June 2012 - Boost-users - lists.preview.boost.org

Review Wizard Report for June 2012
by Ronald Garcia 18 Jun '12

18 Jun '12

============================================== Review Wizard Status Report for June 2012 ============================================== News ==== 1. Predef Library Reviewed 2. Boost 1.49.0 Released. New Library: Heaps 3. Multiprecision Arithmetic Review Ongoing Open Issues =========== The following libraries have been reviewed and await reports from their review managers: * Predef - reviewed February 2012; review manager: Joel Falcou. * Conversion - reviewed August 2011; review manager: Gordon Woodhull. The following libraries have been accepted to Boost, but have not yet been submitted to SVN: * Constrained Value - accepted September 2010; author: Robert Kawulak. * GIL.IO - accepted January 2011; author: Christian Henning. * Atomic - accepted July 2011; author Helge Bahmann. * Lockfree - accepted August 2011; author: Tim Blechmann. The following libraries have been accepted and submitted to SVN, but have not yet appeared in a release: * Type Traits Introspection - accepted August 2011; author: Edward Diener. * Context - accepted January 2012; author: Oliver Kowalke. The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * Endian - accepted provisionally November 2011; author: Beman Dawes. * Log - accepted provisionally March 2010; author: Andrey Semashev. General Announcements ===================== As always, we need experienced review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "rxg at cs dot cmu dot edu" and "phillips at pacific dot mps dot ohio-state dot edu" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report before we do that, please email Ron or John. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Review Schedule =============== * Join (M) * Pimpl (M) * Sorting (M) * Quaternions, Vectors, Matrices (M) * Variadic Macro Data (M) * Block Pointer (M) * Singularity (M) * Extended Complex Numbers (M) * Metaparse (M) * Polygon: Voronoi Extensions * Coroutine * Type Erasure * Range Extensions (M) * Contract * Nowide (M) ``(M)`` marks libraries that need review managers. -------------------- Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Pimpl ----- :Author: Vladimir Batov :Review Manager: Needed :Download: https://github.com/boost-vault/Miscellaneous/blob/master/Pimpl.zip :Description: The Pimpl idiom is a simple yet robust technique to minimize coupling via the separation of interface and implementation and then implementation hiding. This library provides a convenient yet flexible and generic deployment technique for the Pimpl idiom. It's seemingly complete and broadly applicable, yet minimal, simple and pleasant to use. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: https://github.com/boost-vault/Sorting :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 2X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 70% faster than std::sort. string_sort is roughly 2X as fast as std::sort. Quaternions, Vectors, Matrices ------------------------------ :Author: Emil Dotchevski :Review Manager: Needed :Download: http://www.revergestudios.com/boost-qvm/ :Description: QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Variadic Macro Data ------------------- :Author: Edward Diener :Review Manager: Needed :Download: `Boost Sandbox <http://svn.boost.org/svn/boost/sandbox/variadic_macro_data/>`__ :Description: This library adds support and functionality for variadic macros to Boost as well as integrating variadic macros with the Boost PP library without changing the latter library in any way. Block Pointer ------------- :Author: Phil Bouchard :Review Manager: Needed :Download: https://svn.boost.org/svn/boost/sandbox/block_ptr/ :Description: Deterministic memory manager of constant complexity capable of handling cyclic collections. Singularity ----------- :Author: Ben Robinson :Review Manager: Needed :Download: https://github.com/icaretaker/Singularity :Description: The Singularity Design Pattern allows you to restrict any class to a single instance. Unlike the infamous Singleton, Singularity gives you direct control over the lifetime of the object, does not require you to grant global access to the object, nor does it limit you to the default constructor for that object. Extended Complex Numbers ------------------------ :Author: Matthieu Schaller :Review Manager: Needed :Download: http://code.google.com/p/cpp-imaginary-numbers/ :Description: The library is an extension of the std::complex class addressing two issues: 1. The standard does not guaranty the behaviour of the complex class if instantiated with types other than float/double/long double. 