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[gil io_new] Problem writing a compressed jpeg
by Olivier Tournaire 07 Jun '10

07 Jun '10

Hi all, I am currently trying to write a compressed jpeg image without any success. Here is my code: #include <string> #include <boost/mpl/vector.hpp> #include <boost/gil/gil_all.hpp> #include <boost/gil/extension/io_new/tiff_read.hpp> #include <boost/gil/extension/io_new/tiff_write.hpp> #include <boost/gil/extension/io_new/jpeg_read.hpp> #include <boost/gil/extension/io_new/jpeg_write.hpp> using namespace std; using namespace boost; using namespace gil; int main(int argc, char** argv) { string base_image_path(argv[1]); string output_image_path(argv[2]); string output_compressed_image_path(argv[3]); typedef mpl::vector< rgb8_image_t, rgb16_image_t > rgb_image_types; typedef any_image<rgb_image_types> any_image_type; typedef any_image_type::view_t any_view_type; // Read tiff image image_read_info< tiff_tag > info = read_image_info( base_image_path , tiff_tag() ); any_image_type input_image; read_image(base_image_path.c_str(), input_image, tiff_tag()); write_view(output_image_path.c_str(), view(input_image), jpeg_tag()); image_write_info< jpeg_tag > compressed_jpeg_info; compressed_jpeg_info._quality = 30; //compressed_jpeg_info._dct_method = jpeg_dct_method::fastest; write_view(output_compressed_image_path.c_str(), view(input_image), compressed_jpeg_info); } Could you please help me ? Regards, Olivier

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[utf] global fixture problem
by Olaf Peter 07 Jun '10

07 Jun '10

Hi, in the following snippet I get the compiler error: utf_global_fixture.cpp: In member function ‘void my_test1::test_method()’: utf_global_fixture.cpp:19: error: ‘check’ was not declared in this scope utf_global_fixture.cpp:20: error: expected ‘;’ before ‘do’ // Boost.Test #define BOOST_TEST_MODULE Unit_test_example_09 #include <boost/test/unit_test.hpp> // STL #include <iostream> struct MyConfig { MyConfig() { std::cout << "global setup part1\n"; } ~MyConfig() { std::cout << "global teardown part1\n"; } bool check() const { return true;} }; // structure MyConfig is used as a global fixture - it's invoked pre and post any testing is performed BOOST_GLOBAL_FIXTURE( MyConfig ) BOOST_AUTO_TEST_CASE( my_test1 ) { BOOST_REQUIRE( check() ) BOOST_CHECK( true ); } isn't the member access like the test case/module fixture (as I did read in the docs)? Thanks, Olaf

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[BGL] Distributed Dijkstra vertex_iterator
by Bruno Santos 07 Jun '10

