may want to consider uncommenting the auto-props section in your ~/.subversion/config file. Read the Subversion book (http://svnbook.red-bean.com/) Chapter 7, Properties section, Automatic Property Setting subsection for more help. Also, see http://svn.boost.org/trac/boost/wiki/BoostSubversion W: b7ab541813d43b7d74b44f57eb04c2625ce305a7 and refs/remotes/git-svn differ, using rebase: :040000 040000 4b2ab78eaa8f1e5fa80761a327da5066ca15d465 73aa096ac4b16618132d6d012e964b1790542c8f M boost :040000 040000 6146f06c45f590b38f76d123656cea13f24471d1 7a95e843ffc2f67fff874b6bd6c142b040423414 M libs Current branch master is up to date. ERROR: Not all changes have been committed into SVN, however the committed ones (if any) seem to be successfully integrated into the working tree. Please see the above messages for details. -- this used to work fine just a few days ago. was this done intentionally? if so, an announcement on the list with a comment on the implications for the git-svn users would have been good to see. best, tim

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[functional] New functor adaptors
by Tigran Hayrapetyan 17 Sep '13

17 Sep '13

Hello, Suppose we want to transform sequence of integers by doubling and adding 5 to each value (x = 2*x + 5 for all x in sequence). If using std::transform, then we need a functor which will for given "x" return "2*x + 5". My question is - is it possible to do it in C++98 style (without lambda expressions), and without writing additional functor class? As I understand, it's not. For doing that we need something like nesting functors into each other. Here we have "std::bind2nd( std::multiplies<int>(), 2 )" functor, and "std::bind2nd( std::plus<int>(), 5 )" functor, which must be nested to provide necessary functionality. I suggest something like "unary_result_translator" functor adapter, which is unary functor itself, and which will apply unary functor to result of another unary functor. The implementation of "unary_result_translator" can be something like this: template< typename Fn1, typename FnTrans > class unary_result_translator { public: typedef typename Fn1::argument_type argument_type; typedef typename FnTrans::result_type result_type; unary_result_translator( const Fn1& fn1, const FnTrans& fn_trans ) : fn1_( fn1 ), fn_trans_( fn_trans ) {} result_type operator()( const argument_type& arg ) const { return fn_trans_( fn1_( arg ) ); } const Fn1& fn1_; const FnTrans& fn_trans_; }; So, we will create our needed functor which converts "x" to "2*x + 5" by this: make_unary_result_translator( std::bind2nd( std::multiplies<int>(), 2 ), std::bind2nd( std::plus<int>(), 5 ) ) Of'course, unary_result_translator can be also used for more complex functors construction. Recently I used it for case-insensitive comparision of strings only with help of ::tolower. Similarly, there can be "binary_result_translator" which is binary functor itself, and which will apply unary functor to result of binary functor. Can that functor adaptors be useful? Or may be there is another way to do such things? Thanks for reading! Best Regards, Tigran Hayrapetyan

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Boost::lexical_cast<> under llvm 3.4
by Robert J Goedman 17 Sep '13

17 Sep '13

Hi, Has anyone tried boost::lexical_cast<> on clang++ based on llvm/clang++ 3.4? Or is it too early to use 3.4? Couldn't find any recent references to problems with lexical_cast (except from Mar 16, 2013 and older, but boost_1_54_0 does have that fix in it). No problems with llvm/clang++ 3.3, but on a test machine under 3.4 it produces the errors shown in below file lexical_cast-error.txt. The files are also at https://github.com/goedman/clang11-spirit-qi , in the Boost_lexical_cast directory. As far as I can see, all other parts of a spirit::qi project does build, the error occurs in a small print utility where lexical_cast<> is used.. Rob J. Goedman goedman(a)icloud.com

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Re: [boost] [threads] Memory leaks in Boost threading support? Version boost_1_53_0
by Vicente J. Botet Escriba 16 Sep '13

16 Sep '13

Le 15/09/13 16:58, Paul Morrison a écrit : > Hi Vicente, > > I got your note about the memory leak not being connected to > condition_variable, but this one seems to be... see png file attached... > > Any suggestions you may have would be appreciated! > > TIA > > Paul M. > > PS I wasn't sure how to make sure that my reply got back to you in > person! :-) No, what I mean is that my comment had nothing to be with the condition_variable memory_leak. Unfortunately, I have not found yet what could be the cause. If you can post a short example that reproduce the issue this would surely help. Best, Vicente

