August 2014 - Boost-users - lists.preview.boost.org

Allocation/deallocations during boost serialization (tracking help?)
by miles_c＠verizon.net 12 Aug '14

12 Aug '14

1 0

asio::ip::tcp iostream wrong byte count read for last packet
by Steve Coleman 12 Aug '14

12 Aug '14

I just started out with Boost and was writing a little binary file transfer app and ran into a little problem, so I would appreciate if someone could kindly point out what I am doing wrong here. My problem is in getting the correct byte count read in the final packet received. My last frame always returns the size of the buffer, not the number of bytes read into the buffer. Isn't iostream::gcount(() meant for this? If not, what is the correct 'Boost' way of doing this? int spool_binary_data() { boost::asio::ip::tcp::endpoint dataServerEndpoint(boost::asio::ip::tcp::v4(), PMMS_TRANSFER_PORT_NUMBER); boost::asio::ip::tcp::acceptor acceptor(dataServer, dataServerEndpoint); boost::asio::ip::tcp::iostream dataServerStream; acceptor.accept(*dataServerStream.rdbuf()); char buffer[2048]; std::streamsize nbytes = sizeof(buffer); FILE * pFile = fopen ("binary.out","w"); // count = getavailable(this->native_socket) ?? // stream->rdbuf()->available() ?? while ( dataServerStream.read((char*)&buffer, nbytes) ) { int bytes_read = dataServerStream.gcount(); // always 2048 std::cout << "bytes read " << bytes_read << std::endl; fwrite(buffer,1,bytes_read,pFile); } dataServerStream.close(); fclose(pFile); }

2 3

Basic question about using remove_edge() in boost graph library
by Yi-Ping Huang 11 Aug '14

11 Aug '14

Dear boost-users: I just start learning boost graph library and have a basic problem on using the remove_edge function in boost graph library. I would like to remove an edge in a multigraph. For a graph with two edges connect vertice 0 and 1, I would like to remove one of them, but kept the other. According to the user guide, remove_edge(u ,v , g) removes all occurrences of (u ,v). So I should use remove_edge(e ,g) instead. Here, e is a valid edge descriptor. For a single graph, g, I am able to perform both remove_edge(u ,v , g) and remove_edge(e ,g) operation. However, when I want to generalize the implementation to fit my need by putting graphs in a vector container, I got segmentation fault for remove_edge(e ,graph_list[0]). I really want to make remove_edge(e,g) and vector container work at the same time. So any suggestion that can help my bypass this difficulty is appreciated. Thanks a lot!! Yi-Ping *************************Here is the complete code************************* #include <iostream> #include <utility> #include <algorithm> #include <vector> #include "boost/graph/graph_traits.hpp" #include "boost/graph/adjacency_list.hpp" using namespace boost; typedef adjacency_list<vecS, vecS, undirectedS> UndirectedGraph; typedef boost::graph_traits<UndirectedGraph>::edge_iterator edge_iterator; int graph_show(UndirectedGraph &g); int main(int argc, char *argv[]) { UndirectedGraph g; typedef boost::graph_traits<UndirectedGraph>::edge_descriptor edge_descriptor; edge_descriptor ed; std::vector<edge_descriptor> edge_list; std::vector<std::vector<edge_descriptor> > graph_edge_list; std::vector<UndirectedGraph> graph_list; int nb=0; int Nl=4; bool inserted; while(nb<Nl) { tie(ed,inserted)=add_edge(nb,nb+1,g); edge_list.push_back(ed); tie(ed,inserted)=add_edge(nb,nb+1,g); edge_list.push_back(ed); graph_edge_list.push_back(edge_list); nb=nb+1; graph_list.push_back(g); } std::cout<<"size of the graph vector is: "<<graph_list.size()<<std::endl; remove_edge(graph_edge_list[0][0],graph_list[0]);//This is where the problem shows. //I got Segmentation fault (core dumped) //remove_edge(0,1,graph_list[0]); /*Remove edges by assigning vertices works fine, but that is not what I need.*/ for (int ig = 0; ig < Nl; ++ig) { std::cout<<"graph#"<<ig<<std::endl; std::cout<<"Size of edge_list is: "<<graph_edge_list[ig].size()<<std::endl; graph_show(graph_list[ig]); } std::cout<<"Success"<<std::endl; return 0; } int graph_show(UndirectedGraph &g) { std::cout<<"Number of edges is : "<<boost::num_edges(g)<<std::endl; std::cout<<"Number of vertices is : "<<boost::num_vertices(g)<<std::endl; std::pair<edge_iterator,edge_iterator> ei=edges(g); for (edge_iterator edge_iter = ei.first; edge_iter!=ei.second; ++edge_iter) { std::cout<<"("<< boost::source(*edge_iter,g)<<","<<boost::target(*edge_iter,g)<<")"<<std::endl; } typedef boost::graph_traits<UndirectedGraph>::vertex_iterator iter_v; std::cout<<"vertices(g)={ "; for (std::pair<iter_v,iter_v> p = vertices(g); p.first != p.second; ++p.first) { std::cout<< *p.first; std::cout<<" "; } std::cout<<"}"<<std::endl; return 0; }

