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Re: what is wrong with boost::bind?
by Jason Shirk 06 Aug '03

06 Aug '03

"yxh" <yg-boost-users(a)m.gmane.org> wrote in message news:<bgqfkv$eeu$1(a)main.gmane.org>... > I solved it by using Visual Assistant .NET I can't seem to reproduce the problem you have reported. If you could send me (jasonsh(a)microsoft.com) a project that reproduces the problem, I'd appreciate it. You might consider trying Intellisense a bit more. Because we use a variant of our C++ compiler for Intellisense, it has capabilities that are beyond many other editors. It's far from perfect, as you've found, but as far as we are aware, the template support for auto completion is much better than with any other similar tool. -- Jason Shirk VC++ Compiler Team

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Problems with if_then_else_return in boost::lambda library
by Ioffe, Robert 06 Aug '03

06 Aug '03

Hi, If I have a vector of strings vector<string> v; v.push_back("One"); v.push_back("Two"); v.push_back("Three"); v.push_back("Four"); v.push_back("Five"); and define arithmetic action plus like this: namespace boost { namespace lambda { struct plain_return_type_2<arithmetic_action<plus_action>, std::string, std::string> { typedef std::string type; }; } } then the following code works just fine: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + string(", ") + _2) << endl; and the following also works wonderfully: int i = 1; cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + bind(constructor<string>(), var(i)++, ' ') + _2) << endl; Now, if I want to use if_then_else_return as shown below, it fails miserably, producing a huge error message: cout << accumulate(v.begin(), v.end(), string(), if_then_else_return(_1 == string(), _1, _1 + bind(constructor<string>(), var(i)++, ' ') + _2)) << endl; Now for the questions: What is the proper way to use if_then_else_return? Why do I need to define a separate arithmetic action for strings, even though they are a common library type? Is there a way to say the most intuitive: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + ", " + _2) << endl; Is there way to do more intuitive: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + string(i++, ' ') + _2) << endl; Thank you for your help. Robert Ioffe [Non-text portions of this message have been removed]

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prim_minimum_spanning_tree crashes
by Stephan Höfer 06 Aug '03

06 Aug '03

Hello, I try to use prim_minimum_spanning_tree to find rings in subgraphs doing the following: typedef subgraph< adjacency_list<vecS, vecS, undirectedS, VertexProperty, EdgeProperty> > Graph; /... building Graph g with some vertices and edges for(int i=0; i<7; ++i) { add_vertex(g); LAMath::Vec3_f tVec((float)i, (float)(6-i), .0); put(vertex_point_t(), g, i, tVec); } property_map<Graph, edge_weight_t>::type weightmap = get(edge_weight, g); Edge e; bool inserted; tie(e, inserted) = add_edge(0, 1, g); weightmap[e] = 1; tie(e, inserted) = add_edge(1, 2, g); weightmap[e] = 1; tie(e, inserted) = add_edge(2, 3, g); .../ Graph tSubGraph = g.create_subgraph(); add_vertex(1, tSubGraph); add_vertex(3, tSubGraph); add_vertex(4, tSubGraph); add_vertex(6, tSubGraph); std::vector < graph_traits < Graph >::vertex_descriptor > p(num_vertices(tSubGraph)); prim_minimum_spanning_tree(tSubGraph, &p[0]); After having created the graph g, I call the create_subgraph member function to get an induced subgraph of it. Trying to use the prim_minimum_spanning_tree function it crashes in dijkstra_dispatch1 by trying to delete the local variable std::vector<D> distance_map(n). Is there something missing in my code which leads to that crash? It works for the root graph but not for any new created subgraph. Help would be appreciated. Thanks in advance Stephan

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boost and vxWorks?
by Alexander Nasonov 06 Aug '03

06 Aug '03

Does anybody use boost libraries under Vxworks? I'm especially interested in pool and threads libraries. Thankin advance -- Alexander Nasonov Remove minus and all between minus and at from my e-mail for timely response

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How to avoid warning C4275 in MSVC 7.1
by yxh 06 Aug '03

06 Aug '03

Hello, when I build /libs/thread/examples/thread.cpp, I got warning C4275. I think it is because std::logic_error is not defined as dllexport/dllimport. Can anyone tell me how to correct this? TIA.