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[C++11] If you have an old class with a throwing destructor...
by Daryle Walker 16 Sep '13

16 Sep '13

I just got reminded of a breaking change in C++11 regarding this. Destructors without any exception specification in C++11 get `noexcept(true)` added to them. This means that pre-C++11 classes with throwing destructors turn into `std::terminate` bombs when imported to a C++11 project! I have two^H^H^Hthree such classes in Boost, so I just reported myself. (It's bug #9088, if you're curious.) Any other maintainers as stu^H^H^Henlightened as me should review their classes and add `noexcept(false)` when compiling in C++11 mode. If there are other libraries affected, maybe someone should make an en-masse bug ticket. Daryle W.

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[units] problems
by Robert Ramey 16 Sep '13

16 Sep '13

I want and need the boost.units functionality. I'm sure that this is what I want. But I've spend a lot of time going through the documentation and I'm having real difficulties figure out how to use this. There's a lot there so I feel that what I want must be in there somewhere. I've started going through the tutorial example and there are a couple of problems. First of all, it doesn't compile on my machine. Looking at the tutorial, it actually contains two programs - one of which is commented out. I tried the commented out one as well - it didn't compile either. Note that other than in the header, there are very few if any comments in this code. It doesn't qualify as a tutorial. What I expect to see is: #include <boost/units/quantity.hpp> #include <boost/units/systems/si/length.hpp> #include <boost/units/base_units/us/mile.hpp> void main(){ using namespace boost::units; using namespace boost::units::si; using namespace boost::units::us; quantity<length, float> l1; l1 = 1000.0 * meters; quantity<length, float> l2; l2 = 1.0 * miles; // compile error quantity<length, float> l3 = l1 + l2; } and I expect this to pretty much work. The documentation says " Implicit conversions between unit systems are allowed only when the reduced units are identical, allowing, for example, trivial conversions between equivalent units in different systems (such as SI seconds and CGS seconds)" so I expected that it can convert miles into kilometers. This is a disappointment - but I'll assume that the authors have a good reason for this. So I'm interest in figuring out how to fix this but the manual doesn't seem to help me. I know a huge amount of effort has been invested in this package, but I'm afraid this issue of documentation is a big obstacle to this package being used every where it could be. Note to authors of boost libraries. When you think you've got the documentation done, hand it to someone who isn't familiar with it and ask him to make a small example using the library in 30 minutes. If he can't do that, it's time to go back to work. Most users will give up if they can't get some sort of love back from the library in that amount of time. Robert Ramey

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Re: [boost] [threads] Memory leaks in Boost threading support? Version boost_1_53_0
by Paul Morrison 16 Sep '13

16 Sep '13

>> Hi Vicente, >> >> I got your note about the memory leak not being connected to >> condition_variable, but this one seems to be... see png file >> attached... >> >> Any suggestions you may have would be appreciated! >> >> TIA >> >> Paul M. >> >> PS I wasn't sure how to make sure that my reply got back to you in >> person! :-) > PPS having trouble reducing size of attachment - hope you can read it!

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[threads] Memory leaks in Boost threading support? Version boost_1_53_0
by Paul Morrison 14 Sep '13