1 0

[String algorithms] User defined finders and predicates
by Aaron Levy 11 Aug '14

11 Aug '14

Are there good examples of writing user defined finders and predicates for functions such as find_token? Aaron

1 0

Boost 1.56.0 has been released
by Marshall Clow 11 Aug '14

11 Aug '14

Release 1.56.0 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 one new library and numerous enhancements and bug fixes for existing libraries. === Modularization === Boost version control has migrated to a system using git submodules. This shouldn't make too much of a difference to users, although the directory structure is now a bit different. Parts of some libraries have been moved into different modules, and several new modules have been extracted from existing code. All header paths should remain the same. The new modules are: • Assert: Customizable assert macros. Maintained by Peter Dimov. • Core: Core utilities used by other libraries, with minimal dependencies. Maintained by Peter Dimov, Glen Fernandes and Andrey Semashev. • Lexical_Cast: General literal text conversions, such as an int represented a string, or vice-versa, from Kevlin Henney. • Throw_Exception: A common infrastructure for throwing exceptions from Boost libraries, from Emil Dotchevski. • Winapi: Windows API declarations without <windows.h>, for internal Boost use. === New Libraries === • Align: Memory alignment functions, allocators, and adaptors, from Glen Fernandes. • Type_Index: Runtime/Compile time copyable type info, from Antony Polukhin. For details, including download links, see http://www.boost.org/users/news/version_1.56.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.56.0/ 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 Vladimir Prus Rene Rivera Marshall Clow Eric Niebler Daniel James Beman Dawes

8 10

[asio] multiple simultaneous async_read calls
by bbxiong 11 Aug '14

11 Aug '14

Hello, all, If i write some code like this: boost::asio::async_read(socket_, bosot::asio::buffer(buffer1_.data(), len1, handler1); boost::asio::async_read(socket_, boost::asio::buffer(buffer2_.data(), len2, handler2); Will asio guarantee len1 bytes received by the first async_read, then schedule async_read2? or the result is undefined(like several bytes filled into buffer1, then next several bytes into buffer, then next several bytes into buffer1)? if the result is undefined, why asio don't add a check here? Thanks all in advance!

5 8

[Boost.Thread] Compile error: boost::promise<T>::set_value(const T&) doesn't exist
by Rob Desbois 10 Aug '14

10 Aug '14

Hi all, I'm having problems compiling with Boost.Thread's futures I can't seem to pass anything but a primitive type into make_ready_future. I've had problems with other parts of Thread (packaged_task, promise, unique/shared_future) that have produced horrendously unhelpful compile errors. Here is a minimal testcase: #include <boost/thread/future.hpp> struct foo { foo(int i_): i(i_) {} int i; }; int main() { // A const future ref isn't much use, but I needed to prove // the problem wasn't me trying to copy a unique_future const boost::unique_future<foo>& fut = boost::make_ready_future( foo(42) ); } With `BOOST_THREAD_USES_MOVE` defined before including the Boost.Future header I get the following error with gcc 4.8.2 and Boost 1.55 (full output at http://pastebin.com/0sePWBWr) ../../deps/boost/include/boost/thread/future.hpp:3634:5: error: no matching function for call to ‘boost::promise<foo>::set_value(const foo&)’ p.set_value(boost::forward<future_value_type>(value)); ^ There seems to be no overload of promise::set_value() that takes a const lvalue reference. Looking at `promise` and `future_traits` in `future.hpp` it seems that the const lvalue ref overload will only exist when `BOOST_NO_CXX11_RVALUE_REFERENCES` is undefined. That makes no sense to me however...surely the const lvalue ref overload is needed precisely when there are no rvalue references? (Note this happens even if I pass a mutable lvalue ref to `make_ready_future()`). If I don't define `BOOST_THREAD_USES_MOVE` it fails compilation with the following error (full output at http://pastebin.com/jBwiJLeC) ../../deps/boost/include/boost/thread/detail/move.hpp:183:54: error: no matching function for call to boost::unique_future<foo>::unique_future(boost::unique_future<foo>)’ #define BOOST_THREAD_MAKE_RV_REF(RVALUE) RVALUE.move() ^ Have I missed something? I'm unable to switch to C++11 mode unfortunately, but this seems such a big problem I can only assume I've done something wrong. I still get similar compile errors trying with Clang 3.4, and also with Boost 1.54 (g++ or Clang). -- Rob Desbois http://theotherbranch.wordpress.com/

2 1

[Boost.Range] Filtering elements at even position
by Arindam Mukherjee 10 Aug '14

