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[fusion]Is it possible to wrap a function template into a function object?
by someguy 22 Aug '11

22 Aug '11

If there is a function template: template<typename T> T f(T t); then f is not a type and cannot be passed to fusion::for_each() as the second argument. But I can't write fusion::for_each(someSequence,&f<SomeType>) either since elements of someSequence has different types. While I can write f as a functor fo struct fo{ template<typename T> T operator()(T t); }; and call fusion::for_each(someSequence,fo()), sometimes I need to use function templates in libraries ( say, I have a fusion::vector whose elements are ranges ) and the only solution seems to be writing a lot of functors to wrap the function templates. I tried to find a wrapper class template that can wrap arbitary function templates to functors in boost but I didn't find any. Then I tried to write such a wrapper using constructs like template<template<typename T0> class F>struct temp_fun_1; but the code made my MSVC2008 compiler crash(really!). Is there such a wrapper in boost or any other library, or is it even possible? -- View this message in context: http://boost.2283326.n4.nabble.com/fusion-Is-it-possible-to-wrap-a-function… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Containers Review Result] Boost.Containers is accepted into Boost.
by John Maddock 22 Aug '11

22 Aug '11

This is to announce that the Containers library by Ion Gaztanaga has been accepted into Boost. There were 11 positive reviews and one negative, many making the same points (see summary below). Acceptance is therefore conditional on Ion improving the documentation as the reviewers requested. Review comments summary: ~~~~~~~~~~~~~~~~~~~~~~~~ * Needs a better introduction/overview/tutorial in the docs: # what are stateful allocators, what's currently supported in this area, how is it supported, does it have performance implications. # Needs overview of the new containers - stable_vector, flat_* etc. # Needs description of recursive containers and why this library supports them but not C++03 containers. # Needs to justify why this library and not the std one (probably by mention of the above). * Make clear in the docs (if not already) what the default allocator is. * Make allocator template parameter name consistent. * Add basic_string::shrink_to_fit member function (from C++11). * Typo in range insertion docs (first/last vs i/j) * vector<bool> behavior needs to be documented (and justified either which way). * Need to document conformance to C++0x container requirements, plus use (or not) of new C++0x features such as std::allocator_traits. * Missing documentation for some deque member functions. * Missing Returns/Effects,Complexity or Throws. (ex: after No.23 in basic_string) * The "Acknowledgements" page is currently empty. There are various (c) notices in the source referring to sources from which parts of the code may have come. This page should clarify these sources, including any cases where the original code has now all been replaced, and assert that the licenses are all in order. It should also point out the history of the code in Boost, i.e. that parts were previously in Boost.Interprocess, so that anyone with previous exposure to the Interprocess containers is not confused. * There are some comments that the organisation of the docs makes it unnecessarily hard to jump directly to the info you want. Requests for additional features: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * Consider implementing std::forward_list from C++0x. * Consider Boost.Range interoperability and/or range insert support. * Make the flat_* containers container adapters - so that a) the user can choose the underlying implementation and b) they can shoot themselves in the foot if they want to by manipulating the underlying container (mostly for efficient loading of data). Alternatively, provide some other interface enhancements to try to meet most of the use cases given. * Efficient construction of ordered containers from already sorted data. * Investigate Clang's Libc++ std lib performance tests. John Maddock Containers review manager. PS: Ion: if you need any help with quickbook/docbook and AutoIndex ping me and I'll see what I can do to help - there are all sorts of parameters that can be used to tweak the appearance etc.