14 Sep '13

I am running a number of Boost threads communicating via bounded buffers. My programs seem to run properly, but I get a number of memory leaks, usually 4- and 8- byte areas, although a few are longer. As far as I can tell, they are coming from inside Boost, as there is no mention of lines in my code. OTOH, although my code runs fine, it is quite possible that there are subtle errors in it! I am using _CRTDBG_MAP_ALLOC, which is being used correctly as it detected one area of my own that I was not freeing up, and that has been fixed. I am running VC++ 2010 Express on a 64-bit machine. Here is my memory leak display - I tried setting a few of the numbers as breakpoints, using_CrtSetBreakAlloc(), but most of them did not cause breaks. The first one broke at a new in > boost::detail::basic_condition_variable::get_wait_entry() Line 180 + 0x7 bytes C++ Why wouldn't this get freed up?! Note: <bad exception > looks ominous - where is it coming from?! Detected memory leaks! Dumping objects -> {8624} normal block at 0x02312550, 4 bytes long. Data: <HC1 > 48 43 31 02 {8615} normal block at 0x0015F8F8, 4 bytes long. Data: <h!1 > 68 21 31 02 {8602} normal block at 0x023117A0, 4 bytes long. Data: < 51 > F8 35 31 02 {5584} normal block at 0x02311760, 4 bytes long. Data: <@ > 40 F7 15 00 {4013} normal block at 0x0015F948, 4 bytes long. Data: < 1 > 00 17 31 02 {3924} normal block at 0x02314048, 4 bytes long. Data: < <1 > 20 3C 31 02 {3883} normal block at 0x02314008, 4 bytes long. Data: < +1 > D0 2B 31 02 {3862} normal block at 0x02313CA0, 4 bytes long. Data: <h!1 > 68 21 31 02 {445} normal block at 0x02314088, 4 bytes long. Data: < R1 > 88 52 31 02 {440} normal block at 0x023145F8, 4 bytes long. Data: <HC1 > 48 43 31 02 {430} normal block at 0x02314648, 4 bytes long. Data: < 51 > F8 35 31 02 {402} normal block at 0x02313FC0, 4 bytes long. Data: < 1 > 98 1D 31 02 {395} normal block at 0x023136B8, 4 bytes long. Data: < +1 > D0 2B 31 02 {382} normal block at 0x02313A18, 4 bytes long. Data: < 51 > F8 35 31 02 {355} normal block at 0x02312B90, 4 bytes long. Data: <HC1 > 48 43 31 02 {332} normal block at 0x023121E8, 4 bytes long. Data: <h > 68 F8 15 00 {316} normal block at 0x02311978, 4 bytes long. Data: <HC1 > 48 43 31 02 {298} normal block at 0x023117E0, 4 bytes long. Data: < 51 > F8 35 31 02 {270} normal block at 0x023106D0, 4 bytes long. Data: < 1 > E0 0E 31 02 {256} normal block at 0x02310C50, 4 bytes long. Data: < R1 > 88 52 31 02 {225} normal block at 0x0015FC30, 4 bytes long. Data: < > 90 F9 15 00 {217} normal block at 0x0015F5C0, 8 bytes long. Data: <l > 6C F5 15 00 00 00 00 00 {213} normal block at 0x0015E7B8, 8 bytes long. Data: < > 14 E7 15 00 00 00 00 00 {212} normal block at 0x0015E770, 8 bytes long. Data: < > EC E6 15 00 00 00 00 00 {208} normal block at 0x0015D900, 8 bytes long. Data: <\ > 5C D8 15 00 00 00 00 00 {207} normal block