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

Re: [Boost-users] The GMANE archive is not searchable
by Steinar Bang 17 Nov '11

17 Nov '11

>>>>> giecrilj(a)stegny.2a.pl: > The page "Boost Mailing Lists" [1] constains a hyperlink to what is > called "Gmane's searchable archive" [2]. However, the page in > question contains no search form; Actually the page in [2] does contain a search form at the bottom. However,... > Actually, it is possible to perform a search using the Group > Information interface [3]. Please adjust the hyperlink accordingly. ...personally I would have linked to [3], since that page has links to all ways of accessing the archives, statistics, as well as an easily visible search form. > [1] <URL: http://www.boost.org/community/groups.html#users > > [2] <URL: http://news.gmane.org/gmane.comp.lib.boost.user > > [3] <URL: http://dir.gmane.org/gmane.comp.lib.boost.user >

1 0

dubious range mismatch prerequisite
by Krzysztof Żelechowski 17 Nov '11

17 Nov '11

The documentation for mismatch, as applied to ranges, says that rng2 must be at least as long as rng1. Why is this precondition necessary? The precondition is impossible to evaluate for bare input iterators without destroying the iterators, whereupon it is impossible to call mismatch any more. IMHO, it would be perfectly reasonable to stop at the end of rng2 if rng2 is shorter. <URL: http://www.boost.org/doc/libs/1_47_0/libs/range/ doc/html/range/reference/algorithms/non_mutating/mismatch.html >

2 1

Re: [Boost-users] BOOST ASIO Strange behaviour
by Marat Abrarov 17 Nov '11

17 Nov '11

Hi, Gokul. > I am noticing consistently that DEBUG Version of ASIO is slightly faster > than the Release version consistently. The difference is around 5-10%. What does this 5-10% mean? Throughput? Regards, Marat Abrarov.

2 2

recursive_variant map recursion / incomplete type error
by Bodmer Marc 17 Nov '11

17 Nov '11

Hi I try to use boost::recursive_variant with a recursive std::map. There are several projects and examples on the internet using boost::recursive_variant exactly like I do and it seems to work there. But somehow I can not make it compile in my environment. I am using gcc 4.6.1 and boost 1.46.1. I've stripped my code down to this: ------------------------------------------------------------- #include <boost/variant.hpp> #include <map> typedef boost::make_recursive_variant< int, std::map<float, boost::recursive_variant_> >::type element; int main () { element i = 42; } But I always get these errors about uncomplete types (see attachments for full compiler output and code): ------------------------------------------------------------- /usr/include/c++/4.6/bits/stl_pair.h:93:11: error: 'std::pair<_T1, _T2>::second' has incomplete type /usr/include/boost/variant/variant_fwd.hpp:232:12: error: forward declaration of 'struct boost::recursive_variant_' used compile command: ------------------------------------------------------------ gcc recursive_variant_stripped.cpp 2> gccout.txt Thanks for any help and suggestions regards Marc

1 0

[boost-users] [regex] Problem on Solaris
by Kunth, Thomas (ext) 17 Nov '11

17 Nov '11

Hello! I am currently observing a strange crash on my test systems. The core file tells me that it happens when constructing a regular expression from a string for the first time. We are using boost 1.33.1. Please find below some system details. Configuration no. 1 is the current stable workung one. In configuration no. 2 my program crashes in the constructor of boost::regex. The crash seems to be caused by some threading related functions, but the application is single threaded. The call stack is attached to this e-mail. In configuration no. 3 my program does not crash, but hangs at nearly the same position inside the boost::regex constructor. Again inside some threading related functions of my single threaded application. It is related to my system configuration. Here are the ones I use: 1. This configuration works since years * Compilation of libboost_regex: SunOS 5.8 Generic_117350-35 sun4u sparc SUNW,Sun-Blade-2500 CC: Sun WorkShop 6 update 2 C++ 5.3 Patch 111685-24 2006/11/03 * Compilation of my application SunOS 5.8 Generic_117350-35 sun4u sparc SUNW,Sun-Blade-2500 CC: Sun WorkShop 6 update 2 C++ 5.3 Patch 111685-24 2006/11/03 * Execution environment SunOS 5.8 Generic_117350-35 sun4u sparc SUNW,Sun-Fire-V240 2. We are noe migrating to Solaris 10. This is causing problems. First we just change the execution environment: * Execution environment SunOS 5.10 Generic_141444-09 sun4u sparc SUNW,Sun-Fire-V210 3. Then we also change the compilation environment: * Compilation of libboost_regex is not changed. Libraries have not even been re-compiled. * Compilation of my application SunOS 5.10 Generic_141414-01 sun4u sparc SUNW,SPARC-Enterprise CC: Sun WorkShop 6 update 2 C++ 5.3 Patch 111685-24 2006/11/03 * Execution environment SunOS 5.10 Generic_141444-09 sun4u sparc SUNW,Sun-Fire-V210 I cannot change these configurations. But I would have the chance to move to a newer version of boost if it would compile with my legacy compiler (which it doesn't). Please help me solving this problem! Thanks in advance! With best regards, Thomas

