- Boost-users - lists.boost.org

How to use graph properties
by Paolo Bolzoni 11 Feb '14

11 Feb '14

Dear list, I need to keep track of two special vertices in my graph, So I thought to attach two vertex_descriptor as graph properties so have easy access any moment. Properties work fine for edges or vertices, but I cannot make them work for the graph. In the bottom is the C++ code. The graph has the two properties, now how I cat get and put them? This code does not work and the error messages are impossible to read for me. Otherwise that is the way to keep graph-wise properties? The code compiles removing the two puts, so I assume the error is there. Yours sincerely, Paolo #include <boost/graph/adjacency_list.hpp> namespace boost { enum graph_source_t { graph_source = 100 }; BOOST_INSTALL_PROPERTY (graph, source); enum graph_destination_t { graph_destination = 101 }; BOOST_INSTALL_PROPERTY (graph, destination); } typedef size_t graph_vertex; typedef boost::adjacency_list < boost::vecS, boost::vecS, boost::undirectedS, boost::no_property, boost::no_property, boost::property < boost::graph_source_t, graph_vertex, boost::property < boost::graph_destination_t, graph_vertex, boost::no_property>>> graph_t; static_assert(std::is_same<graph_vertex, boost::graph_traits<graph_t>::vertex_descriptor>::value, "Check out the vertex descriptor type!"); int main() { using namespace boost; graph_t g; add_edge(0, 1, g); put(graph_destination, g, 0); put(graph_source, g, 1); }