at 0x0015D8B8, 8 bytes long. Data: <4 > 34 D8 15 00 00 00 00 00 {203} normal block at 0x0015CA48, 8 bytes long. Data: < > A4 C9 15 00 00 00 00 00 {202} normal block at 0x0015CA00, 8 bytes long. Data: <| > 7C C9 15 00 00 00 00 00 {198} normal block at 0x0015BB90, 8 bytes long. Data: < > EC BA 15 00 00 00 00 00 {197} normal block at 0x0015BB48, 8 bytes long. Data: < > C4 BA 15 00 00 00 00 00 {193} normal block at 0x0015ACD8, 8 bytes long. Data: <4 > 34 AC 15 00 00 00 00 00 {192} normal block at 0x0015AC90, 8 bytes long. Data: < > 0C AC 15 00 00 00 00 00 {188} normal block at 0x00159E20, 8 bytes long. Data: <| > 7C 9D 15 00 00 00 00 00 {187} normal block at 0x00159DD8, 8 bytes long. Data: <T > 54 9D 15 00 00 00 00 00 {183} normal block at 0x00158F68, 8 bytes long. Data: < > C4 8E 15 00 00 00 00 00 {182} normal block at 0x00158F20, 8 bytes long. Data: < > 9C 8E 15 00 00 00 00 00 {178} normal block at 0x001580B0, 8 bytes long. Data: < > 0C 80 15 00 00 00 00 00 {177} normal block at 0x00158068, 8 bytes long. Data: < > E4 7F 15 00 00 00 00 00 {173} normal block at 0x001571F8, 8 bytes long. Data: <Tq > 54 71 15 00 00 00 00 00 {172} normal block at 0x001571B0, 8 bytes long. Data: <,q > 2C 71 15 00 00 00 00 00 {168} normal block at 0x00156340, 8 bytes long. Data: < b > 9C 62 15 00 00 00 00 00 {167} normal block at 0x001562F8, 8 bytes long. Data: <tb > 74 62 15 00 00 00 00 00 {164} normal block at 0x00155B30, 8 bytes long. Data: < Z > D4 5A 15 00 00 00 00 00 {162} normal block at 0x001559E0, 8 bytes long. Data: < Y > 84 59 15 00 00 00 00 00 {160} normal block at 0x00155890, 8 bytes long. Data: <4X > 34 58 15 00 00 00 00 00 {158} normal block at 0x00155740, 8 bytes long. Data: < V > E4 56 15 00 00 00 00 00 {156} normal block at 0x001555F0, 8 bytes long. Data: < U > 94 55 15 00 00 00 00 00 {154} normal block at 0x001554A0, 8 bytes long. Data: <DT > 44 54 15 00 00 00 00 00 {152} normal block at 0x00155350, 8 bytes long. Data: < R > F4 52 15 00 00 00 00 00 {150} normal block at 0x00155200, 8 bytes long. Data: < Q > A4 51 15 00 00 00 00 00 {148} normal block at 0x001550B0, 8 bytes long. Data: <TP > 54 50 15 00 00 00 00 00 {146} normal block at 0x00154F60, 8 bytes long. Data: < O > 04 4F 15 00 00 00 00 00 {144} normal block at 0x00154E10, 8 bytes long. Data: < M > B4 4D 15 00 00 00 00 00 {140} normal block at 0x00154C40, 16 bytes long. Data: < K > 0C 1D EF 00 02 00 00 00 01 00 00 00 88 4B 15 00 {139} normal block at 0x00154BF0, 14 bytes long. Data: <bad exception > 62 61 64 20 65 78 63 65 70 74 69 6F 6E 00 {138} normal block at 0x00154B88, 44 bytes long. Data: < h > F4 1C EF 00 00 00 00 00 68 F8 EE 00 18 F8 EE 00 {135} normal block at 0x00154A98, 16 bytes long. Data: <\ 0J > 5C 1C EF 00 02 00 00 00 01 00 00 00 30 4A 15 00 {134} normal block at 0x00154A30, 44 bytes long. Data: <D 8 > 44 1C EF 00 00 00 00 00 88 F7 EE 00 38 F7 EE 00 Object dump complete.