1 0

Re: [Boost-users] [variant] declaring recursive variants (Jerry Jeremiah)
by 乔志强 17 Nov '11

17 Nov '11

binary '==' : no operator found which takes a left-hand operand of type 'const T2' and T2=config_iter so you need bool config_iter::operator == (const config_iter & other) const; struct config_iter { config_iter(const config::iterator iter) : iter_(iter) {} operator config::iterator() const { return iter_; } config::iterator operator() () const { return iter_; } //////ADD THIS////////////////////// bool operator == (const config_iter & other) const { return iter_ == other.iter_; } //////ADD THIS////////////////////// protected: config::iterator iter_; }; //////// SEE HERE /////////////////////////////////// 1>.\boost\variant\variant.hpp(781): error: binary '==' : no operator found which takes a left-hand operand of type 'const T2' (or there is no acceptable conversion) //////// SEE HERE /////////////////////////////////// 1> .\boost\blank.hpp(58): could be 'bool boost::operator ==(const boost::blank &,const boost::blank &)' 1> while trying to match the argument list '(const T2, const T2)' 1> .\boost\variant\variant.hpp(763) : see reference to function template instantiation 'bool boost::detail::variant::equal_comp::operator ()<T>(const T &,const T &) const' being compiled 1> with 1> [ 1> T=T2 1> ] 1> .\boost\variant\variant.hpp(832) : see reference to function template instantiation 'bool boost::detail::variant::comparer<Variant,Comp>::operator ()<const T>(const T &) const' being compiled 1> with 1> [ 1> Variant=boost::variant<std::string,long double,config_iter>, 1> Comp=boost::detail::variant::equal_comp, 1> T=T2 1> ] 1> .\boost\variant\detail\visitation_impl.hpp(130) : see reference to function template instantiation 'bool boost::detail::variant::invoke_visitor<Visitor>::internal_visit<const T>(T &,int)' being compiled 1> with 1> [ 1> Visitor=boost::detail::variant::comparer<boost::variant<std::string,long double,config_iter>,boost::detail::variant::equal_comp>, 1> T=T2 1> ] 1> .\boost\variant\detail\visitation_impl.hpp(173) : see reference to function template instantiation 'bool boost::detail::variant::visitation_impl_invoke_impl<Visitor,VoidPtrCV,T>(int,Visitor &,VoidPtrCV,T *,boost::mpl::true_)' being compiled 1> with 1> [ 1> Visitor=boost::detail::variant::invoke_visitor<boost::detail::variant::comparer<boost::variant<std::string,long double,config_iter>,boost::detail::variant::equal_comp>>, 1> VoidPtrCV=const void *, 1> T=T2 1> ] 1> .\boost\variant\detail\visitation_impl.hpp(256) : see reference to function template instantiation 'bool boost::detail::variant::visitation_impl_invoke<Visitor,VoidPtrCV,T2,NoBackupFlag>(int,Visitor &,VoidPtrCV,T *,NoBackupFlag,int)' being compiled 1> with 1> [ 1> Visitor=boost::detail::variant::invoke_visitor<boost::detail::variant::comparer<boost::variant<std::string,long double,config_iter>,boost::detail::variant::equal_comp>>, 1> VoidPtrCV=const void *, 1> NoBackupFlag=boost::variant<std::string,long double,config_iter>::has_fallback_type_, 1> T=T2 1> ] 1> .\boost\variant\variant.hpp(1776) : see reference to function template instantiation 'bool boost::detail::variant::visitation_impl<first_which,first_step,Visitor,VoidPtrCV,boost::variant<T0_,T1,T2>::has_fallback_type_>(const int,const int,Visitor &,VoidPtrCV,boost::mpl::false_,NoBackupFlag,Which *,step0 *)' being compiled 1> with 1> [ 1> Visitor=boost::detail::variant::invoke_visitor<boost::detail::variant::comparer<boost::variant<std::string,long double,config_iter>,boost::detail::variant::equal_comp>>, 1> VoidPtrCV=const void *, 1> T0_=std::string, 1> T1=long double, //////// SEE HERE /////////////////////////////////// 1> T2=config_iter, //////// SEE HERE /////////////////////////////////// 1> NoBackupFlag=boost::variant<std::string,long double,config_iter>::has_fallback_type_, 1> Which=first_which, 1> step0=first_step 1> ] // test program with config_iter and indentifier // doesn't compile if identifier::operator==() is in the program #include <boost/variant.hpp> #include <iterator> #include <string> #include <vector> #include <list> #include <map> struct config_iter; typedef boost::variant<std::string ,long double ,config_iter > var; typedef std::vector<var> value; typedef std::map<std::string,value> message; typedef std::map<std::string,message> config; struct config_iter { config_iter(const config::iterator iter) : iter_(iter) {} operator config::iterator() const { return iter_; } config::iterator operator() () const { return iter_; } protected: config::iterator iter_; }; struct identifier { identifier() : name_(""), version_({0}) { // std::cout << "identifier::identifier()" << std::endl; } identifier(const std::string & name, const value & version) : name_(name), version_(version) { // std::cout << "identifier::identifier(" << name << "," << version << ")" << std::endl; } bool operator == (const identifier & other) const { return name_ == other.name_ && version_ == other.version_; } private: // updated by constructor std::string name_; value version_; }; int main() { return 0; }

