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Problems with if_then_else_return in boost::lambda library
by Ioffe, Robert 07 Aug '03

07 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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[function] How to extract a tuple<A0,A1> of arguments from a boost::function<>?
by Fernando Cacciola 07 Aug '03

07 Aug '03

Short question: As the Subject says, given a boost::function{1..N}<>, how can I extract a tuple of all its arguments? Long question: Anyway, what I'm really trying to do is this: Given some classes with different methods: struct X { void f(int n ) ; } ; struct Y { void g(char c, double d ) ; } ; I want to easly create _polymorphic_ closures binding member functions of X /Y with instances of X/Y and function arguments. The goal is the have a deferred 'action' list for easy backtracing of an algorithm. That is, instead of directly calling: X x ; Y y ; x.f(1); y.g('a',1.2); I want to do something that would look like: X x; Y y; ActionList actions; actions.push_back( make_closure(&X::f, x,1) ); actions.push_back( make_closure(&Y::g, y,'a',1.2) ); std::for_each(actions.begin(),actions.end(),execute_action()); TIA Fernando Cacciola

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filesystem compilation on tru64 unix
by allysonlurena 07 Aug '03

07 Aug '03

Hi all, I have been trying to build the filesystem library for one of our alpha servers running tru64 unix. I have managed to compile bjam using the tru64cxx toolset. Then, I went into the filesystem build directory and ran the following, but it has been hanging for over 30 minutes now on the last command you see below. Can anyone help? It could just be our machines, but I am at a loss. Does anyone have any ideas? Any help would be appreciated! Thanks Allyson $ cxx -V Compaq C++ V6.5-014 for Compaq Tru64 UNIX V5.1A (Rev. 1885) Compiler Driver V6.5-014 (cxx) cxx Driver rum:/.../boost_1_30_0/libs/filesystem/build $ bjam "-sTOOLS=tru64cxx65" ...found 432 targets... ...using 1 temp target... ...updating 9 targets... tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/exception.o tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/operations_posix_windows.o cxx: Warning: ../src/operations_posix_windows.cpp, line 236: #767-D conversion from pointer to smaller integer assert( m_imp.get() ); // fails if dereference end iterator ------^ cxx: Warning: ../src/operations_posix_windows.cpp, line 242: #767-D conversion from pointer to smaller integer assert( m_imp.get() ); // fails on increment end iterator ------^ tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/path_posix_windows.o tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/convenience.o tru64cxx65-Archive-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/libboost_filesystem.a ar: Warning: creating ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/libboost_filesystem.a Ranlib ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/libboost_filesystem.a ...using <libs!filesystem!build/libboost_filesystem.a/tru64cxx65/release>exception.o... tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/release/operations_posix_windows.o So, it seems to hang at the last command above. Thanks again! Allyson

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cvs checkout probs
by Angus Leeming 07 Aug '03

07 Aug '03

Hi, I have just tried to checkout the boost cvs tree from sourceforge, but get stuck at cvs server: Updating boost/libs/numeric/mtl/test cvs server: [05:07:19] waiting for anoncvs_boost's lock in /cvsroot/boost/boost/libs/numeric/mtl/test I can subsequently check out the remaining stuff with $ cat tmp pool preprocessor property_map python random rational regex signals smart_ptr spirit static_assert test thread timer tokenizer tuple type_traits utility $ for dir in `cat tmp`; do cvs -z3 co boost/libs/$dir; done so it appears that the problem is specific to the boost/libs/numeric/mtl/test directory. Kind regards, Angus

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[boost] filesystem lib & linking (MSVC.NET)
by Jonathan Roewen 07 Aug '03

07 Aug '03

Hi All, I'm trying to use the filesystem lib, but I'm having some problems figuring out how to build it properly. I'm using MSVC.NET on WindowsXP, and I ran the bjam tool like in the docs for the whole set of libraries. It took me a while to figure out where it had put everything, and finally found a file called libboost_filesystem.lib. I copied it to a convenient location, added the library path and lib file to my project settings, and then tried to link my app. MSVC then gave a bunch of linker errors, and suggested to add MSVCRT to the nodefaultlib setting, so I did that, and got less linker errors. All that is left is some thing to do with exception & string classes. Linker errors are all about multiply defined symbols. I suppose I'm doing something wrong somewhere along the line, but not sure what. I can't tell if bjam is actually doing what it's supposed to, and the documentation around the place can be pretty sparse in places, so I hope someone can point out what I can do to get things working. Regards, Jonathan Roewen

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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

1 0

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.