07 Jun '10

Hi all, I'm fairly new to boost so please bear my ignorance. I'm trying to implement the example of the distributed Dijkstra using the Parallel BGL and I'm having problems when iterating through the distance map. This is the code. Just updated the dijkstra_example.cpp with the Parallel BGL Dijkstra instructions. #include <boost/config.hpp> #include <iostream> #include <fstream> #include <stdio.h> #include <iomanip> #include <vector> #include <boost/graph/use_mpi.hpp> #include <boost/graph/distributed/mpi_process_group.hpp> #include <boost/graph/dijkstra_shortest_paths.hpp> #include <boost/graph/distributed/adjacency_list.hpp> using namespace boost; using boost::graph::distributed::mpi_process_group; int main(int argc, char* argv[]) { boost::mpi::environment env(argc,argv); typedef adjacency_list<listS, distributedS<mpi_process_group, vecS>, directedS, no_property, // Vertex properties property<edge_weight_t, int> // Edge properties > graph_t; typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor; typedef graph_traits < graph_t >::edge_descriptor edge_descriptor; typedef std::pair<int, int> Edge; const int num_nodes = 5; enum nodes { A, B, C, D, E }; char name[] = "ABCDE"; Edge edge_array[] = { Edge(A, C), Edge(B, B), Edge(B, D), Edge(B, E), Edge(C, B), Edge(C, D), Edge(D, E), Edge(E, A), Edge(E, B) }; int weights[] = { 1, 2, 1, 2, 7, 3, 1, 1, 1 }; int num_arcs = sizeof(edge_array) / sizeof(Edge); #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 graph_t g(num_nodes); property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g); for (std::size_t j = 0; j < num_arcs; ++j) { edge_descriptor e; bool inserted; tie(e, inserted) = add_edge(edge_array[j].first, edge_array[j].second, g); weightmap[e] = weights[j]; } #else graph_t g(edge_array, edge_array + num_arcs, weights, num_nodes); property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g); #endif std::vector<vertex_descriptor> p(num_vertices(g)); std::vector<int> d(num_vertices(g)); vertex_descriptor s = vertex(A, g); #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 // VC++ has trouble with the named parameters mechanism property_map<graph_t, vertex_index_t>::type indexmap = get(vertex_index, g); dijkstra_shortest_paths(g, s, &p[0], &d[0], weightmap, indexmap, std::less<int>(), closed_plus<int>(), (std::numeric_limits<int>::max)(), 0, default_dijkstra_visitor()); #else dijkstra_shortest_paths (g, s, predecessor_map( make_iterator_property_map(p.begin(), get(vertex_index, g))). distance_map( make_iterator_property_map(d.begin(), get(vertex_index, g))) ); #endif std::cout << "distances and parents:" << std::endl; graph_traits < graph_t >::vertex_iterator vi, vend; for (tie(vi, vend) = vertices(g); vi != vend; ++vi) { std::cout << "distance(" << name[*vi] << ") = " << d[*vi] << ", "; std::cout << "parent(" << name[*vi] << ") = " << name[p[*vi]] << std:: endl; } std::cout << std::endl; return 0; } The compiler line I'm using is: mpic++ -I/usr/include/boost/graph/distributed/ -I/usr/include/boost/ -L/usr/lib/ /usr/lib/libboost_mpi-mt.so /usr/lib/libboost_serialization-mt.so /usr/lib/libboost_graph_parallel-mt.so /usr/lib/libboost_system-mt.so dij.cpp -o dijkstr and the error is: In file included from /usr/include/c++/4.4/backward/hash_set:59, from /usr/include/boost/graph/adjacency_list.hpp:25, from /usr/include/boost/graph/distributed/adjacency_list.hpp:18, from dij.cpp:11: /usr/include/c++/4.4/backward/backward_warning.h:28:2: warning: #warning This file includes at least one deprecated or antiquated header which may be removed without further notice at a future date. Please use a non-deprecated interface with equivalent functionality instead. For a listing of replacement headers and interfaces, consult the file backward_warning.h. To disable this warning use -Wno-deprecated. dij.cpp: In function ‘int main(int, char**)’: dij.cpp:74: error: no match for ‘operator[]’ in ‘name[((boost::iterator_facade<boost::transform_iterator<boost::detail::parallel::global_descriptor<long unsigned int>::generator, boost::counting_iterator<long unsigned int, boost::use_default, boost::use_default>, boost::use_default, boost::use_default>, boost::detail::parallel::global_descriptor<long unsigned int>, boost::random_access_traversal_tag, boost::detail::parallel::global_descriptor<long unsigned int>, long int>*)(& vi))->boost::iterator_facade<I, V, TC, R, D>::operator* [with Derived = boost::transform_iterator<boost::detail::parallel::global_descriptor<long unsigned int>::generator, boost::counting_iterator<long unsigned