1 0

Lisp/Scheme DSEL in C++?
by Nathan Ridge 17 Nov '11

17 Nov '11

Hello, I came across the following post on boost-users [1]: >> hello all, >> >> does anybody know of an existing spirit/lisp implimentation, and is there >> any interest in developing such a project in open source? > > None yet, AFAIK. > > I'll be writing an example for Spirit2 to complement the tiny-C > virtual machine in there. What's equally interesting though is > that scheme (or at least a subset of it) can be implemented in > pure c++. No parsing, just pure DSEL in C++. Now, imagine a > parser that targets this DSEL (through C++) -- a source to source > translator. Essentially, your scheme code will be compiled into > highly efficient C++. I find this quite intriguing, and I'm naturally led to ask two questions: 1. Which subset of Scheme can be implemented in this way, with a DSEL? 2. Has anyone actually done this? Thanks! Nate [1] http://thread.gmane.org/gmane.comp.lib.boost.user/30512

2 3

[variant] declaring recursive variants
by Jerry Jeremiah 16 Nov '11

16 Nov '11

> Hello, Actually, I don't want a recursive variant in the normal recursive_wrapper sense. What I want is this: typedef std::list<a> alist; typedef std::list<b> blist; typedef boost::variant<std::string ,long double ,alist::iterator ,blist::iterator ,config::iterator > var; typedef std::vector<var> value; typedef std::map<std::string,value> message; typedef std::map<std::string,message> config; But of course I can't do that because I have no idea how to forward declare config. I suspect that there is no way to do this, but I am not in the same league as everybody else when it comes to this stuff. Any suggestions? Thank you, Jerry