2. Some calculation where pure imaginary numbers (i.e. multiples of sqrt(-1)) appear are unnecessarily slowed down due to the lack of support for these numbers. The code I submit contains two interleaved classes boost::complex and boost::imaginary which can be instantiated with any type T provided T overloads the usual arithmetic operators and some basic (real) mathematical functions depending on which complex function will be used. It is thus an extended version of Thorsten Ottosen's n1869 proposal (http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1869.html) Metaparse --------- :Author: Abel Sinkovics :Review Manager: Needed :Download: http://abel.web.elte.hu/metaparse/metaparse.zip :Description: Metaparse is a library for constructing parsers parsing at compile-time based on template metaprogramming. The parsers built with the library take boost::mpl::strings as input and can produce - types - objects (types with public static members) - callable C++ functions (types with public static method) - template metafunction classes as output (based on the input being parsed). On compilers supporting constexpr the library provides the following syntactic sugar for writing the input of the parsers: BOOST_STRING("this is a string") The library can be used for implementing DSLs in C++, including DSLs making C++ template metaprogramming easier (see examples). Polygon: Voronoi Extensions --------------------------- :Author: Andril Sydorchuk :Review Manager: Lucanus Simonson :Download: http://svn.boost.org/svn/boost/sandbox/gtl/ :Description: This library extends Boost.Polygon with the following features: - Robust and efficient implementation of the sweepline algorithm that allows to construct Voronoi diagram, Delaunay triangulation and medial axis of a set of points and line segments. - Coordinates of the output geometries are computed within the 64 machine epsilon relative error (6 mantissa bits). - Voronoi diagram data structure that allows efficient traversal and data association with the output Voronoi graph. - No 3rd party dependencies (e.g. GMP, MPFR), all the required multiple precision types are implemented as part of the library. - The input and output coordinate type domains are configurable via coordinate type traits, thus allowing to compute coordinates of the Voronoi vertices within any required precision. - The full construction of the Voronoi diagram of 100 000 points takes only 0.27 seconds (see benchmarks). Coroutine --------- :Author: Oliver Kowalke :Review Manager: Hartmut Kaiser :Download: http://gitorious.org/boost-dev/boost-dev/archive-tarball/coroutine :Description: This library is an implementation of coroutines and generators using Boost.Context. Type Erasure ------------ :Author: Steven Watanabe :Review Manager: Lorenzo Caminiti :Download: http://sourceforge.net/projects/steven-watanabe.u/files/ :Description: The TypeErasure library is a generalization of boost::any and boost::function. It allows easy composition of arbitrary type erased operators. Range Extensions ---------------- :Author: Akira Takahashi :Review Manager: Neil Groves :Download: https://github.com/faithandbrave/OvenToBoost :Description: This project adds some features of the Oven Range Library to Boost.Range. Features: - Additional Range Adaptors (taken, taken_while, dropped, dropped_while, elements, elements_key, memoized, outdirected) - Extensions for using Lambda (regular function, regular operator) - Infinite Range (iteration function) - and additional range utilities. Contract -------- :Author: Lorenzo Caminiti :Review Manager: Dave Abrahams :Download: http://sourceforge.net/projects/contractpp/files/latest/download :Description: This library implements Contract Programming for the C++ programming language (see the end of this email). In addition, the library implements virtual specifiers (final, override, and new, see C++11), concept checking, and named parameters. This library is implemented for the C++03 standard and it does not require C++11. Nowide ------ :Author: Artyom Beilis :Review Manager: Needed :Download: http://cppcms.com/files/nowide/ :Description: This library makes cross platform Unicode aware programming easier. It provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. Libraries under development =========================== See http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction for a current listing of libraries under development.