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Problems matching parantheses in a string using boost::regex 1.42.0 on a amd64 debian system
by Simon Hoerder 22 Aug '11

22 Aug '11

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA224 Hi, I'm fairly new to boost libraries but searched the documentation and googled for an answer to my problem but couldn't come up with something. Please bear with me. I am using boost::regex (version 1.42.0 on debian amd64 machine) to parse a vhdl-like file. To this end, I am trying to use the regular expression boost::regex("^SIGNAL ([A-Z0-9_]*?): STD_LOGIC_VECTOR$ ([0-9]*?) DOWNTO ([0-9]*?)$;$"); to match strings like: SIGNAL W07: STD_LOGIC_VECTOR( 255 DOWNTO 0); My problem is that matching those parantheses in the string doesn't work - - I've tested the regexp under perl and it works fine but boost::regexp and C++ works only if I remove the brackets from the string and from the regular expression. Issues I observed & tested: 1) '$' ... '$' no match but g++ complains about an unknown escape sequence '\)'. 1a) Using '$' ... ')' doesn't match. (I would have expected an exception to be thrown but none whatsoever.) 2) '0x28' ... '0x29' doesn't match. (0x28 = ASCII '(', 0x29 = ASCII ')') 3) '\Q(\E' ... '\Q)\E' no match but g++ complains about an unknown escape sequence '\Q'. 4) If I try to match only one of the brackets and remove the other from the string & regex I get one of the following: '\(' ... gives me: terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::regex_error> >' what(): Found a closing ) with no corresponding openening parenthesis. The error occured while parsing the regular expression fragment: '?([0-9]*?)>>>HERE>>>);$'. ... '$' gives me: terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::regex_error> >' what(): Unmatched marking parenthesis ( or $. The error occured while parsing the regular expression fragment: '[0-9]*?);$>>>HERE>>>'. 5) Even boost::regex("^SIGNAL W07: STD_LOGIC_VECTOR\( 255 DOWNTO 0$;$"); fails to match SIGNAL W07: STD_LOGIC_VECTOR( 255 DOWNTO 0); Points 1a and 4 suggests that boost::regex treats even escaped parantheses as special characters which is quite surprising to me. I am sure a lot of people successfully used boost::regex to match parantheses so I do wonder which part of the documentation I have missed. I'd be happy to provide more debugging information if you tell me how to produce it. Many thanks, Simon Hoerder - -- /*** * Dipl. Ing. Simon Hoerder * Work: | Private: * Department of Computer Science | First Floor Flat * Merchant Venturers Building, 2.01 | 7 Whatley Road * Woodland Road | * Bristol, BS8 1UB | Bristol, BS8 2PS * United Kingdom | United Kingdom * * http://www.cs.bris.ac.uk/Research/CryptographySecurity/ * UK mobile: +44 7564 035925 * DE mobile: +49 179 7906117 * Skype: aloisius_hingerl ***/ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iFYEARELAAYFAk5SilEACgkQE8ykjYCSVs7wGQDgmE795i+lC/qNHlwYVQvlxZtm SyiB7JreAuxQogDfUY0VLkfvNOcj9q41/43U5D8WxwljzL71+TkW2g== =wN0G -----END PGP SIGNATURE-----

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[iterator] [iterator_facade] Why is advance not defined for bidirectional iterators?
by Ovanes Markarian 22 Aug '11

22 Aug '11

Hello *! I defined a custom bidi-iterator and assumed it was going to support std::advance(iterator, Difference n), where n can be negative for random access and bidirectional iterators. The definition of my iterator's facade base looks like: struct my_iter : boost::iterator_facade < my_iter , const byte , boost::bidirectional_traversal_tag , const byte > { // some impl stuff follows... }; My tests show that calling: advance(instance_of_my_iter, N) works fine (increment implementation is called) advance(instance_of_my_iter, -N) does not work, because increment (instead of decrement) is called as well While reading through the docs for iterator facade at http://www.boost.org/doc/libs/1_46_0/libs/iterator/doc/iterator_facade.html I found the section iterator_facade Core Operations. For the advance implementation is stated there that it is only gets called for Random Access Iterators. C++ Standard clearly defines that N-Parameter to std::advance can be negative to random access and bidi iterators. Implementing void advance member in my_iter still results in the call to increment member. Can someone give me any suggestions or is it a bug in the iterator lib? My compiler is gcc 4.3 under Debian Linux with Kernal 2.6.26. and Boost 1.42. With Kind Regards, Ovanes

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[Bind] Unresolved overloaded function type
by Robert Jones 22 Aug '11

22 Aug '11

Hi All Can anyone tell me how to fix this? It's fine with one Fedora/Boost version combination, but not with another! #include <algorithm> #include <boost/bind.hpp> enum X { }; int main( ) { boost::bind<const X &>( std::max<X>, _1, _2 ); } > g++ -c a.cpp a.cpp: In function 'int main()': a.cpp:8: error: no matching function for call to 'bind(<unresolved overloaded function type>, boost::arg<1>&, boost::arg<2>&)' Thx - Rob.

