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boost::mpl:: operators ...power metafunction?
by Andy Little 26 Jan '04

26 Jan '04

Hi, I am implementing the mpl math operators for my physical_quantities type. Ideally I would like to declare a boost::mpl::power<A,B> metafunction. I would like to do: typedef Power_type<...> P ; pq_xx a; boost::mpl::power< pq_xx, P >::type b = run_time_power<P>( a); OTOH: boost::mpl::power< P, pq_xx >::type b = run_time_power<P>( a); (param order ... TBD) I am assuming it is ok to specialise plus, minus, multiplies etc in the boost::mpl namespace? I could of course put power (or whatever name) outside the boost::mpl namespace but that is not ideal. Any thoughts? regards Andy Little

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how to create fixtures in unit test framework
by eli＠ce.berkeley.edu 25 Jan '04

25 Jan '04

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bind1st and bind2nd together
by Hossein Haeri 25 Jan '04

25 Jan '04

Dear all, I've got a ternary function (which is std::find), and want to bind the first and second parameters (to the begining and the end of a std::vector). Then send the result to compose2 to check the equality for the end of the vector. Here is what I did: copy_if(istream_iterator<Terminal>(cin), istream_iterator<Terminal>(), back_inserter(temp), compose2(equal<set<Terminal>::iterator>(), bind1st(bind1st_3(ptr_fun(f), V_.begin()), V_.end()), V_.end()))); (I've prepared any goodie needed by ternary functions for the above statement: ptr_fun, bind1st_3, ...) Dev-C++ 4.9.8.0 (GCC 3.3.2 I think), gives me several errors (including "Reference to Reference" problem), and I'm nearly convinced not to continue it this way. Now, how do you, boost guys, do that? TIA, --Hossein __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free web site building tool. Try it! http://webhosting.yahoo.com/ps/sb/

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MPL Issue in apply.hpp in CVS
by Martin Ecker 25 Jan '04

25 Jan '04

Hello, I wanted to use boost::variant, so I got the Boost libraries from CVS. While developing a small test program I discovered an issue in the MPL header file apply.hpp that prevented successful compilation on MSVC 7.1. In particular, starting on line 245 in boost/mpl/apply.hpp it says // ISO98 C++, with minor concession to vc7 template< typename F, AUX_APPLY_N_PARAMS(i, typename T) > struct BOOST_PP_CAT(apply,i) { // Metafunction forwarding confuses vc7 typedef typename F::template apply< AUX_APPLY_N_PARAMS(i, T) >::type BOOST_MPL_AUX_LAMBDA_SUPPORT( BOOST_PP_INC(i) , BOOST_PP_CAT(apply,i) , (F, AUX_APPLY_N_PARAMS(i,T)) ) }; The first typedef in that struct should be // Metafunction forwarding confuses vc7 typedef typename F::template apply< AUX_APPLY_N_PARAMS(i, T) >::type type; Regards, Martin ---------------------------------------------------------------- Visit my pages on the Web: XEngine Project Page: http://xengine.sourceforge.net Private homepage: http://members.liwest.at/GroovingArts

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Interval Library?
by David Brownell 25 Jan '04

25 Jan '04

I think I am looking for functionality that is contained with the Interval library, but am having a hard time digesting the documentation for this particular library. I would like an Interval that goes from a min_value to a max_value, where each value is the previous value + N. For example, the interval {2, 6, 10, 14, 18} has a minimum value of 2, a maximum value of 18, and increments by 4. Given this interval, I would like a function, Foo, that works as follows: Interval(2, 18, 4) i; i.Foo(2) == 2 i.Foo(6) == 2 i.Foo(0) == 2 i.Foo(18) == 18 i.Foo(20) == 18 i.Foo(5) == 6 i.Foo(3) == 6 Is this something that can be done with the Interval library, or am I missing the point? :) Thanks in advance for your help! David Brownell

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Import Error: DLL load Failed
by Shukla, Nitin (Export) 24 Jan '04

24 Jan '04

Hello, I fairly new to the Boost tool. I have just build the Boost.Python 1.30.2. To get started I used the examples "getting_started1.cpp and getting_started2.cpp." and build the required DLLs using the bjam tool. I get following error when I try to import the module "getting_started1" into python : "ImportError: DLL load failed: The specified module could not be found." Can someone help me resolve this error? I am using PythonWin 2.2.1. Nitin

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RE: [Boost-users] MultiArray questions
by Neil Mackie 23 Jan '04