10 Aug '14

I am trying to create a range consisting of elements in a container at only even indexes. Is there a way to write something like: vec | boost::adaptors::indexed(0) | some_adaptor_to_choose_even_indexes I tried with boost::adaptors::filtered, but the index information is only present in iterators of the generated range, not in its value_type so it is not available in chained adaptors. - Arindam

2 1

Boost 1.56.0 compilation error in iterator_range
by gast128 10 Aug '14

10 Aug '14

I get a compilation error with vc10, iterator_range and a (const) unordered_map (the beta candidate 2 was still ok I think): #include "stdafx.h" #include <boost/range/iterator_range.hpp> #include <boost/unordered_map.hpp> int _tmain(int /*argc*/, _TCHAR* /*argv*/[]) { typedef boost::unordered_map<int, int> Container; typedef Container::const_iterator ContainerIterator; typedef boost::iterator_range<ContainerIterator> ContainerIteratorRange; const Container cnt; ContainerIteratorRange rng(cnt.cbegin(), cnt.cend()); return 0; } This gives C2248: 'boost::unordered::iterator_detail::c_iterator<Node,ConstNodePointer>::iterator' cannot access private typedef declared in class etc. (note had to cut due to 'you have lines longer than 80 characters. Fix that.' in Gmane)

2 3

[boost] [1.55] numerous warnings with gcc 4.8.3 on Linux
by Marius Lazer 08 Aug '14

08 Aug '14

All the warnings are similar to this (warning: typedef âboost_concept_check185â locally defined but not used [-Wunused-local-typedefs]): ./boost/range/algorithm/equal.hpp: In function âbool boost::range::equal(const SinglePassRange1&, const SinglePassRange2&, BinaryPredicate)â: ./boost/concept/detail/general.hpp:71:20: warning: typedef âboost_concept_check185â locally defined but not used [-Wunused-local-typedefs] BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/preprocessor/cat.hpp:29:34: note: in definition of macro âBOOST_PP_CAT_Iâ # define BOOST_PP_CAT_I(a, b) a ## b ^ ./boost/concept/detail/general.hpp:71:7: note: in expansion of macro âBOOST_PP_CATâ BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/concept/assert.hpp:44:5: note: in expansion of macro âBOOST_CONCEPT_ASSERT_FNâ BOOST_CONCEPT_ASSERT_FN(void(*)ModelInParens) ^ ./boost/range/concepts.hpp:92:45: note: in expansion of macro âBOOST_CONCEPT_ASSERTâ #define BOOST_RANGE_CONCEPT_ASSERT( x ) BOOST_CONCEPT_ASSERT( x ) ^ ./boost/range/algorithm/equal.hpp:185:13: note: in expansion of macro âBOOST_RANGE_CONCEPT_ASSERTâ BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange1> )); ^ ./boost/concept/detail/general.hpp:71:20: warning: typedef âboost_concept_check186â locally defined but not used [-Wunused-local-typedefs] BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/preprocessor/cat.hpp:29:34: note: in definition of macro âBOOST_PP_CAT_Iâ # define BOOST_PP_CAT_I(a, b) a ## b ./boost/concept/detail/general.hpp:71:7: note: in expansion of macro âBOOST_PP_CATâ BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/concept/assert.hpp:44:5: note: in expansion of macro âBOOST_CONCEPT_ASSERT_FNâ BOOST_CONCEPT_ASSERT_FN(void(*)ModelInParens) ^ ./boost/range/concepts.hpp:92:45: note: in expansion of macro âBOOST_CONCEPT_ASSERTâ #define BOOST_RANGE_CONCEPT_ASSERT( x ) BOOST_CONCEPT_ASSERT( x ) ^ ./boost/range/algorithm/equal.hpp:186:13: note: in expansion of macro âBOOST_RANGE_CONCEPT_ASSERTâ BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange2> )); Thanks, Marius Marius S. Lazer ICAP North America Inc. Harborside Financial Center 1100 Plaza 5 Jersey City, NJ 07311-4996 Office: 212-815-7470 Email: Marius.Lazer(a)us.icap.com ********************************************************************** This communication and all or some of the information contained therein may be confidential and is subject to our Terms and Conditions. If you have received this communication in error, please destroy all electronic and paper copies and notify the sender immediately. Unless specifically indicated, this communication is not a confirmation, an offer to sell or solicitation of any offer to buy any financial product, or an official statement of ICAP or its affiliates. Non-Transactable Pricing Terms and Conditions apply to any non-transactable pricing provided. All terms and conditions referenced herein available at www.icapterms.com. Please notify us by reply message if this link does not work. ********************************************************************** ICAP's 21st global annual Charity Day – took place Tuesday 3 December 2013. Together we raised £9.5 million (US$15.5 million), totalling £110 million since 1993. www.icapcharityday.com --------------------------------------------------------------------------------------- This email has been scanned for email related threats and delivered safely by Mimecast. For more information please visit http://www.mimecast.com ---------------------------------------------------------------------------------------

1 0