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[NEWBIE] [BGL] Compile error while using greedy graph coloring example v1.47.0
by Ragavendran Gopalakrishnan 22 Aug '11

22 Aug '11

Hello all, I'm a newbie to using Boost Graph Libraries for my project. I was reading the documentation, and tried implementing the greedy graph coloring algorithm that is presented in the following webpage: http://www.boost.org/doc/libs/1_47_0/libs/graph/doc/constructing_algorithms… I get compile errors involving the following lines of code: function_requires< IntegerConcept<ColorType> >(); function_requires< size_type, ReadablePropertyMapConcept<Order> >(); typedef typename same_type<OrderType, vertex_descriptor>::type req_same; I understand that the first two function_requires calls are concept checks, and I don't know what the use of the third line is, as req_same is never used. Anyway, if I comment these three lines, my program compiles fine, and works perfectly. I am unable to understand the errors and correct them. Here is my source code (coloring.cc) - the only change I made from the example algorithm is to pass color by reference, so that I can directly access the resulting coloring. 001. #include <iostream> 002. #include <map> 003. #include <limits> 004. #include <boost/concept_check.hpp> 005. #include <boost/graph/graph_traits.hpp> 006. #include <boost/graph/graph_concepts.hpp> 007. #include <boost/graph/adjacency_matrix.hpp> 008. #include <boost/property_map/property_map.hpp> 009. 010. using namespace boost; 011. 012. // Example coloring function provided in BGL online documentation at 013. // http://www.boost.org/doc/libs/1_47_0/libs/graph/doc/constructing_algorithms… 014. template <class VertexListGraph, class Order, class Color> 015. typename graph_traits<VertexListGraph>::vertices_size_type 016. sequential_vertex_color_ting (const VertexListGraph& G, 017. Order order, const Color& color) { 018. typedef graph_traits<VertexListGraph> GraphTraits; 019. typedef typename GraphTraits::vertex_descriptor vertex_descriptor; 020. typedef typename GraphTraits::vertices_size_type size_type; 021. typedef typename property_traits<Color>::value_type ColorType; 022. typedef typename property_traits<Order>::value_type OrderType; 023. 024. function_requires< VertexListGraphConcept<VertexListGraph> >(); 025. function_requires< ReadWritePropertyMapConcept<Color, vertex_descriptor> >(); 026. function_requires< IntegerConcept<ColorType> >(); 027. function_requires< size_type, ReadablePropertyMapConcept<Order> >(); 028. typedef typename same_type<OrderType, vertex_descriptor>::type req_same; 029. 030. size_type max_color = 0; 031. const size_type V = num_vertices(G); 032. std::vector<size_type> mark(V, std::numeric_limits<size_type>::max()); 033. 034. typename GraphTraits::vertex_iterator v, vend; 035. for (tie(v, vend) = vertices(G); v != vend ; v++) { 036. (*color)[*v] = V-1; // which means "not colored" 037. } 038. 039. for (size_type i = 0 ; i < V ; i++) { 040. vertex_descriptor current = order[i]; 041. 042. // mark all the colors of the adjacent vertices 043. typename GraphTraits::adjacency_iterator ai, aend; 044. for (tie(ai, aend) = adjacent_vertices(current, G) ; ai != aend ; ++ai) { 045. mark[(*color)[*ai]] = i; 046. } 047. 048. // find the smallest color unused by the adjacent vertices 049. size_type smallest_color = 0; 050. while (smallest_color < max_color && mark[smallest_color] == i) { 051. ++smallest_color; 052. } 053. 054. // if all the colors are used up, increase the number of colors 055. if (smallest_color == max_color) { 056. ++max_color; 057. } 058. 059. (*color)[current] = smallest_color; 060. } 061. return max_color; 062. } 063. 064. int main(int, char*[]) { 065. // Create adjacency matrix for a star graph on 5 vertices 066. int numberOfVertices = 5; 067. int adjacencyMatrix[numberOfVertices][numberOfVertices]; 068. for (int i = 0 ; i < numberOfVertices ; i++) { 069. for (int j = 0 ; j < numberOfVertices ; j++) { 070. if ((i == 0)||(j == 0)&&(i != j)) { 071. adjacencyMatrix[i][j] = 1; 072. } else { 073. adjacencyMatrix[i][j] = 0; 074. } 075. } 076. } 077. 