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(no subject)
by Chandan Nilange 17 Jun '12

17 Jun '12

http://brandnexus.com/wp-content/themes/themeforest_idealcorp-premium-busin…

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How to use shared_memory_object as a class member
by Achuth Sankar 17 Jun '12

17 Jun '12

Is there any way to use shared_memory_object as a class member ? regards Achuth

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boost 1.49.0 and boost.log
by Konstantin Ribel 16 Jun '12

16 Jun '12

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[boost] [review] Multiprecision review (June 8th - 17th, 2012)
by Jeffrey Lee Hellrung, Jr. 16 Jun '12

16 Jun '12

Okay, it's that time. Apologies for not sending a reminder, but there had been a lot of pre-review comments over the last week or so, so I think this has been on at least some people's radar. The original review announcement is given below. On Tue, May 29, 2012 at 2:08 PM, Jeffrey Lee Hellrung, Jr. < jeffrey.hellrung(a)gmail.com> wrote: > Hi all, > > The review of the proposed Boost.Multiprecision library authored by John > Maddock and Christopher Kormanyos has been scheduled for > > June 8th - June 17th, 2012 > > and will be managed by myself. > > From the Introduction: > > -------- > "The Multiprecision Library provides *User-defined* integer, rational and > floating-point C++ types which try to emulate as closely as practicable the > C++ built-in types, but provide for more range and precision. Depending > upon the number type, precision may be arbitrarily large (limited only by > available memory), fixed at compile time values, for example 50 decimal > digits, or a variable controlled at run-time by member functions. The types > are expression-template-enabled for better performance than naive > user-defined types." > -------- > > And from the original formal review request from John: > > -------- > Features: > > * Expression template enabled front end. > * Support for Integer, Rational and Floating Point types. > > Supported Integer backends: > > * GMP. > * Libtommath. > * cpp_int. > > cpp_int is an all C++ Boost licensed backend, supports both arbitrary > precision types (with Allocator support), and signed and unsigned fixed > precision types (with no memory allocation). > > There are also some integer specific functions - for Miller Rabin testing, > bit fiddling, random numbers. Plus interoperability with Boost.Rational > (though that loses the expression template frontend). > > Supported Rational Backends: > > * GMP > * libtommath > * cpp_int (as above) > > Supported Floating point backends: > > * GMP > * MPFR > * cpp_dec_float > > cpp_dec_float is an all C++ Boost licensed type, adapted from Christopher > Kormanyos' e_float code (published in TOMS last year). > > All the floating point types, have full std lib support (cos sin exp, pow > etc), as well as full interoperability with Boost.Math. > > There's nothing in principal to prevent extension to complex numbers and > interval arithmetic types (plus any other number types I've forgotten!), > but I've run out of energy for now ;-) > > Code is in the sandbox under /big_number/. > > Docs can be viewed online here: > http://svn.boost.org/svn/boost/sandbox/big_number/libs/multiprecision/doc/h… > -------- > Any review discussion should take place on the developers' list ( boost(a)lists.boost.org) and anyone may submit a formal review, either publicly to the entire list or privately to just myself. As usual, please consider the following questions in your formal review: What is your evaluation of the design? What is your evaluation of the implementation? What is your evaluation of the documentation? What is your evaluation of the potential usefulness of the library? Did you try to use the library? With what compiler? Did you have any problems? How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? Are you knowledgeable about the problem domain? And, most importantly, please explicitly answer the following question: Do you think the library should be accepted as a Boost library? Lastly, please consider that John and Christopher have compiled a TODO list [1] based on pre-review comments. Feel free to comment on the priority and necessity of such TODO items, and whether any might be show-stoppers or warrant conditional acceptance of the library. Thanks in advance; looking forward to the discussion! - Jeff (& John & Christopher) [1] http://svn.boost.org/svn/boost/sandbox/big_number/libs/multiprecision/doc/h…

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[filesystem] is path comparison case-insensitive on Windows?
by Nathan Ridge 16 Jun '12

16 Jun '12

Hi, I couldn't find this info in the Filesystem documentation, so I thought I'd ask here: is equality comparison between path objects case-insensitive on Windows? I think it ought to be, since the operating system treats two paths differing by case only to be the same, but I thought I'd double-check. Thanks, Nate

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positional arguments in boost::program_options
by Evan Driscoll 15 Jun '12

15 Jun '12

Hi, I'm writing a program which will run other programs (think xargs) and I have the following question. If I am reading the docs right, I get positional arguments by doing something like 1) Make a "normal" argument --arg 2) Tell it that positional arguments map to --arg However, if I do this, that means that if someone runs my_wrapper target_program --arg a then the --arg "disappears" because boost::po treats it as an actual option and not a positional argument. I can (mostly) get around this by naming all the fake positional arguments something like --ZZZZarg and assuming no one will ever want to pass that to another program, but it's a bit unsatisfactory conceptually. Is there a better way? Evan

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signals2 multithreading with dumb pointers
by Chris Stankevitz 15 Jun '12