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Forking boost's git
by Mathias Gaunard 13 Sep '13

13 Sep '13

Hi, I would have liked to fork Boost to maintain my own version with my patches before they get merged in master. I was considering using git for this, unfortunately I don't know how to make this happen with submodules. Do I need to fork each submodule separately and to edit the .gitmodules file? Is there a way to not have to do that by hand?

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[COUNTERTREE + SUBALLOCATOR ] version 2.0
by Francisco José Tapia 13 Sep '13

13 Sep '13

Hi this message is to announce the version 2.0 of the *[countertree + suballocator]* library. 1 year ago I presented the request for the evaluation of the [countertree+ suballocator] version 1.0. The approval process is stopped due to the absence of review managers, and in the meanwhile I continued with the develop of this version 2.0. Actually the most important libraries and environments for parallel development, *don't provide parallel algorithms for th**e** data structures based on trees* ( set , multiset, map and multimap), and all the operations with these data structures are done with 1 thread. This is due to the difficult to divide the element of the tree between an arbitrary number of threads. (If you want to access to the element in the position 1000, you must go sequentially forward from the position 0 or sequentially backward from the last position. The [countertree + suballocator] library provide data structures set, multiset,map and multimap compatibles with the STL data structures *plus the access to the elements by their position like in a vector, and random access iterators*, You can manage it like a vector. Many parallel algorithms designed for vectors, can be used without changes with the countertree data structures. This make *easy **the **design **of **parallel algorithms* for these data structures. In the library there are a concurrent and a non concurrent versions of all the data structures. The non concurrent version are designed for to be executed inside 1 thread, or for to be accessed by several threads only in read operations (like the STL data structures), they provide a bit more speed than the concurrent version. The concurrent version is *thread safe with all the operations*, one thread can be read and other writing over the same data structure in a safe mode ( as you can see in 2.3 -examples) The concurrent library provide the full set of functions of the STL , plus an *additional set of functions*. These functions have the mission of resolve the problems appeared in the concurrent development. By example, you have a map, find an iterator from a key and with the iterator modify the element, but in the middle, other thread delete the element, and when try to access with the iterator, the program crash, and it is very difficult to reproduce the error for to debug. These additional functions make a pack with the two things, first with a read lock which permit concurrent reads, and when obtain the iterator with an exclusive lock for to modify. These additional functions *prevent the problems* like the previously described, with an *easy interface* for to understand and use for the final user. I don't know if exist any other library with tree based structures with random access iterators. I had search for and didn't find. If someone knows someone, please, say me, I am interested to know something new and collect good ideas. I suppose it don't exist because i didn't see parallel support for data structures based on trees, in any library or parallel tools. I request help to the Boost community because I am in the *moment “perhaps” *. Perhaps I forgot something, perhaps something is wrong, perhaps someone decision was not correct, perhaps it can be done in other way... *Please*, is someone see any fail, any omission, any alternative or simply any comment, please say me, in order to reach the final objective, *provide to the C++ community a good, fast, robust and reliable tool.* In my opinion, this library or other with similar functionality, is the last big part needed for to begin to think about a *concurrent STL* . You can find concurrent libraries with vectors and arrays. You have too, concurrent libraries with containers based on hash functions. With the countertree library you have concurrent set, multiset,map and multimap. The concurrent linked list can be implemented with the concurrent vector_tree ( other data structure of the library). The concurrent STL is a very big project, and must involve many agents and perspectives. From the users associations, to big computers makers and big data providers, passing by the compiler makers, the parallel tools providers... But I am sure the *Boost community* will play a central role by prestige, knowledge and experience designing libraries You can find the documentation and the code in the GitHub https://github.com/fjtapia/countertree_2.0 or you can see online in my dropbox page : https://dl.dropboxusercontent.com/u/8437476/works/countertree_2.0/index.html<https://dl.dropboxusercontent.com/u/8437476/works/countertree_2.0/doc/index…> If you prefer download a file with all the code and the documentation : https://github.com/fjtapia/countertree_2.0/blob/master/doc/countertree_2.0.… Sincerely yours Francisco Tapia fjtapia(a)gmail.com ** I you don't try the library, perhaps the most interested parts of the documentation is the 1.5.- Next improvements. Where explain the future parallel algorithms for the library and how they can improve others areas of the computation with the augmented trees.*

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Some patches to remove obsolete MSVC version checks
by Stephen Kelly 13 Sep '13

13 Sep '13

Hi, I've created patches to remove or simplify some ifdefs for MSVC versions which are now obsolete. There are many more to do. http://www.steveire.com/msvc_obsolete_versions_patches This is a followup to this thread: http://thread.gmane.org/gmane.comp.lib.boost.devel/243094 (Removing old config macro and increasing compiler requirements., 2013-07-29) The patches are most easily applied locally and reviewed with a git-svn checkout and git am. I'll also apply to get SVN access so I can commit patches myself. Thanks, Steve.

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[asio] boost::asio::async_connect reports success on failure
by Ben Pope 13 Sep '13

13 Sep '13

Hi all, I've found a regression between 1.53 to 1.54; if you compile boost/libs/asio/example/cpp11/chat/chat_client.cpp and point it at a host and port that doesn't exist or refuses the connection, instead of coming back with an error, such as host not found or connection refused, it reports success (on the conversion to bool). (you might want to embellish the example with a std::cout << error_code.message() << std::endl;) This appears to be the case across Linux, Darwin, iOS and Android :( synchronous connect seems to work correctly (i.e., echo/blocking_tcp_echo_client.cpp) Ben

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Removing old config macro and increasing compiler requirements.
by Stephen Kelly 12 Sep '13

