August 2003 - Boost-users - lists.boost.org

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 06 Aug '03

06 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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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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