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Seeking example of using quaternion class
by yg-boost-users＠m.gmane.org 23 May '02

23 May '02

Hi, I am trying to use the quaternion class for 3d rotation and wonder if anyone has a sample of how to do this. If we have quaterion q1 and want to rotate by q2 the expression, I believe, is result = q2 * q1 * inv( q2 ). Is the correct syntax using ::boost::quaternion operators result = q2 *= q1 /= q2 ?? Do the quats need to be "unit quaternions" before these operations? What is the best way to create an unit quat? thanks john ware

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Re: [boost] boost::lexical_cast string to string problem - New proposition available
by Terje Slettebø 23 May '02

23 May '02

(This posting is also sent to the Boost list) Following a suggestion at the Boost User's list, I've updated the lexical_cast version in the Boost files section (http://groups.yahoo.com/group/boost/files/lexical_cast_proposition/) to use implicit conversion, where possible. This means it uses the fastest and most accurate conversion available, and only resorts to using stringstream when it has to. It uses boost::is_convertible for this. Even if that may not work on all compilers, if it doesn't work, it will just resort to using stringstream. However, this does mean that the semantics is changed slightly. In the cases where an implicit conversion exists, it may give a different result than if not, in the case of char/wchar_t. Without implict conversion, you get 1 -> '1'. With implicit conversion, you get 1 -> 1 (ASCII 1). As far as I can tell, this only affects conversions between char/wchar_t and other types, though. If this is a problem, please let me know, and I can change it to make an exception for char/wchar_t. Another thing is that there's now an option to configure the interpreter stream, as well. This is done _without_ changing the interface of lexical_cast. Instead, it's done in a trait-like fashion, by making the interpreter object available through an associated component, which is used by lexical_cast. The reason this is optional, is that when enabled, it relies on having a static stringstream object. This has two effects (unless implicit conversion is used): - It may well make lexical_cast faster, as it avoids the creation and destruction of a stringstream object, each time it's called. - Unless stringstream is reentrant, which is probably not the case, it means that when the option is enabled, lexical_cast is not thread safe. Therefore, this option is off by default, which gives the usual behaviour - stringstream objects are created at the function call. If the option is used, it lets you configure the stream used, in any way. This way, one can implement all the features of the "wish list" in the previous posting in this thread, such as. - wlexical_cast - A version that can use wide characters - This is already handled by the previous version. - basic_lexical_cast - A version that takes the interpreter (stringstream) as a parameter, to support things like changing locale - Being able to set number base (dec, oct or hex). This would be implicitly possible using basic_lexical_cast - Being able to set precision for numerical conversions. This may also be done with basic_lexical_cast - These are all handled now. - Checking for change of sign, when using unsigned numbers. This is addressed using an integer adapter, in the other lexical_cast_propositions The lack of formatting is what is largely the reason I haven't used lexical_cast much. With control over the formatting, it may be more widely applicable. Since the stream may be different, for different conversions (char, wchar_t or other character type), one need to supply the source and destination types, when configuring the stream. Here's an example of its use. --- Start --- #define BOOST_LEXICAL_CAST_STREAM // Enables stream configuration #include <iostream> #include <iomanip> #include <string> #include "lexical_cast.hpp" int main() { boost::lexical_cast_stream<std::string,double>::stream() << std::setprecision(0); std::cout << boost::lexical_cast<std::string>(1.0/3.0) << '\n'; boost::lexical_cast_stream<std::string,double>::stream() << std::setprecision(10); std::cout << boost::lexical_cast<std::string>(1.0/3.0) << '\n'; boost::lexical_cast_stream<std::string,int>::stream() << std::setbase(16); std::cout << boost::lexical_cast<std::string>(0x1234) << '\n'; } --- End --- This prints. 0.333333 0.3333333333 1234 Any suggestions for changes or additions, including interface changes, is welcome. I realise that the way to change the stream formatting is rather long-winded, but I haven't found a shorter way to do it (the name has to be different from lexical_cast, too). Suggestions for alternative ways are welcome. I've not found a way to make the stream configurable, and yet avoid a static stringstream. If the stringstream is created when lexical_cast is called, it means any configuration information is lost. Even if it copied the state from another stream, that other stream would have to exist, such as being static, so that would only move it. Despite the extra code, to handle implicit conversions, where available, by examining the resulting assembly output (from Intel C++), it's in fact able to optimise _all_ of it away, producing indentical code as if built in conversions were used directly. Here's an example. int n; double d=1.23; int main() { n=boost::lexical_cast<int>(d); } 00401084 fld qword ptr [d (00427db0)] 0040108A fstp qword ptr [esp+8] 0040108E mov esi,dword ptr [esp+8] 00401092 mov edx,dword ptr [esp+0Ch] 00401096 mov ecx,edx 00401098 shr ecx,14h 0040109B and ecx,7FFh 004010A1 cmp ecx,3FEh 004010A7 jle main+52h (004010c6) 004010A9 mov eax,edx 004010AB neg ecx 004010AD add ecx,41Eh 004010B3 shld eax,esi,0Bh 004010B7 or eax,80000000h 004010BC shr eax,cl 004010BE test edx,edx 004010C0 jge main+54h (004010c8) 004010C2 neg eax 004010C4 jmp main+54h (004010c8) 004010C6 xor eax,eax 004010C8 mov [n (0042bef8)],eax int n; double d=1.23; int main() { n=d; } 0041AFF0 fld qword ptr [d (00427db0)] 0041AFF6 fstp qword ptr [esp+8] 0041AFFA mov esi,dword ptr [esp+8] 0041AFFE mov edx,dword ptr [esp+0Ch] 0041B002 mov ecx,edx 0041B004 shr ecx,14h 0041B007 and ecx,7FFh 0041B00D cmp ecx,3FEh 0041B013 jle main+1A022h (0041b032) 0041B015 mov eax,edx 0041B017 neg ecx 0041B019 add ecx,41Eh 0041B01F shld eax,esi,0Bh 0041B023 or eax,80000000h 0041B028 shr eax,cl 0041B02A test edx,edx 0041B02C jge main+1A024h (0041b034) 0041B02E neg eax 0041B030 jmp main+1A024h (0041b034) 0041B032 xor eax,eax 0041B034 mov [n (0042b84c)],eax The code is identical. :) Thus, you get a generic conversion, with the speed and accuracy of built in conversions, where that is possible. It's a good thing I have a unit test, so I could do regression testing, to make sure I haven't broken anything. Regards, Terje