int, boost::use_default, boost::use_default>, boost::use_default, boost::use_default>, Value = boost::detail::parallel::global_descriptor<long unsigned int>, CategoryOrTraversal = boost::random_access_traversal_tag, Reference = boost::detail::parallel::global_descriptor<long unsigned int>, Difference = long int]()]’ dij.cpp:74: error: no match for ‘operator[]’ in ‘d[((boost::iterator_facade<boost::transform_iterator<boost::detail::parallel::global_descriptor<long unsigned int>::generator, boost::counting_iterator<long unsigned int, boost::use_default, boost::use_default>, boost::use_default, boost::use_default>, boost::detail::parallel::global_descriptor<long unsigned int>, boost::random_access_traversal_tag, boost::detail::parallel::global_descriptor<long unsigned int>, long int>*)(& vi))->boost::iterator_facade<I, V, TC, R, D>::operator* [with Derived = boost::transform_iterator<boost::detail::parallel::global_descriptor<long unsigned int>::generator, boost::counting_iterator<long unsigned int, boost::use_default, boost::use_default>, boost::use_default, boost::use_default>, Value = boost::detail::parallel::global_descriptor<long unsigned int>, CategoryOrTraversal = boost::random_access_traversal_tag, Reference = boost::detail::parallel::global_descriptor<long unsigned int>, Difference = long int]()]’ /usr/include/c++/4.4/bits/stl_vector.h:610: note: candidates are: typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::reference std::vector<_Tp, _Alloc>::operator[](size_t) [with _Tp = int, _Alloc = std::allocator<int>] /usr/include/c++/4.4/bits/stl_vector.h:625: note: typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::const_reference std::vector<_Tp, _Alloc>::operator[](size_t) const [with _Tp = int, _Alloc = std::allocator<int>] dij.cpp:75: error: no match for ‘operator[]’ in ‘name[((boost::iterator_facade<boost::transform_iterator<boost::detail::parallel::global_descriptor<long unsigned int>::generator, boost::counting_iterator<long unsigned int, boost::use_default, boost::use_default>, boost::use_default, boost::use_default>, boost::detail::parallel::global_descriptor<long unsigned int>, boost::random_access_traversal_tag, boost::detail::parallel::global_descriptor<long unsigned int>, long int>*)(& vi))->boost::iterator_facade<I, V, TC, R, D>::operator* [with Derived = boost::transform_iterator<boost::detail::parallel::global_descriptor<long unsigned int>::generator, boost::counting_iterator<long unsigned int, boost::use_default, boost::use_default>, boost::use_default, boost::use_default>, Value = boost::detail::parallel::global_descriptor<long unsigned int>, CategoryOrTraversal = boost::random_access_traversal_tag, Reference = boost::detail::parallel::global_descriptor<long unsigned int>, Difference = long int]()]’ dij.cpp:75: error: no match for ‘operator[]’ in ‘p[((boost::iterator_facade<boost::transform_iterator<boost::detail::parallel::global_descriptor<long unsigned int>::generator, boost::counting_iterator<long unsigned int, boost::use_default, boost::use_default>, boost::use_default, boost::use_default>, boost::detail::parallel::global_descriptor<long unsigned int>, boost::random_access_traversal_tag, boost::detail::parallel::global_descriptor<long unsigned int>, long int>*)(& vi))->boost::iterator_facade<I, V, TC, R, D>::operator* [with Derived = boost::transform_iterator<boost::detail::parallel::global_descriptor<long unsigned int>::generator, boost::counting_iterator<long unsigned int, boost::use_default, boost::use_default>, boost::use_default, boost::use_default>, Value = boost::detail::parallel::global_descriptor<long unsigned int>, CategoryOrTraversal = boost::random_access_traversal_tag, Reference = boost::detail::parallel::global_descriptor<long unsigned int>, Difference = long int]()]’ /usr/include/c++/4.4/bits/stl_vector.h:610: note: candidates are: typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::reference std::vector<_Tp, _Alloc>::operator[](size_t) [with _Tp = boost::detail::parallel::global_descriptor<long unsigned int>, _Alloc = std::allocator<boost::detail::parallel::global_descriptor<long unsigned int> >] /usr/include/c++/4.4/bits/stl_vector.h:625: note: typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::const_reference std::vector<_Tp, _Alloc>::operator[](size_t) const [with _Tp = boost::detail::parallel::global_descriptor<long unsigned int>, _Alloc = std::allocator<boost::detail::parallel::global_descriptor<long unsigned int> >] The boost version I'm using is 1.40.0 in a Ubuntu Machine. If anyone could help me I would be grateful :) Thanks, Bruno Santos