12 Sep '13

Hi there, I've been working on the modularization effort from a CMake point of view, and from an 'actual modularization' point of view, looking at interdependencies: http://thread.gmane.org/gmane.comp.programming.tools.ryppl.devel/9/focus=26 I'd like to start on reducing interdependencies, and I'd like to start reasonably small, as no-one in the boost community knows me and see how it goes from there. I'm very active in CMake, Qt and KDE. Currently, in the modularized boost repos, boost::config and boost::core depend on each other. I listed 3 ways of fixing this on the ryppl list: http://thread.gmane.org/gmane.comp.programming.tools.ryppl.devel/201 My preference is the removal of BOOST_NO_EXPLICIT_FUNCTION_TEMPLATE_ARGUMENTS, and requiring compilers to have the feature. That way boost/config/suffix.hpp will no longer need to include boost/{non_,}type.hpp. My preference is increasing the compiler requirement, because that may open up more similar opportunities for reducing dependencies and interdependencies throughout boost. Grepping indicates that that means increasing the compiler requirements to something like __DMC__ > 0x840, GCC > 3.2, BOOST_INTEL_CXX_VERSION > 500, VC++ > 7.0. Comments? Thanks, Steve.

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proposal for metafunction mpl::eval
by klaus triendl 12 Sep '13

12 Sep '13

Hi, I'm not so much into meta-programming, so I'm not sure whether there's already an alternative available. Nevertheless I'd like to propose a new metafunction that simply evaluates its argument: template<typename F> struct eval: F::type {}; I've found it somehow useful because it avoids syntactical sugar when specifying a condition to be evaluated for eval_if: eval_if< eval<apply<UnaryF, Arg>>, F1, F2 >; instead of writing: eval_if< typename apply<UnaryF, Arg>::type, F1, F2 >; Any comments on this? -- klaus triendl

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[interprocess] Different processes accessing shared memory in different locations
by Tom Sanham 11 Sep '13

11 Sep '13

Hi Our application has the following scenario using Boost V1.0.52: 1) Process A writes to boost interprocess shared memory. The files appear at C:\ProgramData\boost_interprocess\... 2) Process A launches Process B 3) Process B attempts to read from shared memory but fails. It is attempting to read from: C:\Users\<username>\AppData\Local\Temp\boost_interprocess\... This failure only occurs on one single Windows 8 64 bit machine out of many we have tested. On all other machines, the application works perfectly. Please could somebody advise: What changes to our application could be made to avoid this? What changes to the machine's configuration (eg. Registry) could be made to avoid this issue? Many thanks Thomas Sanham

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[asio] Mixing streambuf-based async_read and async_read_until
by Gavin Lambert 11 Sep '13

11 Sep '13

I was tracing through some code today (using Boost.Asio 1.53) and noticed something that seems a little odd to me. Given a boost::asio::streambuf that already contains data (typically from a previous read), the async_read_until operation will check the buffer first to see if it can find the specified delimiter already, and will only fetch more data from the stream if it needs to. It does appear to perform at least one async_read_some per async_read_until call, but this will be a zero-length-read that will not actually hit the network/wherever. (Could probably be optimised a little further though.) The async_read operation however will not check the buffer. While it won't destroy any existing data (it just appends) it will still fetch additional data from the stream up to the specified completion condition, ignoring however much is already in the buffer. For example, if buf already contains 32 unconsumed bytes then async_read(s, buf, transfer_exactly(16), cb) will fetch 16 more bytes from the network, leaving 48 bytes in the buffer but only passing 16 to the read handler. Of particular note is that it will wait for those 16 bytes to be read from the network -- it's not satisfied with the data it already has. The net effect of these behaviours I think is that if you're using async_read_until exclusively or async_read exclusively then everything will behave fairly normally. If you are mixing these two operations on the same stream then you will either be losing data (if you use separate streambufs) or reading more data than you should (if you use the same streambuf and don't check outside of ASIO to see if it already contained enough data). Maybe it's just me, but I find it surprising that async_read doesn't check if the supplied streambuf already satisfies the completion condition, given that async_read_until does and the docs for async_read do say that it's allowed to make zero async_read_some calls. Is this a bug or is it expected behaviour?