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Problems with read_graphviz()
by Paolo Fosser 23 May '02

23 May '02

Hi to everybody, first of all I beg pardon if my English isn't much good: I'm Italian! I'm working with gcc 3.0.1 on a Linux Mandrake sys with kernel 2.4.8. The problem I'm having is that the second call of read_graphviz() in the same program causes a Segmentation fault. What can I do? Thank you in advance, Paolo PS Advices about the language are welcome too ;)

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Boost thread examples
by imi123_1999 22 May '02

22 May '02

Is there any other site from where we can get the example programs illustrating the usage of boost libraries especially threads. I found the example programs present on boost web site not sufficient to fully understand the concepts. So please tell me from where i can get the further information regarding the usage of boost thread library.

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Thread destruction in boost
by giltayar 21 May '02

21 May '02

>From boost:thread documentation, it is clear that deleting a thread does not kill the thread. I very much approve of this. killing a thread is a very "strong" operation. The problem is that there is now no connection between the system thread and the object itself, which (debatably) kills the idiom in C++ connection the object and the resource (I never remember its name). Was the idea of doing a "join()" in the dtor brought up? I.e., the dtor waiting for the thread to finish? I used it in my library, and it was _very_ effective, as I could _know_ that the thread and the object have parallel lifetimes, and it also helped me because it prevented many "thread-leakage" problems. Gil P.S. The question was - "Was the idea of doing a join() in the dtor ever brought up?"