2 2

[gil] Constructing view from locator
by Sapp, Mark 16 Nov '11

16 Nov '11

Hi All, I'm trying to iterate through each pixel in a view and calculate the average of the 9x9 pixels surrounding it. I initially tried following the convolution example, but it's performance isn't fast enough for my needs. I have tried several ways of iterating through the pixels on the 136x98 test image provided with the gil: attempt #1 executes in ~400 ms convolve_rows_fixed<rgb32f_pixel_t>(src1,kernel,dst); convolve_cols_fixed<rgb32f_pixel_t>(dst,kernel,dst); attempt #2 executes in ~26000 ms vector<vector<double>> window(windowSizeX, vector<double> (windowSizeY, 1.0 / 81)); for (int y = 0; y <= src1.height(); ++y) { for (int x = 0; x < src1.width(); ++x) { for (int yi = y - windowRadiusY; yi <= y + windowRadiusY; ++yi) { if (yi >= 0 && yi <= src1.height()) { typename SrcView1::x_iterator src1_it=src1.row_begin(y); typename SrcView2::x_iterator src2_it=src2.row_begin(y); typename DstView::x_iterator dst_it=dst.row_begin(y); for (int xi = x - windowRadiusX; xi <= x + windowRadiusX; ++xi) { vector<double> ux, ux2, uy, uy2, uxy = vector<double>(numChannels, 0); ux = ux2 = uy = uy2 = uxy; if (xi >= 0 && xi <= src1.width()) { int winX = xi - x + windowRadiusX; int winY = yi - y + windowRadiusY; double winTotal = 0; for (int c = 0; c < numChannels; ++c) { ux[c] += window[winX][winY] * typename SrcView1::value_type(src1_it[xi])[c]; winTotal += window[winX][winY]; } // Normalize calculation for (int c = 0; c < numChannels; ++c) { ux[c] = ux[c] / winTotal; } } } } } } } So now I'm attempting to run the following but having trouble: ... template <typename SrcView1, typename SrcView2, typename DstView> double function(const SrcView1& src1, const SrcView2& src2, const DstView& dst) { typedef typename channel_type<DstView>::type dstChannelType; transform_pixel_positions(src1, src2, dst, operator<dstChannelType>()); } ... template <typename Out> struct operator { template <typename T> Out operator()(const T& in1, const T& in2) const { rgb8_view_t subView1 = rgb8_view_t(9,9,in1); // in1 throws type mismatch rgb8_view_t subView2 = rgb8_view_t(9,9,in2); // in2 throws type mismatch Out retVal; transform_pixels(subView1, subView2, retVal, average()); return rgb8_pixel_t(0,0,0); } }; Can you explain if this is an appropriate way to construct a subview and how I can retrieve the locator needed as the 3rd parameter to rgb8_view_t(), specifically I need the locator for 4 pixels left and 4 pixel up so that the average window is centered on in1/in2? Also, is it possible to get the view type from the locator inputs in1 and in2 so that I can change the subView instantiantion to in1Type subView1 = in1Type(9,9,in1)? It seems that the performance, with regard to speed, is much better using transform_pixel or transform_pixel_positions over iterating through the pixels myself unless I am doing something incorrect. Are there any other programming styles that provide better performance for doing similar calculations on groups of pixels? As always, I greatly appreciate any help as I'm learning. Thanks, Mark Sapp Notice: This e-mail is intended solely for use of the individual or entity to which it is addressed and may contain information that is proprietary, privileged, company confidential and/or exempt from disclosure under applicable law. If the reader is not the intended recipient or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If this communication has been transmitted from a U.S. location it may also contain data subject to the International Traffic in Arms Regulations or U.S. Export Administration Regulations and cannot be disseminated, distributed or copied to foreign nationals, residing in the U.S. or abroad, without the prior approval of the U.S. Department of State or appropriate export licensing authority. If you have received this communication in error, please notify the sender by reply e-mail or collect telephone call and delete or destroy all copies of this e-mail message, any physical copies made of this e-mail message and/or any file attachment(s).

2 2

Re: [Boost-users] Boost 1.48.0 Release Notice
by Tom Kent 16 Nov '11

16 Nov '11

> Subject: [Boost-users] Boost 1.48.0 Release Notice > From: Beman Dawes (bdawes_at_[hidden]) > Date: 2011-11-16 07:33:06 > > Release 1.48.0 of the Boost C++ Libraries is now available. > These open-source libraries work well with the C++ Standard Library, > and are usable across a broad spectrum of applications. The Boost > license encourages both commercial and non-commercial use. > This release contains new libraries: Container, Locale, Move. Updated > libraries include: Asio, Chrono, Config, Fusion, Geometry, Graph, > Interprocess, Intrusive, Lexical cast, Math, MSM, Numeric Conversion, > Proto, Regex, Spirit, TypeTraits, Unordered, Wave, and more. For > details, including download links, see > http://www.boost.org/users/news/version_1_48_0 > You can also download directly from SourceForge: > http://sourceforge.net/projects/boost/files/boost/1.48.0/ > To install this release on your system, see > http://www.boost.org/doc/libs/release/more/getting_started/index.html > Thanks, > --The Boost release team > Beman Dawes > Daniel James > Eric Niebler > Rene Rivera > Vladimir Prus I've built windows libraries (vc8, vc9, vc10) for this (32 and 64 bit), if you want them, you can get them from my website: http://boost.teeks99.com Tom

3 2