078. // Construct boost graph 079. typedef adjacency_matrix<undirectedS> UGraph; 080. typedef graph_traits<UGraph> GraphTraits; 081. typedef GraphTraits::vertex_descriptor vertex_descriptor; 082. typedef GraphTraits::vertex_iterator vertex_iterator; 083. UGraph ug(numberOfVertices); 084. for (int i = 0 ; i < numberOfVertices ; i++) { 085. for (int j = i+1 ; j < numberOfVertices ; j++) { 086. if (adjacencyMatrix[i][j] == 1) { 087. add_edge(i,j,ug); 088. } 089. } 090. } 091. 092. // Create order as an externally stored property 093. vertex_descriptor order[numberOfVertices]; 094. std::pair<vertex_iterator, vertex_iterator> p = vertices(ug); 095. for (int i = 0 ; i < numberOfVertices ; i++) { 096. order[i] = *(p.first + i); 097. } 098. 099. // Create color as an externally stored property 100. std::map<vertex_descriptor, int> color; 101. for (int i = 0 ; i < numberOfVertices ; i++) { 102. color.insert(std::make_pair(vertex_descriptor(*(p.first+i)),int(0))); 103. } 104. 105. // Get the coloring 106. sequential_vertex_color_ting(ug,order,&color); 107. 108. // Display the coloring 109. for (int i = 0 ; i < numberOfVertices ; i++) { 110. std::cout << "Color of vertex " << i << " is " << color[*(p.first+i)] << std::endl; 111. } 112. 113. return 0; 114. } The command I used to compile is (g++ version 4.4.3): $ g++ -I ../../Desktop/boost_1_47_0/ coloring.cc The compiler output is: coloring.cc: In function ‘typename boost::graph_traits<G>::vertices_size_type sequential_vertex_color_ting(const VertexListGraph&, Order, const Color&)’: coloring.cc:27: error: wrong number of template arguments (1, should be 2) ../../Desktop/boost_1_47_0/boost/property_map/property_map.hpp:191: error: provided for ‘template<class PMap, class Key> struct boost::ReadablePropertyMapConcept’ coloring.cc:28: error: expected nested-name-specifier before ‘same_type’ coloring.cc:28: error: expected initializer before ‘<’ token In file included from coloring.cc:4: ../../Desktop/boost_1_47_0/boost/concept_check.hpp: In destructor ‘boost::Integer<T>::~Integer() [with T = std::map<long unsigned int, int, std::less<long unsigned int>, std::allocator<std::pair<const long unsigned int, int> > >]’: ../../Desktop/boost_1_47_0/boost/concept_check.hpp:65: instantiated from ‘static void boost::concepts::requirement<boost::concepts::failed************ Model::************>::failed() [with Model = boost::IntegerConcept<std::map<long unsigned int, int, std::less<long unsigned int>, std::allocator<std::pair<const long unsigned int, int> > > >]’ ../../Desktop/boost_1_47_0/boost/concept_check.hpp:45: instantiated from ‘void boost::function_requires(Model*) [with Model = boost::IntegerConcept<std::map<long unsigned int, int, std::less<long unsigned int>, std::allocator<std::pair<const long unsigned int, int> > > >]’ coloring.cc:26: instantiated from ‘typename boost::graph_traits<G>::vertices_size_type sequential_vertex_color_ting(const VertexListGraph&, Order, const Color&) [with VertexListGraph = main(int, char**)::UGraph, Order = main::vertex_descriptor*, Color = std::map<long unsigned int, int, std::less<long unsigned int>, std::allocator<std::pair<const long unsigned int, int> > >*]’ coloring.cc:106: instantiated from here ../../Desktop/boost_1_47_0/boost/concept_check.hpp:69: error: ‘class std::map<long unsigned int, int, std::less<long unsigned int>, std::allocator<std::pair<const long unsigned int, int> > >’ has no member named ‘error_type_must_be_an_integer_type’ When I comment lines 26-28, the program compiles successfully and executing a.out gives the following output, as expected: Color of vertex 0 is 0 Color of vertex 1 is 1 Color of vertex 2 is 1 Color of vertex 3 is 1 Color of vertex 4 is 1 Please advise me on what the compiler errors mean. I did try digging into some of the header files, but I couldn't find out what the mistake is. Regards, Raga.