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Incompatible Boost license file in boost.container
by Philip Bennefall 10 Sep '13

10 Sep '13

Hi all, I was looking at boost.container, and found that boost/container/deque.hpp has similar problems as boost/detail/endian.hpp had before that was fixed. Parts of deque.hpp seem to be covered by a license that is not compatible with the Boost software license. I quote: // Copyright (c) 1996,1997 // Silicon Graphics Computer Systems, Inc. // // Permission to use, copy, modify, distribute and sell this software // and its documentation for any purpose is hereby granted without fee, // provided that the above copyright notice appear in all copies and // that both that copyright notice and this permission notice appear // in supporting documentation. Etc. Kind regards, Philip Bennefall

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Re: [boost] [cpo-proposal] presentation of the idea
by Santiago Tapia 10 Sep '13

10 Sep '13

Hi, I have working in the implementation of the cpo library, so I keep working and I expect to make a formal proposal within 2 or 3 months, and meanwhile I will try my best to answer mails. > Date: Wed, 28 Aug 2013 11:18:03 +0400 > From: Andrey Semashev <andrey.semashev(a)gmail.com> > The storage strategy does not mandate the interface of the container. > unordered_set/map are implemented as a number of buckets (i.e. > single-linked lists), yet they provide sequence interface with an > additional ability to iterate within a single bucket. I don't see why a > similar approach couldn't be taken in your container. I will not provide the classifier container with a push_back or push_front method, instead I will use insert, I suppose it is just about the meaning of sequence, I expect a sequence to keep an order on items while container means just a collection of items in not a particular order. On the other hand I will provide a way to iterate over a "single bucket". Actually, I have been working on benchmarking and that seems to be the better option to iterate over the classifier because it reduces the number of virtual method calls in the iteration. I also will provide a const random access iterator and some other utilities to access a particular item in the container. > > You can't create std::multiset<shape> but you can create > boost::intrusive::multiset<shape>. The reason for that is that > std::multiset attempts to allocate storage for shape, while > boost::intrusive::multiset doesn't, leaving this to the user. This allows > you to insert any objects derived from shape to the single > boost::intrusive::multiset and work with this container pretty much the > same way you would with std::multiset. You can even insert the very same > object in multiple containers if you need to. I recommend you to have a > look at Boost.Intrusive, it is a truly amazing library. The interface for my library needs to be far more simple than the interface in Boost.Intrusive, but I will consider that option to implement the details. Up to now, I am only using std containers to avoid dependencies, but I will consider other options to optimize speed and size performance. [snip] About "polymorphic vector", that is, a container that stores different types contigously, I should say that the interface needs to be as easy as in the classifier, so I will discard solutions that needs any requirement to objects apart from being copyable, default constructive or the like. I will try to develop a prototype from Larry Evans' example (with his permission). But because I am not an expert on alignment and memory optimization, I will try to use something "more standard", actually I am going trying to use the allocator to compute the "right" address to place an object of a given type that is greater that a "free" memory pointer. In that way, I also expect to take advantages of allocator such as tbb cache aligned allocator. Again, thank you all for your comments. Regards, Santiago -- ESCUELA TÉCNICA SUPERIOR DE INGENIEROS INDUSTRIALES UNIVERSIDAD POLITÉCNICA DE MADRID Santiago Tapia Fernández | DEPARTAMENTO DE AUTOMÁTICA, INGENIERÍA ELECTRÓNICA E INFORMÁTICA INDUSTRIAL José Gutiérrez Abascal, 2 | 28006 Madrid TEL +34 91 336 4266 E-MAIL stapia(a)industriales.upm.es www.industriales.upm.es

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Re: [boost] [cpo-proposal] presentation of the idea
by Santiago Tapia 10 Sep '13

10 Sep '13

> Date: Mon, 09 Sep 2013 11:57:43 -0500 > From: Larry Evans <cppljevans(a)suddenlink.net> > >> But because I am not an expert on alignment and memory >> optimization, I will try to use something "more standard", actually I am >> going trying to use the allocator to compute the "right" address to place >> an object of a given type that is greater that a "free" memory pointer. >> In that way, I also expect to take advantages of allocator such as >> tbb cache aligned allocator. > > I know nothing about how 'to use the allocator to compute the "right" > address'; hence, I'm afraid I can't be any help there. Could you maybe > give a brief summary of how that works? > No idea, I was just speculating, actually, I am not sure I will be able to do it. On the other hand, I suppose there should be a way to do it. Just need some time and thought. > Best of luck on this project, Santiago! > > -regards, > Larry Thank you!