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A good class to substitute boost.tuple
by Black Ice 06 Aug '03

06 Aug '03

Pls. look the source codde and demo code, you will find a good substitute for boost.tuple. Any suggestions are appreciated. Source code #ifndef _PROPERTYLIST_HEADER_ #define _PROPERTYLIST_HEADER_ namespace pl{ struct NullType { NullType() {} template<typename T> NullType(const T&) {} }; template<typename H, typename T> struct PropertyList { typedef H head_type; typedef T tail_type; typedef PropertyList<head_type, tail_type> my_type; PropertyList() : head_value(head_type()), tail_value(tail_type()) {} template<typename OtherHead, typename OtherTail> PropertyList(const OtherHead & head, const OtherTail & tail) : head_value(head), tail_value(tail) {} PropertyList(const my_type & other) : head_value(other.head_value), tail_value(other.tail_value) {} void swap(my_type & other) { std::swap(head_value, other.head_value); std::swap(tail_value, other.tail_value); } my_type & operator=(const my_type & other) { if(this != &other) { my_type temp(other); swap(temp); } return *this; } head_type head_value; tail_type tail_value; }; #define PROPERTYLIST_1(T1) PropertyList<T1, NullType> template<typename T1> PROPERTYLIST_1(T1) make_list(const T1 & t1) { return PROPERTYLIST_1(T1)(t1, NullType()); } #define PROPERTYLIST_2(T1, T2) PropertyList<T1, PROPERTYLIST_1(T2) > template<typename T1, typename T2> PROPERTYLIST_2(T1, T2) make_list(const T1 & t1, const T2 & t2) { return PROPERTYLIST_2(T1, T2)(t1, make_list(t2)); } #define PROPERTYLIST_3(T1, T2, T3) PropertyList<T1, PROPERTYLIST_2(T2, T3) > template<typename T1, typename T2, typename T3> PROPERTYLIST_3(T1, T2, T3) make_list(const T1 & t1, const T2 & t2, const T3 & t3) { return PROPERTYLIST_3(T1, T2, T3)(t1, make_list(t2, t3)); } #define PROPERTYLIST_4(T1, T2, T3, T4) PropertyList<T1, PROPERTYLIST_3(T2, T3, T4) > template<typename T1, typename T2, typename T3, typename T4> PROPERTYLIST_4(T1, T2, T3, T4) make_list(const T1 & t1, const T2 & t2, const T3 & t3, const T4 & t4) { return PROPERTYLIST_4(T1, T2, T3, T4)(t1, make_list(t2, t3, t4)); } #define PROPERTYLIST_5(T1, T2, T3, T4, T5) PropertyList<T1, PROPERTYLIST_4(T2, T3, T4, T5) > template<typename T1, typename T2, typename T3, typename T4, typename T5> PROPERTYLIST_5(T1, T2, T3, T4, T5) make_list(const T1 & t1, const T2 & t2, const T3 & t3, const T4 & t4, const T5 & t5) { return PROPERTYLIST_5(T1, T2, T3, T4, T5)(t1, make_list(t2, t3, t4, t5)); } #define PROPERTYLIST_6(T1, T2, T3, T4, T5, T6) PropertyList<T1, PROPERTYLIST_5(T2, T3, T4, T5, T6) > template<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6> PROPERTYLIST_6(T1, T2, T3, T4, T5, T6) make_list(const T1 & t1, const T2 & t2, const T3 & t3, const T4 & t4, const T5 & t5, const T6 & t6) { return PROPERTYLIST_6(T1, T2, T3, T4, T5, T6)(t1, make_list(t2, t3, t4, t5, t6)); } #define PROPERTYLIST_7(T1, T2, T3, T4, T5, T6, T7) PropertyList<T1, PROPERTYLIST_6(T2, T3, T4, T5, T6, T7) > template<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7> PROPERTYLIST_7(T1, T2, T3, T4, T5, T6, T7) make_list(const T1 & t1, const T2 & t2, const T3 & t3, const T4 & t4, const T5 & t5, const T6 & t6, const T7 & t7) { return PROPERTYLIST_7(T1, T2, T3, T4, T5, T6, T7)(t1, make_list(t2, t3, t4, t5, t6, t7)); } #define PROPERTYLIST_8(T1, T2, T3, T4, T5, T6, T7, T8) PropertyList<T1, PROPERTYLIST_7(T2, T3, T4, T5, T6, T7, T8) > template<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7, typename T8> PROPERTYLIST_8(T1, T2, T3, T4, T5, T6, T7, T8) make_list(const T1 & t1, const T2 & t2, const T3 & t3, const T4 & t4, const T5 & t5, const T6 & t6, const T7 & t7, const T8 & t8) { return PROPERTYLIST_8(T1, T2, T3, T4, T5, T6, T7, T8)(t1, make_list(t2, t3, t4, t5, t6, t7, t8)); } #define PROPERTYLIST_9(T1, T2, T3, T4, T5, T6, T7, T8, T9) PropertyList<T1, PROPERTYLIST_8(T2, T3, T4, T5, T6, T7, T8, T9) > template<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7, typename T8, typename T9> PROPERTYLIST_9(T1, T2, T3, T4, T5, T6, T7, T8, T9) make_list(const