2 2

Re: [Boost-users] Boost-users Digest, Vol 3709, Issue 1
by Deepa S 10 Feb '14

10 Feb '14

Hi Gennadiy, Yes I would like to know how I need to write my own main in this case? Also I was wondering if there is any workaround that was found other than re-writing the main? Thanks, Deepa Here is what I am trying to do, may not be the best way, but trying to re-run the test suite ts1 - 3 consecutive times to test for repeatability: bool init_unit_test_suite(int argc, char **argv) { test_suite* ts1 = BOOST_TEST_SUITE( "SKUResourcesTestSuite" ); ts1->add( BOOST_TEST_CASE(&TestCase1) ); ts1->add( BOOST_TEST_CASE(&TestCase2) ); framework::master_test_suite().add( ts1 ); for(int i = 0;i < 3;i++) { framework::master_test_suite().add( ts1 ); } return true; } Deepa S <mslvada <at> yahoo.com> writes: > Wanted to check if there was any resolution to the error indicated > in this post: > http://lists.boost.org/boost-users/2010/06/59564.php > > I am running into a similar issue and would like to know how to resolve it. What exactly is the issue? Do you want to write your own main? Gennadiy On Monday, February 10, 2014 10:30 PM, "boost-users-request(a)lists.boost.org" <boost-users-request(a)lists.boost.org> wrote: Send Boost-users mailing list submissions to boost-users(a)lists.boost.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.boost.org/mailman/listinfo.cgi/boost-users or, via email, send a message with subject or body 'help' to boost-users-request(a)lists.boost.org You can reach the person managing the list at boost-users-owner(a)lists.boost.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Boost-users digest..." Today's Topics: 1. Re: Regarding post: Using Boost.Test in Iteration (Gennadiy Rozental) 2. [container.string] why isn't memcpy used in the internals? (Adam Romanek) 3. Re: [container.string] why isn't memcpy used in the internals? (Ion Gazta?aga) 4. [property_tree] Compilation Problem when #including <boost/property_tree/json_parser.hpp> (Adi Shavit) 5. Re: [property_tree] Compilation Problem when #including <boost/property_tree/json_parser.hpp> (Edward Diener) ---------------------------------------------------------------------- Message: 1 Date: Mon, 10 Feb 2014 07:16:06 +0000 (UTC) From: Gennadiy Rozental <rogeeff(a)gmail.com> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Regarding post: Using Boost.Test in Iteration Message-ID: <loom.20140210T081523-687(a)post.gmane.org> Content-Type: text/plain; charset=us-ascii Deepa S <mslvada <at> yahoo.com> writes: > Wanted to check if there was any resolution to the error indicated > in this post: > http://lists.boost.org/boost-users/2010/06/59564.php > > I am running into a similar issue and would like to know how to resolve it. What exactly is the issue? Do you want to write your own main? Gennadiy ------------------------------ Message: 2 Date: Mon, 10 Feb 2014 09:18:20 +0100 From: Adam Romanek <romanek.adam(a)gmail.com> To: "boost-users(a)lists.boost.org" <boost-users(a)lists.boost.org> Subject: [Boost-users] [container.string] why isn't memcpy used in the internals? Message-ID: <52F88B4C.40707(a)gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Hi! Recently I've been trying to improve the performance of a code that makes heavy use of std::string (lots of constructions and destructions). My first thought was to use boost::container::string as it does not use reference-counting and uses small-string optimization, so it should be a perfect replacement for std::string when it comes to performance. Right... But the problem is that switching to boost::container::string only made things worse in the general case. I wrote "in the general case" because when strings to be held are small and SSO may be applied then boost::container::string outperforms std::string considerably. However, in the general case constructing boost::container::string from a C string is significantly slower than constructing std::string. My investigation showed that std::string uses memcpy to copy the C string into its buffer while boost::container::string does not. The memcpy comes from std::char_traits::copy so maybe boost::container::string could use it too? I guess the rest of operations from std::char_traits (find, move, assign etc.) could be utilized too as std::char_traits has been carefully crafted with performance in mind. Should I create a ticket for this issue? Best regards, Adam Romanek ------------------------------ Message: 3 Date: Mon, 10 Feb 2014 09:54:36 +0100 From: Ion Gazta?aga <igaztanaga(a)gmail.com> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [container.string] why isn't memcpy used in the internals? Message-ID: <52F893CC.8020703(a)gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed El 10/02/2014 9:18, Adam Romanek escribi?: > Hi! > > Recently I've been trying to improve the performance of a code that > makes heavy use of std::string (lots of constructions and destructions). > My first thought was to use boost::container::string as it does not use > reference-counting and uses small-string optimization, so it should be a > perfect replacement for std::string when it comes to performance. > > Right... But the problem is that switching to boost::container::string > only made things worse in the general case. I wrote "in the general > case" because when strings to be held are small and SSO may be applied > then boost::container::string outperforms std::string considerably. > However, in the general case constructing boost::container::string from > a C string is significantly slower than constructing std::string. > > My investigation showed that std::string uses memcpy to copy the C > string into its buffer while boost::container::string does not. The > memcpy comes from std::char_traits::copy so maybe > boost::container::string could use it too? I guess the rest of > operations from std::char_traits (find, move, assign etc.) could be > utilized too as std::char_traits has been carefully crafted with > performance in mind. > > Should I create a ticket for this issue? Yes, please. I'm slowly trying to benchmark and improve Boost.Container performance, I haven't started optimizing basic_string so your ticket could be a good start point. In a quick inspection I see that the constructor is dispatched to basic_string::assign(It, It) and that assignment is not optimized at all. I should definitely write a assignment function that dispatches to std::char_traits::copy, as it could be used to optimize several member functions. Best, Ion ------------------------------ Message: 4 Date: Mon, 10 Feb 2014 12:29:39 +0200 From: Adi Shavit <adishavit(a)gmail.com> To: boost-users(a)lists.boost.org Subject: [Boost-users] [property_tree] Compilation Problem when #including <boost/property_tree/json_parser.hpp> Message-ID: <CAEWUs4h_ExtG5fG9L=x2p0hss_f=r_eVyrwoPaTN-RYyJPcH0g(a)mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" Hi, On VS2010, the following code does not compile if I restore the commented out #include: *// #include <boost/property_tree/json_parser.hpp>* struct X { enum Labels { ERROR, ONE, TWO, THREE }; // problem => ^^^^^ }; void f() { X::Labels r = X::ERROR; // problem => ^^^^^ } The VS2010 errors are: t.cpp(5): error C2059: syntax error : 'constant' t.cpp(5): error C2143: syntax error : missing ';' before '}' t.cpp(5): error C2238: unexpected token(s) preceding ';' t.cpp(7): error C2059: syntax error : '}' t.cpp(7): error C2143: syntax error : missing ';' before '}' t.cpp(7): error C2059: syntax error : '}' t.cpp(11): error C2589: 'constant' : illegal token on right side of '::' t.cpp(11): error C2059: syntax error : '::' It seems that somewhere inside the #include hierarchy the symbol ERROR is #defined to cause this code to fail. Renaming ERROR to something else avoids this problem. I think I tracked it into ' boost/spirit/home/classic/iterator/impl/file_iterator.ipp' but I'm not sure where exactly it is coming from. Adi