2 2

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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boost::tokenizer
by peter 05 Aug '03

05 Aug '03

hi there im trying to tokenize a string where any sort of blank space (' ', or '\t') is a delimiter, and allow having spaces in a token by enclosing it with a single quote (') character... the code below does not work well if i have more than one space characters (' ' or '\t') beside eachother... it simply keeps the token (even though the result is an empty string)... #include <string> #include <vector> #include <boost/tokenizer.hpp> std::vector<std::string> tokenizeStr(const std::string &str) { std::vector<std::string> result; boost::escaped_list_separator<char> sep("", " \t", "'"); boost::tokenizer<boost::escaped_list_separator<char> > tok(str, sep); for(boost::tokenizer<boost::escaped_list_separator<char> >::iterator p=tok.begin(); p!=tok.end(); p++) { result.push_back(static_cast<std::string>(*p)); } return result; } does anyone have any ideas how to make this work without actually going through the list manually and deleting the empty tokens?? by the way, im using boost 1.29 thanks peter

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New Bee Question
by sarwanaggarwal 03 Aug '03

03 Aug '03

Hi: 1. I finally built "lib" for file-system. 2. I copied borland's debug version to a project directory. 3. I am getting a link error from [Linker Fatal Error] Fatal: Expected a file name: Borlannd C++ Builder Version 6.0. 4. I get numerous errors from MSVC++. With little help, I am sure to get started soon. Thanks. Sarwan

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schizophrenic code.
by chris_baus 01 Aug '03

01 Aug '03

Am I only one that is uncomfortable with the following: std::vector<boost::any> mySchizophrenicCollection; Just curious.

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schizophrenic code.
by chris_baus 01 Aug '03

01 Aug '03

The following seems like a battle of wills between two different typing paradigms. std::vector<boost::any> m_schizophrenicCollection; The thought of this is making me a bit uneasy. comments? ~christopher

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Re: [Spirit-general] Problem with Parsing
by Joel de Guzman 01 Aug '03

01 Aug '03

Hi, Have you tried using the Spirit debugger? Cheers, -- Joel de Guzman joel at boost-consulting.com http://www.boost-consulting.com http://spirit.sf.net Surinder Pal Singh <sps22(a)yahoo.com> wrote: > Hi, > I am trying to use Spirit (in the latest Boost 1_30_0) > for a project. I want to parse a file whose structure > is the following: > > section1 { > something; > } > > I am using the file_iterator to iterate on the input > file and then define comment as well as the grammar. I > am at my wits end why my parser keeps failing. (When > this simple grammar works, I want to make the parser > more complex.) My code is attached below. (Note: I > used the example in the distribution c_grammar.cpp as > the starting point for it.) > > Thanks. > > -surinder > I have attempted to join the spirit mail list, but > have not received the confirmation so far, but please > feel free to respond to me at: sps22_at_yahoo_dot_com > > > PS: This input file structure is going to be, of > course, more complicated than the example shown above. > Inside the setions, I would like to pass on flags and > statements to the code. If it is better for me to use > another approach to parse this file structure, please > suggest me. > [snip]

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A Quick Question about Threads
by Paul Grenyer 01 Aug '03

01 Aug '03

Hi All I'm planning on replacing all our (Win32 API Wrapped) threads with the boost threads. I was looking at the thread class interface and there isn't a method to ask if the thread is still running. This is something we use quite a lot in out current wrapper. To get around this I was thinking of using a member variable in the function object that is passed to the thread constructor to indicated whether the thread had finished. Is there a better way? I've not had a really good look at the docs yet, but there doesn't appear to be a Critical Section class. Should I be using the Mutex for synchronisation instead? -- Regards Paul Paul Grenyer Email: pjgrenyer(a)iee.org Web: www.paulgrenyer.co.uk EvaneScence: http://www.evanescence.com