23 Jan '04

I'm responding to Mark Phillips series of questions about MultiArray. I began using MultiArray last year and quickly realised I was unclear how to use the library. Posting to this list did not help and I resorted to emailing the developer. He had not responded, as he is not subscribed to this list. However he was helpful in answering my questions. My advice is to follow the same procedure as I did, contact details are available at http://www.boost.org/libs/multi_array/doc/index.html although the email address I used was garcia at cs dot indiana .edu. Please post your replies back to the list as I too wonder about the efficiency of MultiArray. It is nice to see a well formed set of questions and I look forward to seeing an equally clear set of answers. Regards, Neil (J Mackie). *********************************************************************************** Ofcom is the regulator for the UK communications industry, with responsibilities across television, radio, telecommunications and wireless communications services. Ofcom exists to further the interests of citizen-consumers as the communications industries enter the digital age. Ofcom has taken over the responsibilities and assumed the powers of the five former regulators it has replaced - the Broadcasting Standards Commission, the Independent Television Commission, Oftel, the Radio Authority and the Radiocommunications Agency. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. This footer also confirms that this email message has been scanned for the presence of computer viruses. Any views expressed in this message are those of the individual sender, except where the sender specifies and with authority, states them to be the views of Ofcom. ***********************************************************************************

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jweb
by Emre Turkay 21 Jan '04

21 Jan '04

Hi All, I was trying to compile the boost-graph library documentation (pdf) and I've done the following, and got the error shown. -bash-2.05b$ pwd /home/emre/boost/boost-1.30.2/libs/graph/doc -bash-2.05b$ make jweb -np isomorphism-impl-v3.w make: jweb: Command not found make: *** [isomorphism-impl-v3.tex] Error 127 -bash-2.05b$ Can someone tell me what this "jweb" is ? Thanks, emre

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RE: [Boost-users] tuple problems 2
by Ben Hutchings 19 Jan '04

19 Jan '04

Programmer_blabla <Programmer_blabla(a)hotmail.com> wrote: > Ok thank you, I will post this on microsoft.public.vc.language. > > About the other thing, I originally thinked about that. But what to > specifiy, using the typedef's won't work either (see below): > > int i; > boost::tuple<int> data(27); > > i = boost::tuples::get<0, boost::tuple<int>::head_type, > boost::tuple<int>::tail_type>(data); //ok > i = boost::bind(&boost::tuples::get<0, boost::tuple<int>::head_type, > boost::tuple<int>::tail_type>, _1)(data); //error <snip> Yes, I see, there's ambiguity as to whether this means template<int N, class HT, class TT> typename access_traits<typename element<N, cons<HT, TT> >::type> ::non_const_type get(cons<HT, TT> & c); or template<int N, class HT, class TT> typename access_traits<typename element<N, cons<HT, TT> >::type> ::const_type get(const cons<HT, TT> & c); You can resolve the ambiguity by writing: typedef const int & const_int_getter( const boost::tuple<int>::inherited &); i = boost::bind(static_cast<const_int_getter *>(&boost::get<0>), _1) (data);

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Converting from const to non-const with iterator_adaptor
by Keith MacDonald 19 Jan '04

19 Jan '04

Hi, I'm stuck trying to use iterator_adaptor from the CVS head. I simply want to derive a non-const iterator from a const one derived from iterator_facade, as shown in the code below. When I compile it with VC7.1, the line marked "/* *ERROR* */" generates one of those impenetratable error messages that starts with: cannot convert from 'const Node' to 'boost::iterator_facade<Derived,Value,CategoryOrTraversal,Reference,Differen ce>::reference' If I delete that line, so the default is used, dereferencing a non-const iterator returns a const Node. This seems such a simple requirement that there must be an easy way to do it. What am I doing wrong? Thanks, Keith MacDonald /* ========================= Code Begins ========================= */ #include <boost/iterator/iterator_facade.hpp> #include <boost/iterator/iterator_adaptor.hpp> class Node { // ... // Iteration: public: class iterator; class const_iterator; // Read-only, bidirectional iterator: typedef boost::iterator_facade< const_iterator, const Node, std::bidirectional_iterator_tag > boost_const_iterator; class const_iterator : public boost_const_iterator { public: const_iterator() {} const_iterator(const iterator& it) : m_pNode(it.base().m_pNode) {} explicit const_iterator(const Node* pNode) : m_pNode(pNode) {} friend class iterator; friend class boost::iterator_core_access; private: // Interface required by iterator_facade: reference dereference() const { return *m_pNode; } void increment() { m_pNode = m_pNode->next(); } void decrement() { m_pNode = m_pNode->prev(); } bool equal(const_iterator it) const { return m_pNode == it.m_pNode; } protected: const Node* m_pNode; }; // Read-write, bidirectional iterator, // adapted from const_iterator: typedef boost::iterator_adaptor< iterator, const_iterator, Node /* *ERROR* */ > iterator_base; class iterator : public iterator_base { public: iterator() {} explicit iterator(Node* pNode) : iterator_base(const_iterator(pNode)) {} }; const_iterator begin() const { return const_iterator(m_pChild); } const_iterator end() const { return const_iterator(NULL); } iterator begin() { return iterator(m_pChild); } iterator end() { return iterator(NULL); } private: Node* m_pChild; Node* m_pPrev; Node* m_pNext; }; /* ========================= Code Ends ========================= */

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