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RE: [Boost-Users] boost::lexical_cast string to string problem
by Tom Matelich 21 May '02

21 May '02

I and many others have requested fixes for this for a very long time. Basically, it involves creating class templates to do the actual conversion. It's not the most complicated system, just nobody has done it yet. If you search the boost list archives, you'll see a lot of mail about this. There is no quick solution to your problem though. -----Original Message----- From: Jason Fischl [mailto:yg-boost-users@m.gmane.org] Sent: Monday, May 20, 2002 5:21 PM To: boost-users(a)yahoogroups.com Subject: [Boost-Users] boost::lexical_cast string to string problem I'm seeing a problem with lexical_cast. The following code when trying to convert from string to string fails when passed an empty string. The library code that is doing this lexical_cast does not and can not know that the input and output types are the same. I believe that this code should not throw. #include <iostream> #include <boost/lexical_cast.hpp> main() { std::string input(""); try { boost::lexical_cast<std::string>(input); } catch (boost::bad_lexical_cast& e) { std::cout << "Failed" << std::endl; } } Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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random::mersenne_twister ctor and seed() methods
by klapshin 21 May '02

21 May '02

Hello All! I just started using boost/random project, and kind of confused with behavior of random::mersenne_twister constructor and seed method. The thing is that both of them have two flavors -- first accepting DataType, while second is template method accepting Generator. The problem is when I am trying innocent boost::mt19937 rng(999); //and/or rng.seed(999); wrong ctor/seed being invoked and I am getting far from crystal clear error message (term does not evaluate to a function). The problem is quite obvious: 999 is of type int, while DataType by default is unsigned long on my platform, so template version of ctor/seed picks this call, and it is failing since 999 is not a generator. So I have to write something like: boost::mt19937 rng(boost::mt19937::result_type(999)); which is kind of cumbersome. Why generator version of seed is not named differently? Say seed_gen? Don't know what to do with constructor though. PS: I am using boost_1_28_0, and MSVC 6.0. Best regards, Kirill Lapshin.

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boost::lexical_cast string to string problem
by Jason Fischl 21 May '02

21 May '02

I'm seeing a problem with lexical_cast. The following code when trying to convert from string to string fails when passed an empty string. The library code that is doing this lexical_cast does not and can not know that the input and output types are the same. I believe that this code should not throw. #include <iostream> #include <boost/lexical_cast.hpp> main() { std::string input(""); try { boost::lexical_cast<std::string>(input); } catch (boost::bad_lexical_cast& e) { std::cout << "Failed" << std::endl; } }

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BLL trouble
by Persson Jonas 21 May '02