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Graph Library: Ordered Vertex List?
by dmatt001 01 Aug '03

01 Aug '03

Hi Guys, I would like to use an ordered vertex list (ie based on property type) in an implementation that I am working on such that duplication can be avoided. I have read and understand how to implement an ordered edge list thanks to the previous posts but am finding it hard to get started! Perhaps I have missed the key example? It appears that from the way config::VertList is constructed that it may be a similar process in nature? adj_list_impl::add_vertex appears to discard the boolean return value from the associative insertion. Would such a construction allow me to avoid the duplication I seek to avoid? I am guessing so, but some advice would give me a confidence "boost". ( <-- It's a lame pun: I really do need help ;-) ) My first steps are below rehashing the excellent ordered edges example with a simple search/replace and maching my target container base. I'll keep plugging along with it anyway and it may just compile one day. Suggestions/Ideas/Refs/Ptrs are appreciated. Matt --- first guess follows --- template <class VertDesc> struct order_by_name : public std::binary_function<VertDesc,VertDesc,bool> { bool operator()(const VertDesc& v1, const VertDesc& v2) const { // Order by vertex name. return boost::get(boost::vertex_name, v1) < boost::get(boost::vertex_name, v2); } }; #if !defined BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION struct ordered_set_by_nameS { }; namespace boost { template <class ValueType> struct container_gen<ordered_set_by_nameS, ValueType> { typedef std::set<ValueType, order_by_name<ValueType> > type; }; } #else struct ordered_set_by_nameS { template <class T> struct bind_ { typedef std::multiset<T, order_by_name<T> > type; }; }; namespace boost { template <> struct container_selector<ordered_set_by_nameS> { typedef ordered_set_by_nameS type; }; } #endif

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Compile time Problem with boost::type_traits library
by Amit Bhatia 01 Aug '03

01 Aug '03

Hello, I am trying to use the boost::function library which in turn includes many of the headers from other boost libraries. I am using g++ 3.2 with: g++ -c -g -fwritable-strings -Wno-deprecated -static -ansi -pedantic -DANSI_HEADERS -D_G_HAVE_BOOL as the options. The file is_integral.hpp and the file is_convertible.hpp in the type_traits library contain the declarations of the type long long which the ISO C++ seemingly doesn't accept. The compiler gives the warning: ISO C++ does not support `long long' . I don't think there is a new version of this on boost. I downloaded the boost lib sometime in June Version 1.30.0. Can this problem be because of any of the compiler options that I am using? thanking you, regards, amit.

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Spirit Sequential-or
by Bruno Martínez 01 Aug '03

01 Aug '03

Hi boosters, In operators.html (a || b) is said to be equivalent to (a | b | a >> b), but, if I understand precedence correctly, it should be equivalent to (a >> b | a | b). I'm just learning Spirit, so this may probably be my mistake, right? Cheers, Bruno Martinez ---------------------------------------------------- ATENCION Su servicio de correo tiene antivirus ?? @internet URUGUAY: http://www.internet.com.uy

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FC++ in Boost, Spirit, Preprocessing
by Jan Kybic 31 Jul '03

31 Jul '03

Hello, I want to write in favor of Boostifying the functional library FC++, which I find very useful. Would a merger with the Phoenix library from Spirit (already in Boost) be feasible? Phoenix seems to have a slightly nicer syntax but lacks (as far as I know) the Haskell prelude functions and lazy list implementation, also the closures do not seem very intuitive to me. My main concern with both FC++ and Phoenix is that when defining new functiods, the user needs to write a lot of often repetitive code. This could be simplified using a suitable preprocessor. Would that be acceptable and are there other people interested ? Yours, Jan -- ------------------------------------------------------------------------- Jan Kybic <kybic(a)ieee.org> tel. +420 2 2435 7264 or <kybic(a)fel.cvut.cz>, http://cmp.felk.cvut.cz/~kybic

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