2 1

[MPL] implementing a "trait"?
by John M. Dlugosz 10 Feb '14

10 Feb '14

I want to mark certain types as being of a category of my invention (e.g. is_pretty), for purposes of using enable_if in the same manner is standard type traits such as is_arithmetic etc. The trait will be false by default, and I'd declare something to nominate types that should be seen to have that trait. I want it to follow inheritance; if B has been declared to be in my category, and C is derived from B, then C will also be in that category without needing to do anything more (though some way to turn it _off_ would be available). Can someone advise me on an easy way to structure this? Thanks, —John

6 10

retrieve data using associative property maps with boost::bimaps - failed
by Aniket Pugaonkar 10 Feb '14

10 Feb '14

Hi, I am facing compilation error in the following code. I do understand why the error is, but I could not find a good solution. Here is my code and question explained in detail *What I want to do:* I want to store a key- value pair where both key and its respective values is unique. But After I create a map, I want to use the VALUE and get the corresponding key. Essentially the best way is a bimap. So I do the following using associative property maps. *What I did:* 1. define a bimap (my_bimap ) 2. define associative property map for left view of bimap ( right_asso_bimap ) 3. define associative property map for right view of bimap ( left_asso_bimap ) 4. fill the bimap using *left* view associative property map. i.e. *use boost::put( left_asso_bimap, key, value )* 5. Now using *right* view associative property map, retrieve key for given value i.e. use *boost::get( right_asso_bimap, value )* My main motive is to use GET and PUT helper functions for insertion and retrieval from a bimap. Use PUT to insert in LEFT BIMAP. and Use GET to retrieve from RIGHT BIMAP. I know the error is because of non-const-ness of the iterators because of which I cannot de-reference using iterators. But what would be the alternative to this ? This link here explains how to define parameters for bimap in order for iterators to be mutable. http://www.boost.org/doc/libs/1_55_0/libs/bimap/doc/html/boost_bimap/the_tu… *But I get the error below: * In file included from main.cpp:2:0: /usr/local/include/boost/property_map/property_map.hpp: In instantiation of 'boost::associative_property_map<UniquePairAssociativeContainer>::value_type& boost::associative_property_map<UniquePairAssociativeContainer>::operator[](const key_type&) const [with UniquePairAssociativeContainer = boost::bimaps::views::list_map_view<boost::bimaps::relation::member_at::right, boost::bimaps::detail::bimap_core<int, boost::bimaps::list_of<long unsigned int>, mpl_::na, mpl_::na, mpl_::na> > boost::associative_property_map<UniquePairAssociativeContainer>::reference = const int&; boost::associative_property_map<UniquePairAssociativeContainer>::value_type = const int; boost::associative_property_map<UniquePairAssociativeContainer>::key_type = long unsigned int]': /usr/local/include/boost/property_map/property_map.hpp:357:54: required from 'Reference boost::get(const boost::put_get_helper<Reference, PropertyMap>&, const K&) [with PropertyMap = boost::associative_property_map<boost::bimaps::views::list_map_view<boost::bimaps::relation::member_at::right, boost::bimaps::detail::bimap_core<int, boost::bimaps::list_of<long unsigned int>, mpl_::na, mpl_::na, mpl_::na> > > Reference = const int&; K = int]' main.cpp:41:35: required from here /usr/local/include/boost/property_map/property_map.hpp:502:20: error: no match for 