15 Jun '12

Hello, I have a problem that is turning to a big mess. I'm having trouble wrapping my brain around it enough to even ask a good question. Can you recommend techniques/classes/patterns to get me out of this mess? Thank you! 1. I have a "model" whose state changes 2. State changes are advertised via boost::siganls2. Signals are fired at up to 30 Hz. 2a. I have a lot of signals advertising a lot of different state changes. e.g. "employee name changed; employee age changed; etc" 2b. Signals are fired from different threads 3. I have a dialog that shows the state of the model. 4. The dialog connects to the signals and update the screen to reflect the changing state of the model. 4a. (4) is somewhat complicated by the fact that screen updates must happen on a particular "main" thread. I have some plumbing to deal with this and I believe it is logically safe. 5. Unfortunately, the dialog class cannot live inside a boost::shared_ptr. This is a requirement of wxWidgets. 5a. (5) means my dialogs cannot connect to "tracked" signals. 6. Unfortunately, wxWidgets sometimes delete (in the c++ "delete" sense) the dialog 'without warning'. 6a. (6) means my dialog destructor might be called while it is simultaneously receiving a signal. 7. In my dialog destructor I disconnect all boost::signals2::connections. 8. (7) does not wait signals to complete for returning. i.e. the disconnect will return immediately eventhough the signal is still "running" 8a. (8) can cause a crash 9. I deal with (8) by adding a "dialog facade", but I'm curious about other ways to do this. 9a. The "dialog facade" receives all signals and forwards them to the dialog iff the dialog is attached. 9b. While each signal is being serviced a shared_lock is kept 9c. The "dialog facade" lives in a shared_ptr and uses boost::signals2::slot_type::track() 9d. The dialog destructor first notifies the facade to "detach" from the dialog 9e. The "detach" function grabs a unique_lock and disconnects all boost::signals2::connections. This effectively implements a blocking version of (7) 10. (9) is a lot of work for all my dialogs with all my signals. 10a. (4a) makes (9) even uglier! Can you recommend techniques/classes/patterns to get me out of this mess? Thank you, Chris

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Re: [Boost-users] 1.49 header order conflicts on Windows
by Brian Wood 14 Jun '12

14 Jun '12

Lars Viklund: > Asio is "friendly" enough to define WIN32_LEAN_AND_MEAN for you, which > pretty much breaks any other consumer of Windows.h. I wasn't aware that that's a no-no and am doing the same thing. My code doesn't compile without the define so am wondering what can be done to help. I'm also having another problem on Windows https://groups.google.com/forum/?fromgroups#!topic/comp.lang.c++/Hpoi2pbQD74 Shalom, Brian Wood Ebenezer Enterprises http://webEbenezer.net

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[Container] [Intrusive] [Interprocess] Flat Intrusive Containers?
by Hering Cheng 14 Jun '12

14 Jun '12

Hi, While Boost.Intrusive provides more varieties of containers than Boost.Container, I wonder if it would make sense to provide flat maps or sets. The application I have in mind is to use these flat containers in shared memory in such a way that application programs preallocate all memory, just like it is possible with Instrusive containers. Would this be feasible? If this makes sense, is there any plan to make this available? Thanks. Hering

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1.49 header order conflicts on Windows
by Davidson, Josh 14 Jun '12

14 Jun '12

Consider this following simple app: #include <boost/thread/thread.hpp> #include <boost/asio.hpp> #include <boost/thread/recursive_mutex.hpp> int main() { return 0; } If you try to build that on Windows, you receive the following error: In file included from c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/recursive_mutex.hpp:14:0, from c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/recursive_mutex.hpp:14, from build.cpp:3: c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/basic_recursive_mutex.hpp: In member function 'void boost::detail::basic_recursive_mutex_impl<underlying_mutex_type>::lock()': c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/basic_recursive_mutex.hpp:52:21: error: '_InterlockedExchange' is not a member of 'boost::detail' c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/basic_recursive_mutex.hpp: In member function 'void boost::detail::basic_recursive_mutex_impl<underlying_mutex_type>::unlock()': c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/basic_recursive_mutex.hpp:71:21: error: '_InterlockedExchange' is not a member of 'boost::detail' c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/basic_recursive_mutex.hpp: In member function 'bool boost::detail::basic_recursive_mutex_impl<underlying_mutex_type>::try_basic_lock(long int)': c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/basic_recursive_mutex.hpp:91:21: error: '_InterlockedExchange' is not a member of 'boost::detail' c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/basic_recursive_mutex.hpp: In member function 'bool boost::detail::basic_recursive_mutex_impl<underlying_mutex_type>::try_timed_lock(long int, const boost::system_time&)': c:/mingw/lib/gcc/../../x86_64-w64-mingw32/include/boost/thread/win32/basic_recursive_mutex.hpp:102:21: error: '_InterlockedExchange' is not a member of 'boost::detail' If asio.hpp is moved ahead of the thread headers, the error goes away. We've been trying to dictate #include order to work around this problem, but it keeps cropping up.