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[PREPROCESSOR] Possible improvement for BOOST_PP_VARIADIC_SIZE
by Brent Lewis 10 Sep '13

10 Sep '13

Currently, BOOST_VARIADIC_SIZE() evaluates to 1. Based on http://gustedt.wordpress.com/2010/06/08/detect-empty-macro-arguments/ it can be improved to return 0 for an empty argument list.

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Quid pro quo for Boost peer review manager
by Niall Douglas 09 Sep '13

09 Sep '13

Dear Boost Devs, GSoC 2013 ends on 23rd September, and myself and Paul expect that Boost.AFIO will be ready for peer review at around that time after finishing the following features from your voting at http://boostafio.uservoice.com/: (i) Directory Monitoring (ii) Asynchronous Directory Enumeration (iii) Parts of Improved formal closure execution engine support based on the latest updated papers in the Sept WG21 mailing N3721 and N3731. It seems unfair to ask for someone to volunteer to do all the work to be a review manager for AFIO without me volunteering to be a review manager for another Boost library in exchange, so I was wondering: are there any similar sized libraries to AFIO (~800 active LOC, ~20,000 for everything including docs and testing) which are ready for peer review and need a review manager? Thanks, Niall -- Currently unemployed and looking for work. Work Portfolio: http://careers.stackoverflow.com/nialldouglas/

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[Thread] possible bug in Move emulation "portable interface"
by Gavin Lambert 09 Sep '13

09 Sep '13

I tried submitting this via Trac but for some reason it was convinced that my bug report contained spam, while refusing to tell me what part it was objecting to, and also refusing to give me a captcha or anything to convince it otherwise. Anyways: Bug 1: the Boost.Thread documentation and release history indicate that BOOST_THREAD_VERSION==3 is the default since v1.52. As far as I can tell this has never been true in any released version; the latest code still has ==2. (I found a thread in boost-devel that was debating consequences of making breaking changes by default, which I assume is why this change was not actually made; but the docs need correcting.) Bug 2: when writing code using the Boost.Thread "Portable Interface" for move support/emulation, it recommends using the BOOST_THREAD_DCL_MOVABLE_BEG macro to "avoid conflicts with Boost.Move". However regardless of C++11 or not or the BOOST_THREAD_VERSION it defines a template specialisation in a way that assumes that it is called only from "namespace boost". As this usage is unlikely for any code outside the boost library itself, I think this is a bug. namespace user { template<typename T> class test { public: BOOST_THREAD_COPYABLE_AND_MOVABLE(test) test() {} test(const test&) {} test& operator=(BOOST_COPY_ASSIGN_REF(test) o) { return *this; } test(BOOST_THREAD_RV_REF(test) o) {} test& operator=(BOOST_THREAD_RV_REF(test) o) { return *this; } }; BOOST_THREAD_DCL_MOVABLE_BEG(T) test<T> BOOST_THREAD_DCL_MOVABLE_END } The above code will not compile. It does compile if the DCL define is moved into a "namespace boost" block, but I do not regard this as an acceptable solution. Suggested fix is to explicitly specify the namespace in the macro, eg. replace "enable_move_utility_emulation" with "::boost::enable_move_utility_emulation".

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Fwd: Re: [atomic] atomic<int>::is_lock_free() returns false on iPad 4 (armv7s)
by Tim Blechmann 09 Sep '13

09 Sep '13

-------- Original-Nachricht -------- Betreff: Re: [boost] [atomic] atomic<int>::is_lock_free() returns false on iPad 4 (armv7s) Datum: Mon, 09 Sep 2013 15:49:06 +0100 Von: Phil Endecott <spam_from_boost_dev(a)chezphil.org> An: Tim Blechmann <tim(a)klingt.org> Hi Tim, (My Boost list subscription is temporarily broken; feel free to forward this if you want.) Tim Blechmann wrote: >>> boost:atomic<int>::is_lock_free() returns false on iPad 4 (armv7s) but >>> returns true on iPad 3 (armv7). Yes. I thought this had been fixed. It's now too long ago for me to recall exactly what happened. I know that I filed a trac ticket to get it fixed in smart_ptr's spinlock; I think that at that time Boost.Atomic has still not been reviewed and merged, and I probably fixed it only in a local copy. > btw, it may be worth to note that on iOS devices std::atomic should be > available ... Absolutely! Few people have any reason to be using Boost.Atomic. Regards, Phil.

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