T1 & t1, const T2 & t2, const T3 & t3, const T4 & t4, const T5 & t5, const T6 & t6, const T7 & t7, const T8 & t8, const T9 & t9) { return PROPERTYLIST_9(T1, T2, T3, T4, T5, T6, T7, T8, T9)(t1, make_list(t2, t3, t4, t5, t6, t7, t8, t9)); } #define PROPERTYLIST_10(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10) PropertyList<T1, PROPERTYLIST_9(T2, T3, T4, T5, T6, T7, T8, T9, T10) > template<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7, typename T8, typename T9, typename T10> PROPERTYLIST_10(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10) make_list(const T1 & t1, const T2 & t2, const T3 & t3, const T4 & t4, const T5 & t5, const T6 & t6, const T7 & t7, const T8 & t8, const T9 & t9, const T10 & t10) { return PROPERTYLIST_10(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10)(t1, make_list(t2, t3, t4, t5, t6, t7, t8, t9, t10)); } template <class PList> struct Length { enum{value = 1 + Length<PList::tail_type>::value}; }; template <> struct Length<NullType> { enum{value = 0}; }; template<class PList, unsigned int N> struct TypeAt { typedef typename TypeAt<typename PList::tail_type, N-1>::type type; }; template<class PList> struct TypeAt<PList, 0> { typedef typename PList::head_type type; }; template<int N> struct TypeAt<NullType, N> { }; template<> struct TypeAt<NullType, 0> { typedef NullType type; }; template<class PList, class T> struct Append { typedef PropertyList<typename PList::head_type, typename Append< typename PList::tail_type, T>::type> type; }; template<class T> struct Append<NullType, T> { typedef PropertyList<T, NullType> type; }; template<class PList, class T> struct Push { typedef PropertyList<T, PList> type; }; template<class PList> struct Pop { typedef typename PList::tail_type type; }; template<class PList, unsigned int N> struct RemoveAt { typedef PropertyList<typename PList::head_type, typename RemoveAt<typename PList::tail_type, N-1>::type> type; }; template<class PList> struct RemoveAt<PList, 0> { typedef typename PList::tail_type type; }; template<int N> struct RemoveAt<NullType, N> { }; template<> struct RemoveAt<NullType, 0> { }; template<class PList, class T, unsigned int N> struct InsertAt { typedef PropertyList<typename PList::head_type, typename InsertAt<typename PList::tail_type, T, N-1>::type> type; }; template<class PList, class T> struct InsertAt<PList, T, 0> { typedef PropertyList<T, PList> type; }; template<class T, unsigned int N> struct InsertAt<NullType, T, N> { }; template<class T> struct InsertAt<NullType, T, 0> { }; template<class PList, unsigned int N> struct ValueAt { static typename TypeAt<PList, N>::type & get(PList & plist) { typedef typename PList::tail_type tail_type; tail_type & tail = plist.tail_value; return ValueAt<tail_type, N-1>::get(tail); } static const typename TypeAt<PList, N>::type & get(const PList & plist) { typedef const typename PList::tail_type tail_type; tail_type & tail = plist.tail_value; return ValueAt<tail_type, N-1>::get(tail); } }; template<class PList> struct ValueAt<PList, 0> { static typename TypeAt<PList, 0>::type & get(PList & plist) { return plist.head_value; } static const typename TypeAt<PList, 0>::type & get(const PList & plist) { return plist.head_value; } }; template<class PList, template<class> class FunctionClass, typename T = NullType> struct Visitor { static void for_each(PList & plist, T & t) { FunctionClass<typename PList::head_type> f(t); f(plist.head_value); typedef typename PList::tail_type tail_type; Visitor<tail_type, FunctionClass, T>::for_each(plist.tail_value, t); } }; template<class PList, template<class> class FunctionClass> struct Visitor<PList, FunctionClass, NullType> { static void for_each(PList & plist) { FunctionClass<typename PList::head_type>()(plist.head_value); typedef typename PList::tail_type tail_type; Visitor<tail_type, FunctionClass, NullType>::for_each(plist.tail_value); } }; template<template<class> class FunctionClass, typename T> struct Visitor<NullType, FunctionClass, T> { static void for_each(NullType & plist, T &) { } }; template<template<class> class