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why boost is so slow for file search?
by young 13 Jun '12

13 Jun '12

I have 2 functions for read files list in one directory. One uses Win32 and one uses boost: void GetFilesWin32(std::string dir) { std::vector<std::string> vFiles; std::string f = dir + "*.*"; std::string file; WIN32_FIND_DATA findFileData; HANDLE h = FindFirstFile(f.c_str(), &findFileData); if(h != INVALID_HANDLE_VALUE) { do { if((findFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != FILE_ATTRIBUTE_DIRECTORY) { file = findFileData.cFileName; vFiles.push_back( file); } } while( FindNextFile( h, &findFileData) != 0); } FindClose(h); } void GetFilesBoost(std::string dir) { namespace fs = boost::filesystem; std::vector<std::string> vFiles; fs::path path(dir); fs::directory_iterator end_dir; for(fs::directory_iterator it(path); it != end_dir; it++) { if(!(fs::is_directory(it->status()))) { vFiles.push_back(it->path().filename().string()); } } } Boost takes 1.00 ms while Win32 taks 0.15 ms for same directory. Why? -- View this message in context: http://boost.2283326.n4.nabble.com/why-boost-is-so-slow-for-file-search-tp4… Sent from the Boost - Users mailing list archive at Nabble.com.

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[vector, PropertyGraph] Problem declaring a class member of the "vector<int>" type
by Alex Sadovsky 13 Jun '12

13 Jun '12

Hello everyone, > >I am trying to declare, in a header file, a class that has a member of type "vector<double>" (the code is included below). The compiler complains that I haven't included the appropriate namespace (the error message reads, "ISO C++ forbids declaration of ‘vector’ with no type"), and I understand that it is looking for this: > >using namespace boost::numeric::ublas; > >However, I tried putting it in the header file in various places (haven't programmed in C++ in 10 years and couldn't find any online documentation to clarify this specific situation), and still no luck. I am definitely doing something wrong, but cannot reason out the error, as it probably has to do with the specific syntax conventions. Any help is appreciated! > >Thanks, >-Al > >P.S. Code in header file: > >////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// >// File "airspace-graph-rectilinear-edges.h" >typedef char* string; >const int PHYSICAL_SPACE_DIMENSION = 2; >// Information needed about a waypoint used in an airspace: name and physical position >class WaypointConcept{ > private: > using namespace boost::numeric::ublas; > string waypoint_name; > vector<double> waypoint_position_xyh(PHYSICAL_SPACE_DIMENSION); > public: > string GetWaypointName(); > vector<double> GetWaypointPosition(); >} > >class AirspaceGraphConcept PropertyGraphConcept<class Graph, class WaypointConcept, class vertex_index_t>; >typedef Vertex* GraphPathType; >typedef string FlightIDType; >typedef boost::unordered_map<std::FlightIDType, GraphPathType> FlightIDToPathAssignmentType; >////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// > >Code in the .cpp file (which includes the above header file) I am trying to compile: >////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// >#include <boost/lambda/lambda.hpp> >#include <iostream> >#include <iterator> >#include <algorithm> >#include <boost/numeric/ublas/io.hpp> >#include <boost/numeric/ublas/vector.hpp> >#include "airspace-graph-rectilinear-edges.h" > >int main() >{ > using namespace boost::numeric::ublas; > > vector<double> v(3); > for (unsigned i = 0; i < v.size(); ++ i) > v (i) = 2.01*double(i); > > std::cout << v << std::endl; >} >////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// > > > > > > > > > > > > > > > >

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[lockfree] minor bug/improvement
by Brian Budge 13 Jun '12

13 Jun '12

Hi all - I'm unsure of the status of the lockfree library. Where should I be posting bugs for that? Thanks, Brian

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msvc2010, _Rechecked and function_output_iterator
by Paul Harris 13 Jun '12