'operator[]' (operand types are 'boost::associative_property_map<boost::bimaps::views::list_map_view<boost::bimaps::relation::member_at::right, boost::bimaps::detail::bimap_core<int, boost::bimaps::list_of<long unsigned int>, mpl_::na, mpl_::na, mpl_::na> > >::C {aka boost::bimaps::views::list_map_view<boost::bimaps::relation::member_at::right, boost::bimaps::detail::bimap_core<int, boost::bimaps::list_of<long unsigned int>, *mpl_::na, mpl_::na, mpl_::na> >}' and 'const key_type {aka const long unsigned int}')* *return (*m_c)[k];* ^ Here my code. You can also see the code here on this website link:* http://coliru.stacked-crooked.com/a/59cbf2c564bf22b2 <http://coliru.stacked-crooked.com/a/59cbf2c564bf22b2>* #include <boost/bimap.hpp> #include <boost/property_map/property_map.hpp> #include <boost/bimap/property_map/set_support.hpp>#include <boost/bimap/list_of.hpp>#include <iostream> using namespace boost; int main() {typedef int vertex_descriptor_t;namespace bm = boost::bimaps;typedef bm::bimap< vertex_descriptor_t, bm::list_of<size_t> > vd_idx_bimap_t;typedef boost::associative_property_map<vd_idx_bimap_t::left_map> Lasso_vd_idx_bimap_t;typedef boost::associative_property_map<vd_idx_bimap_t::right_map> Rasso_vd_idx_bimap_t; // define bimap and assoc prop map for itvd_idx_bimap_t my_bimap;Lasso_vd_idx_bimap_t Lmy_asso_bimap(my_bimap.left );Rasso_vd_idx_bimap_t Rmy_asso_bimap(my_bimap.right); typedef typename vd_idx_bimap_t::value_type value_type; my_bimap.insert( value_type( 1, 100 ) ); my_bimap.insert( value_type( 2, 200 ) ); int z = 1; std::cout << "value = " << get ( my_bimap.left, z ) << std::endl; // prints correctly value = 100 // use left asso bimap for inserting to bimap boost::put( Lmy_asso_bimap, 3, 300 ); // correct // print bimap using *left view*for(auto t = my_bimap.left.begin(); t != my_bimap.left.end(); ++t) std::cout << t->first << " " << t->second << "\n"; int y = 2;*z **= boost::get( Lmy_asso_bimap, y ); // CORRECT OUTPUT for left view * std::cout << "value = " << z << std::endl; // Use right asso bimap to get key based on supplied value y = 100;*z = boost::get( Rmy_asso_bimap, y );* *// -->> ERROR HERE for right view* std::cout << "value = " << z << std::endl; // print map again. (*right view*)for(auto t = my_bimap.right.begin(); t != my_bimap.right.end(); ++t) std::cout << t->first << " " << t->second << "\n"; } Please let me know whether this is a potential bug, or the code semantics is incorrect. Or the current library cannot support this. ? Regards, Aniket Pugaonkar -- Thanks and regards, Aniket Pugaonkar

1 0

interprocess library deadlocked
by Hernán Leoni 10 Feb '14

10 Feb '14

Hi everyone, I'm using boost interprocess, and in some cases I get the interprocess library deadlocked, now I'm using internal timed locks, so, I get timeout exception Fortunately it is not that frequent, but it is an issue I need to resolve before going live, When this happens the shared memory cannot be used at all, so it needs to be removed and a new one must be created. I'm not sure yet why these internal mutexes are getting locked and never unlocked, it may be happening with some process being killed unexpectedly. I was wanting to see if anybody has already figured out which approach is better for this case. Thanks a lot, Hernan

1 0

Regarding post: Using Boost.Test in Iteration
by Deepa S 10 Feb '14

10 Feb '14

Hi Gennadiy/Gaurav, Wanted to check if there was any resolution to the error indicated in this post: http://lists.boost.org/boost-users/2010/06/59564.php I am running into a similar issue and would like to know how to resolve it. Thanks, Deepa