FunctionClass> struct Visitor<NullType, FunctionClass, NullType> { static void for_each(NullType & plist) { } }; } // namespace pl #endif // _PROPERTYLIST_HEADER_ demo code #include <iostream> #include <string> #include <boost/type_traits.hpp> #include <PropertyList.h> #include <utility> using namespace std; using namespace boost; using namespace pl; template<typename T> struct Dump { void operator()(const T & t) { cout << t << endl; } }; template<typename T> struct LoadFromStream { LoadFromStream(long stream) : m_stream(stream) { } void operator()(T & t) { cout << "Load <" << t << "> from stream " << m_stream << endl; } long m_stream; }; template<typename PList> void SaveToStream(long stream, const PList & plist) { cout << "Save <" << plist.head_value << "> to stream " << stream << endl; SaveToStream(stream, plist.tail_value); } template<> void SaveToStream<NullType>(long stream, const NullType &) { } void test(void) { typedef PROPERTYLIST_3(int, long , double) MY_PROPS; BOOST_STATIC_ASSERT( (Length<MY_PROPS>::value == 3) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS, 0>::type, int>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS, 1>::type, long>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS, 2>::type, double>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS, 3>::type, NullType>::value) ); typedef Append<MY_PROPS, float>::type MY_PROPS2; BOOST_STATIC_ASSERT( (Length<MY_PROPS2>::value == 4) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS2, 0>::type, int>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS2, 1>::type, long>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS2, 2>::type, double>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS2, 3>::type, float>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS2, 4>::type, NullType>::value) ); typedef Push<MY_PROPS, char>::type MY_PROPS3; BOOST_STATIC_ASSERT( (Length<MY_PROPS3>::value == 4) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS3, 0>::type, char>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS3, 1>::type, int>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS3, 2>::type, long>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS3, 3>::type, double>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS3, 4>::type, NullType>::value) ); typedef Pop<MY_PROPS>::type MY_PROPS4; BOOST_STATIC_ASSERT( (Length<MY_PROPS4>::value == 2) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS4, 0>::type, long>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS4, 1>::type, double>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS4, 2>::type, NullType>::value) ); typedef RemoveAt<MY_PROPS, 1>::type MY_PROPS5; BOOST_STATIC_ASSERT( (Length<MY_PROPS5>::value == 2) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS5, 0>::type, int>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS5, 1>::type, double>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS5, 2>::type, NullType>::value) ); typedef InsertAt<MY_PROPS, short, 1>::type MY_PROPS6; BOOST_STATIC_ASSERT( (Length<MY_PROPS6>::value == 4) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS6, 0>::type, int>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS6, 1>::type, short>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS6, 2>::type, long>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS6, 3>::type, double>::value) ); BOOST_STATIC_ASSERT( (is_same<TypeAt<MY_PROPS6, 4>::type, NullType>::value) ); typedef Append<MY_PROPS, string>::type MY_PROPS7; MY_PROPS7 props; ValueAt<MY_PROPS7, 0>::get(props) = 1; ValueAt<MY_PROPS7, 1>::get(props) = 2; ValueAt<MY_PROPS7, 2>::get(props) = 3.3; ValueAt<MY_PROPS7, 3>::get(props) = "Hello World"; Visitor<MY_PROPS7, Dump>::for_each(props); long stream = 1; Visitor<MY_PROPS7, LoadFromStream, long>::for_each(props, stream); MY_PROPS7 props2 = make_list(10, 20L, 3.1415, string("Hello World")); SaveToStream(stream, props2); } -- Regards, Black Ice Çë²»Òª»ØžŽµœÎÒµÄÓÊÏä ×ÔÓÉ£šliberty£©ÎÞ·ÇŸÍÊÇÕâÑùÒ»ÖÖ³ÐÅµ£ºÃ¿žöÈËœ«»áµÃµœÒ»ÖÖ±£ÕÏ£¬±£ÕÏÎÒÃÇ¿ÉÒÔÓë ÈšÍþ¡¢¶àÊý¡¢Á÷Ë×Œ°ÓßÂÛµÄÓ°ÏìÏà¿¹ºâ¡£ http://www.leoliu.net