13 Jun '12

Hi all, I am trying to compile some code in Release mode in MSVC 2010, see below error message, I am looking for a workaround or solution, and so far all I can find is something to do with boost::multi_array https://svn.boost.org/trac/boost/ticket/4874 but the solution and patch seems to be targeted at only multi_array. Has anyone else tackled this before? thanks, Paul 34>c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\xutility(275): error C2582: 'operator =' function is unavailable in 'boost::function_output_iterator<UnaryFunction>' 34> with 34> [ 34> UnaryFunction=utils::output_counter 34> ] 34> c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\xutility(2176) : see reference to function template instantiation '_Iter &std::_Rechecked<_OutIt,_OutIt>(_Iter &,_UIter)' being compiled 34> with 34> [ 34> _Iter=boost::function_output_iterator<utils::output_counter>, 34> _OutIt=boost::function_output_iterator<utils::output_counter>, 34> _UIter=boost::function_output_iterator<utils::output_counter> 34> ] 34> c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\algorithm(4681) : see reference to function template instantiation '_OutIt std::copy<_InIt1,_OutIt>(_InIt,_InIt,_OutIt)' being compiled 34> with 34> [ 34> _OutIt=boost::function_output_iterator<utils::output_counter>, 34> _InIt1=int *, 34> _InIt=int * 34> ]

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weak_ptr copying causes destruction
by Travis Gockel 13 Jun '12

13 Jun '12

The copy constructor for weak_ptr constructs px like so: px(r.lock().get()) Why do it this way and not just: px(r.px) This introduces a somewhat unexpected race in that the shared_ptr obtained with lock() can be the last outstanding shared_ptr and the object can be destroyed during this copy. It is certainly not a *bug* in the smart_ptr library, but the behavior is unexpected and quite inconvenient. I assume there is a reason for calling lock() and not just copying the pointer and I would like to know what it is. Thanks, Travis Gockel Chief λ Combinator

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[boost-build] linking against pre-built libraries
by Jarosław Bober 13 Jun '12

13 Jun '12

Hello, What I'm trying to accomplish is to link against pre-built boost library that lives in $BOOST_ROOT/stage/lib, but the default naming convention comes with a boost version at the end: boost_unit_test_framework-vc80-mt-gd-1_47.lib I don't want to hardcode the exact name because some clients use older version of boost. unfortunatelly I cannot do something like this (or maybe I'm wrong): exe myExe : some.cpp /boost//unit_test_framework because that would build test library and I want to prevent that. I want to keep variants and compiler version in the name so --layout=system and --layout=tagged does not help me either. One solution would be to get rid of the boost version suffix(prefferable) and second would be to read BOOST_VERSION from boost/Jamroot and append that to the name of a library file, because I don't want clients to hardcode their boost version in jamfiles manually. How do I do that? Regards

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[property_tree] number of sections in an inifile
by Sean Farrow 13 Jun '12

13 Jun '12

Hi: If I have defined: boost::property_tree::ptree IniTree; What is the correct way to determine how many sections there are in an ini file. Should I use count, max_size, m_children or size? Any help appreciated. Cheers Sean.

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[MPL] mpl::at for AssociativeSequence
by dariomt＠gmail.com 13 Jun '12

13 Jun '12

Hi list, I'm trying to use the version of mpl::at with three template parameters, as specified here ( http://www.boost.org/doc/libs/1_46_0/libs/mpl/doc/refmanual/at.html) But I'm getting a compiler error saying 'boost::mpl::at' : too many template arguments. What am I doing wrong? #include <boost/mpl/map.hpp> #include <boost/mpl/at.hpp> #include <boost/mpl/size.hpp> #include <boost/mpl/empty.hpp> #include <boost/type_traits/is_same.hpp> using namespace boost; using namespace boost::mpl; typedef map< pair<int,unsigned> , pair<char,unsigned char> , pair<long_<5>,char[17]> , pair<int[42],bool> > m; BOOST_MPL_ASSERT_RELATION( size<m>::value, ==, 4 ); BOOST_MPL_ASSERT_NOT(( empty<m> )); BOOST_MPL_ASSERT(( is_same< at<m,int>::type, unsigned > )); BOOST_MPL_ASSERT(( is_same< at<m,long_<5> >::type, char[17] > )); BOOST_MPL_ASSERT(( is_same< at<m,int[42]>::type, bool > )); BOOST_MPL_ASSERT(( is_same< at<m,long>::type, void_ > )); BOOST_MPL_ASSERT(( is_same< at<m,long,void_>::type, void_ > )); // fails!