2 1

Attn: We need GSoC 2014 mentors for Boost!
by Niall Douglas 09 Feb '14

09 Feb '14

Dear Boost community, We are now just five days away from the closing date for Google Summer of Code 2014 registration. Last year's GSoC was a huge success, with Google funding work on Boost to the tune of $35,000 and paying over $8,000 in costs for three representatives of Boost to attend the GSoC mentor's summit at Google HQ. As part of filling in our application for 2014, we must supply to Google a list of potential GSoC mentors and potential GSoC projects for summer 2014. We do NOT want a repeat of 2012 when our application was rejected due to an insufficiently long list of prospective mentors and projects! At the time of writing, we have just *eight* prospective mentors, and we need more to be sure of being approved by Google! Therefore, if you think yourself able to mentor a student doing some work on Boost this summer, *please* consider adding a description of the proposed work item and your name to the list at https://svn.boost.org/trac/boost/wiki/SoC2014. If you want to know more about mentoring a Google Summer of Code funded student work before you nominate yourself, please feel free to ask on the main Boost developers mailing list boost(a)lists.boost.org. Thank you in advance for your time. Niall Douglas (Boost Google Summer of Code admin) Boris Schäling (Boost Google Summer of Code backup admin)

2 4

Boost.Asio ssl session reuse
by Krzysztof Trzepla 09 Feb '14

09 Feb '14

Hello, Is there a way to cache ssl session using Boost.Asio library, so that it can be later on reused with an abbreviated handshake? If so, I will appreciate any example. -- Regards, Krzysztof Trzepla

1 0

[Boost.Python] Wrapping a heterogeneous container
by Mario Lang 08 Feb '14

08 Feb '14

Hi. I have finally figured out how to (mostly) wrap a container of boost::variant<> in boost::python: http://blind.guru/boost_python-and-boost_variant.html The only problem left is the fact that I have to disable the use of reference semantics (proxies) in vector_indexing_suite. If I pass false for the NoProxy template parameter of vector_indexing_suite<>, I can no longer dereference container elements: >>> import bpv >>> bpv.make_vector()[0] Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: No Python class registered for C++ class boost::variant<a, b, boost::detail::variant::void_, ...> However, I have a converter registered with to_python_converter<> that handles extracting the proper Python object from a variant. This works if NoProxy is true. However, if NoProxy is true, container elements do not have reference semantics, so in-place modifications will be lost. To me, it also looks like the TypeError raise above is sort of bogus, since I actually used to_python_converter to register conversion for this particular type. So I guess there are different types of registries involved, but the message does not indicate which registry is did refer to. Does anyone know if I can enable reference semantics for a heterogeneous container wrapped with indexing_suite? -- CYa, ⡍⠁⠗⠊⠕

1 0

Apology: RE: FileSystem: crash on OSX 10.8 with create_directory
by Tim Burgess 08 Feb '14

08 Feb '14

Hi, I must apologise for the stupidity of this question - if I'd have surrounded the call with a try/catch block I'd have figured it out sooner, so it's my own bad coding. Now all I need to figure out is how to programmatically create a directory with admin rights to get around the permission denied exception when trying to create files/directories within /library/application support/ on the Mac. Best wishes. Tim Burgess From: Boost-users [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Tim Burgess Sent: 07 February 2014 16:32 To: boost-users list Subject: [Boost-users] FileSystem: crash on OSX 10.8 with create_directory Hi, My app crashes out when I run the following: boost::filesystem::path myPath = wxStandardPaths::Get().GetConfigDir().ToStdWstring(); if (myPath.has_filename()) { myPath.remove_filename(); } // Add the company name and check for directory existence myPath /=wstrRBCompanyName; if (!boost::filesystem::exists(myPath)) { // The following test displays the path I'd expect to see (/library/Raised Bar in my case) wxMessageBox( myPath.native(), wstrErrorTitle, wxOK | wxICON_EXCLAMATION); // Create the required directory - displays a message box indicating deletion of a lock file here and the app exits boost::filesystem::create_directory(myPath); } This code appears to work fine on Windows, but fails on OSX 10.8. I should point out that I'm a blind programmer and I'm struggling to get Apple's VoiceOver utility to interact in a useful manner with Xcode 5's debugger and that's why I'm using a wxMessageBox to try and track down my failure. Best wishes. Tim

1 0