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[utf] handling 'gold' files
by Olaf Peter 07 Jun '10

07 Jun '10

Hi, what is the best way to give a test executable (BOOST_AUTO_TEST_CASE, Test suite with automated registration) a path to 'gold' files and use them? Thanks, Olaf

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Fwd: boost::thread and corresponding stack array
by Aditya Arora 07 Jun '10

07 Jun '10

I'd like to use boost threads, if possible, in an upcoming project, just for the sake of portability. The problem is that boost threads seem a bit unwieldy when it comes to quickly creating multiple threads. Since the thread object constructor is what actually launches the thread, you can't simply create an array of thread objects on the stack, since each thread is only launched when the constructor is passed a functor. Therefore, if you want an array of threads, you need to allocate each thread object individually on the heap, like: boost::thread* thr[SIZE]; for (int i = 0; i < SIZE; ++i) thr[i] = new boost::thread(functor); Then of course, you need to iterate through the array later and call delete on each thread object. It's much simpler to do this with plain old pthreads, since pthreads need to be explicitly started by calling pthread_create, so you can create an array of pthread structs on the stack, and then call pthread_create on each one, without having to allocate/free objects on the heap. It would be really nice if boost threads simply had a start() member function, or something, so that you could do something like: boost::thread thr[SIZE]; for (int i =0 ; i < SIZE: ++i) thr[i].start(functor); Does anyone know the design considerations that went into creating boost threads, and why the designers chose to have the constructor the only way to launch a new thread? Aditya

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Thread can not run concurrently with bind parameter
by coofucoo zhang 07 Jun '10

07 Jun '10

Hi All: It may be a simple question, but I have no idea now. So I want to post my question with you. Maybe you can help, thank you. It is about boost thread. I want to create a thread and pass a parameter to it. I found there are 2 ways in boost thread, they are: using bind, like *boost::thread thrd(boost::bind(&helloworld, "Bob"));* *thrd.join();* or construct a structure and do the following: *boost::thread thrd(helloworld("Bob"));* *thrd.join();* It works, really, like the demo code shown. But After I run 2 threads, I found 2 thread can not run concurrently. The second thread will blocked by the first thread. If the first thread never exit, the second thread never run. It is a very funny problem. But I really do not know what happen. Does anyone know about this topic? Thank you very much. -- With regards. Coofucoo Zhang

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[intrusive] join lists
by Tim Blechmann 06 Jun '10

06 Jun '10

hi all, is there a way to join two instances of boost.intrusive in constant time? thanks, tim

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[variant] newbie Q: cannot visit variant variable: "no matching function for call to apply_visitor ..."
by Riccardo Murri 06 Jun '10

06 Jun '10

Hello, I'm getting the following error when I try to compile the attached C++ source (repetitions of "boost::detail::variant::void_" omitted for clarity):: $ g++ variant_no_matching_function_call.cc variant_no_matching_function_call.cc: In member function ‘size_t Waterfall::Processor::step()::_row_size::operator()(boost::variant<Waterfall::Processor::SparseRow*, Waterfall::Processor::DenseRow*, boost::detail::variant::void_, ..., boost::detail::variant::void_>&)’: variant_no_matching_function_call.cc:47: error: no matching function for call to ‘apply_visitor(Waterfall::Processor::step()::__row_size, boost::variant<Waterfall::Processor::SparseRow*, Waterfall::Processor::DenseRow*, boost::detail::variant::void_, ..., boost::detail::variant::void_>&)’ I'm aware that the attached sample could be better handled by simple polymorphism, but it is the shortest excerpt from my real code that reproduces the problem. I'm getting the same error each time I try to "apply_visitor", so there must be something wrong in the way I'm using it... Thank you very much for any suggestions! I'm using g++ 4.4 and Boost.Variant 1.40 from the native Ubuntu 10.04 packages. Best regards, Riccardo -- Riccardo Murri, Hadlaubstr. 150, 8006 Zürich (CH)

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[phoenix][lambda] lambda to phoenix translation: get sig (signature) from actor
by alfC 05 Jun '10

05 Jun '10

hi, what is the translation of boost.lambda typename LambdaExp::template sig<tuple<InputType> >::type in Boost.Phoenix? my best try was: actor<LambdaExp>::result< vector<InputType> >::type but it doesn't compile. Thank you, Alfredo

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[Program Options] Requiring command-line options
by Jeremy Abramson 05 Jun '10

05 Jun '10

Heya! I just thinking about switching from simpleOpt to BoostPO for command line handling, mainly because of its support of configuration files. This may be a stupid question, but I haven't seen anything about making a command line parameter *required*. You'd think this is a pretty common thing, but I didn't see any mention of it in the tutorials or anything. I guess I could just make certain parameters default -1/NULL or something, and then test at the end if they're still equal to that, but that seems a bit ugly. Is there built in support (a flag in the "add_options" function or something) for making certain parameters required? Thanks a lot!

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