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question for use filesystem in vc++ with PPL
by young 12 Jun '12

12 Jun '12

I have question for use filesystem in vc++ with PPL. The code is listed here: #include <ppl.h> #include <boost/filesystem.hpp> namespace fs = boost::filesystem; std::vector<std::string> vFiles; fs::path path(dir); fs::directory_iterator end_dir; Concurrency::parallel_for((fs::directory_iterator) (path), end_dir, [&](fs::directory_iterator it) { if(!(fs::is_directory(it->status()))) { vFiles.push_back(it->path().filename().string()); } }); But it build failed with message: Eerror C2653: 'fs' : is not a class or namespace name what is wrong? I use Visual Studio 2010. -- View this message in context: http://boost.2283326.n4.nabble.com/question-for-use-filesystem-in-vc-with-P… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Phoenix] using container algorithms
by Paul Heil 12 Jun '12

12 Jun '12

have a Visual Studio 2008 C++03 application using boost 1.49 phoenix. I would like to define a boost::function to remove an element from a list. For example: #include <boost/phoenix.hpp> #include <boost/function.hpp> #include <boost/phoenix/stl/container.hpp> #include <boost/phoenix/stl/algorithm/transformation.hpp> #include <algorithm> #include <list> int main() { namespace bp = boost::phoenix; namespace bpa = boost::phoenix::arg_names; std::list< int > a; boost::function< void( int ) > RemoveFromList = bp::remove( bp::ref( a ), bpa::arg1 ); return 0; } but I get a series of compiler errors on my RemoveFromList definition. Error 1 error C2504: 'boost::phoenix::impl::remove::result<Sig>' : base class undefined \boost\utility\result_of.hpp 80 Error 2 error C2039: 'type' : is not a member of 'boost::result_of<F>' \boost\phoenix\core\detail\preprocessed\function_eval_10.hpp 121 Error 3 error C2146: syntax error : missing ';' before identifier 'type' \boost\phoenix\core\detail\preprocessed\function_eval_10.hpp 122 Error 4 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int \boost\phoenix\core\detail\preprocessed\function_eval_10.hpp 122 Error 5 error C2602: 'boost::phoenix::detail::function_eval::result<Sig>::type' is not a member of a base class of 'boost::phoenix::detail::function_eval::result<Sig>' \boost\phoenix\core\detail\preprocessed\function_eval_10.hpp 122 Error 6 error C2868: 'boost::phoenix::detail::function_eval::result<Sig>::type' : illegal syntax for using-declaration; expected qualified-name \boost\phoenix\core\detail\preprocessed\function_eval_10.hpp 122 A similar function AddToList compiles cleanly: boost::function< void( int ) > AddToList = bp::push_back( bp::ref( a ), bpa::arg1 ); This also works correctly (but is much less elegant): boost::function< void( int ) > RemoveFromList = bp::bind( &std::remove< std::list< int >::iterator, int >, a.begin(), a.end(), bpa::arg1 ); What is the correct way to use the boost.phoenix.remove function? Thanks

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time conversion
by young 11 Jun '12

11 Jun '12

I would like to convert utc time to local time. I found 2 headers which confuse me. #include <boost/date_time/local_time_adjustor.hpp> #include <boost/date_time/c_local_time_adjustor.hpp> which one to use? c_local_adjustor or local_adjustor? what is the difference? -- View this message in context: http://boost.2283326.n4.nabble.com/time-conversion-tp4631162.html Sent from the Boost - Users mailing list archive at Nabble.com.

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[Nowide] Formal Review Request
by Artyom Beilis 11 Jun '12

11 Jun '12

Hello, I'd like to ask to add Boost.Nowide to review queue: Boost.Nowide is a library implemented by Artyom Beilis that make cross platform Unicode aware programming easier. The library provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. Sources: http://cppcms.com/files/nowide/ Docs: http://cppcms.com/files/nowide/html/ Git: git://cppcms.git.sourceforge.net/gitroot/cppcms/nowide Thank You Very Much! Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.com/ CppDB - C++ SQL Connectivity: http://cppcms.com/sql/cppdb/

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[filesystem] converting boost::filesystem::wofstream to std::ostream
by Sean Farrow 10 Jun '12

10 Jun '12

Hi: I have a library that takes a function taking an std::ostream &. Is it possible to convert a boost::filesystem::wofstream to an std::ostream. Any help appreciated. Cheers Sean.

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question about boost pointer
by young 10 Jun '12

10 Jun '12

I have question about boost pointer. If I define a pointer by using: boost::shared_ptr<int> p; How to use p to get next int? In classic c++ pointer, I could use *(p+1). How to do it in Boost? -- View this message in context: http://boost.2283326.n4.nabble.com/question-about-boost-pointer-tp4631069.h… Sent from the Boost - Users mailing list archive at Nabble.com.

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