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Subscripting and operator()
by Christopher Dawson 05 Aug '03

05 Aug '03

Hi there, I am wrapping a class with an operator()(int, int) which I'd like to make available in Python as a subscript operator, but haven't been able to find any documentation on this nor guess the appropriate .def Is this possible and if so can anyone help? Regards, Chris.

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Linking with BGL adjacency_list_io.hpp
by Solomon Gibbs 05 Aug '03

05 Aug '03

Hi, I'm having trouble linking code that uses adjacency_list_io.hpp. If the header is included is included in more than one compilation unit, I get "multiple definition of function" errors for the non-template functions in adjacency_list_io.hpp: std::istream& operator >> ( std::istream& in, no_property& ) and void getSubset( no_property& p, const no_property& s ) I'm sure that there is some C+ subtlety that I'm missing here, but I'm not familiar enough with the library to understand what it is. Shouldn't non-template function code be in a .cpp file to keep this sort of thing from happening? - Solomon

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degree_size_type vs integer
by Jérémie Leguay 05 Aug '03

05 Aug '03

Hi! I have a simple question: if I use the in_degree function I have in return a degree_size_type. How it is possible to convert it in integer? /Jérémie ___________________________________________________________ Do You Yahoo!? -- Une adresse @yahoo.fr gratuite et en français ! Yahoo! Mail : http://fr.mail.yahoo.com

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shared_ptr Intellisense
by destinati2001 05 Aug '03

05 Aug '03

Hello, Has anyone been able to get IntelliSense member information for the boost::shared_ptr class? I am using Visual Studio.NET 2003. I have setup the boost directory as a subfolder of my project directory. Moreover, I *am* able to obtain Intellisense information for boost::any, any_cast, get_pointer, make_permuation_iterator, permutation_iterator_generator, permutation_iterator_policies, scoped_ptr, signal, and swap. The fact that scoped_ptr works fine makes me wonder why shared_ptr doesn't work. Any help would be much appreciated! Thanks, Jeff

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