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[Boost.Build] Problem with the Boost library support module
by Marcel 21 Aug '11

21 Aug '11

Hi, I have compiled Boost.Buildv2 from the Boost V1.47 sources and have successfully compiled the Boost libraries with it. Now I want to use BBv2 in my own project, which uses the Boost libraries. So I tried using the Boost library support module: I added to my user-config.jam: using boost : 1.47 : <include>C:/boost_1_47_0/boost <library>C:/boost_1_47_0/stage/lib ; and to my project's jamroot file: import boost ; boost.use-project 1.47 ; I installed BBv2 to C:/boost_1_47_0/bjam and added this to the PATH. Calling bjam gives me the following error message, because it can't find the support module (I assume): boost.jam: No such file or directory C:/boost_1_47_0/bjam/share/boost-build/build\toolset.jam:38: in toolset.using rule boost.init unknown in module toolset. C:/boost_1_47_0/bjam/share/boost-build/build\project.jam:888: in using C:\Users\zaphod\user-config.jam:3: in modules.load C:/boost_1_47_0/tools/build/v2\build-system.jam:257: in load-config C:/boost_1_47_0/tools/build/v2\build-system.jam:399: in load-configuration-files C:/boost_1_47_0/tools/build/v2\build-system.jam:555: in load C:\boost_1_47_0\bjam\share\boost-build\kernel\modules.jam:283: in import C:\boost_1_47_0\bjam\share\boost-build\kernel\bootstrap.jam:142: in boost-build C:\boost_1_47_0\bjam\share\boost-build\boost-build.jam:8: in module scope I located boost.jam in the source tree of bbv2 of the boost libraries in the directory contrib. This is on Windows 7 x64 with mingw(32) as compiler. What is wrong here? Can I help bjam finding the boost.jam file? Many thanks in advance, Marcel

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Serialization: how to port binary archives containing NAN created with version 1.43 to version 1.47?
by Robert Lupton the Good 21 Aug '11

21 Aug '11

>> Because of a user request we support serialization of nan and inf. >> The official boost archives don't, as you already found out. > Robert Ramey wrote: > I just looked at the page. It looks very interesting to me. When > I have some time, I will be investigating which of these might > be included in the boost distribution of the serialization library. Does this mean that you plan to support IEEE special values (e.g. NaN, Inf) in boost, or some other part of Christian's work? There's traffic on the IEEE limitation (feature?) in boost::serialize dating back to at least 2005 --- some with your name on it! R

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[iostreams] encryption filters
by Sean Farrow 21 Aug '11

21 Aug '11

Hi: Has anybody written encryption filters for the IOStreams library using crypto++? I need to do this but didn't want to duplicate effort if any existed already. Cheers Sean.

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[Serialization] Prevent member serialization in a non intrusive situation
by Sean Farrow 21 Aug '11

21 Aug '11

Hi: I am using boost.serialization, and need to prevent members (boost.thread, and Booleans) being serialized. Given that I am using non-intrusive serializing code, what is the best way of doing this. Any help appreciated. Cheers Sean.

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