21 May '02

Hello, I've just started playing around with BLL and i have some troubles using it with containers of shared_ptr. I have isolated the problem to: void lambdaTest() { using namespace boost::lambda; boost::shared_ptr<int> x(new int(5)); (*_1)(x); } This does not compile with gcc 3.1 on cygwin. If I use plain pointers it works as expected but not for shared_ptr. What am I doing wrong? / Jonas ---------------------------------------------------------------------------- ---- ../../cygwin/usr/local/include/g++-v3/bits/stl_iterator_base_types.h: In instantiation of `std::iterator_traits<boost::s hared_ptr<int> >': ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: 224: instantiated from `boost::lambda::det ail::contentsof_type<boost::shared_ptr<int> >' ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp:50: instantiated from `boost::lambda::detail::IF_type_<b oost::lambda::detail::contentsof_type<boost::shared_ptr<int> > >' ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp:58: instantiated from `boost::lambda::detail::IF_type<tr ue, boost::lambda::detail::contentsof_type<boost::shared_ptr<int> >, boost::lambda::detail::identity_mapping<boost::lamb da::detail::unspecified> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: 317: instantiated from `boost::lambda::ret urn_type_1<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/return_type_traits.hpp:92: instantiated from `boost::lambda::return_type_1 _prot<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:84 : instantiated from `boost::lambda::detail ::unary_rt<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_fun ctor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boos t::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_ type, boost::tuples::null_type>, boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tuples:: null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:25 3: instantiated from `boost::lambda::lambd a_functor_base<boost::lambda::other_action<boost::lambda::contentsof_action> , boost::tuples::tuple<boost::lambda::lambda _functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::n ull_type, boost::tuples::null_type> >::sig<boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_t ype, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' Main.cpp:150: instantiated from here ../../cygwin/usr/local/include/g++-v3/bits/stl_iterator_base_types.h:123: no type named `iterator_category' in `class boost::shared_ptr<int>' ../../cygwin/usr/local/include/g++-v3/bits/stl_iterator_base_types.h:124: no type named `value_type' in `class boost::shared_ptr<int>' ../../cygwin/usr/local/include/g++-v3/bits/stl_iterator_base_types.h:125: no type named `difference_type' in `class boost::shared_ptr<int>' ../../cygwin/usr/local/include/g++-v3/bits/stl_iterator_base_types.h:126: no type named `pointer' in `class boost::shared_ptr<int>' ../../cygwin/usr/local/include/g++-v3/bits/stl_iterator_base_types.h:127: no type named `reference' in `class boost::shared_ptr<int>' ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: In instantiation of `boost::lambda::detail: :contentsof_type<boost::shared_ptr<int> >': ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp:50: instantiated from `boost::lambda::detail::IF_type_<b oost::lambda::detail::contentsof_type<boost::shared_ptr<int> > >' ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp:58: instantiated from `boost::lambda::detail::IF_type<tr ue, boost::lambda::detail::contentsof_type<boost::shared_ptr<int> >, boost::lambda::detail::identity_mapping<boost::lamb da::detail::unspecified> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: 317: instantiated from `boost::lambda::ret urn_type_1<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/return_type_traits.hpp:92: instantiated from `boost::lambda::return_type_1 _prot<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:84 : instantiated from `boost::lambda::detail ::unary_rt<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_fun ctor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boos t::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_ type, boost::tuples::null_type>, boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tuples:: null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:25 3: instantiated from `boost::lambda::lambd a_functor_base<boost::lambda::other_action<boost::lambda::contentsof_action> , boost::tuples::tuple<boost::lambda::lambda _functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::n ull_type, boost::tuples::null_type> >::sig<boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_t ype, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' Main.cpp:150: instantiated from here ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: 224: no type named `reference' in `struct std::iterator_traits<boost::shared_ptr<int> >' ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp: In instantiation of `boost::lambda::detail::IF_type_<boos t::lambda::detail::contentsof_type<boost::shared_ptr<int> > >': ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp:58: instantiated from `boost::lambda::detail::IF_type<tr ue, boost::lambda::detail::contentsof_type<boost::shared_ptr<int> >, boost::lambda::detail::identity_mapping<boost::lamb da::detail::unspecified> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: 317: instantiated from `boost::lambda::ret urn_type_1<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/return_type_traits.hpp:92: instantiated from `boost::lambda::return_type_1 _prot<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:84 : instantiated from `boost::lambda::detail ::unary_rt<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_fun ctor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boos t::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_ type, boost::tuples::null_type>, boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tuples:: null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:25 3: instantiated from `boost::lambda::lambd a_functor_base<boost::lambda::other_action<boost::lambda::contentsof_action> , boost::tuples::tuple<boost::lambda::lambda _functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::n ull_type, boost::tuples::null_type> >::sig<boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_t ype, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' Main.cpp:150: instantiated from here ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp:50: no type named `type' in `struct boost::lambda::detail::contentsof_type<boost::shared_ptr<int> >' ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp: In instantiation of `boost::lambda::detail::IF_type<true, boost::lambda::detail::contentsof_type<boost::shared_ptr<int> >, boost::lambda::detail::identity_mapping<boost::lambda: :detail::unspecified> >': ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: 317: instantiated from `boost::lambda::ret urn_type_1<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/return_type_traits.hpp:92: instantiated from `boost::lambda::return_type_1 _prot<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:84 : instantiated from `boost::lambda::detail ::unary_rt<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_fun ctor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boos t::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_ type, boost::tuples::null_type>, boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tuples:: null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:25 3: instantiated from `boost::lambda::lambd a_functor_base<boost::lambda::other_action<boost::lambda::contentsof_action> , boost::tuples::tuple<boost::lambda::lambda _functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::n ull_type, boost::tuples::null_type> >::sig<boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_t ype, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' Main.cpp:150: instantiated from here ../../libs/boost_1_28_0/boost/lambda/detail/lambda_traits.hpp:58: no type named `type' in `struct boost::lambda::detail::IF_type_<boost::lambda::detail::contentsof_type<boost ::shared_ptr<int> > >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: In instantiation of `boost::lambda::return_ type_1<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>': ../../libs/boost_1_28_0/boost/lambda/detail/return_type_traits.hpp:92: instantiated from `boost::lambda::return_type_1 _prot<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:84 : instantiated from `boost::lambda::detail ::unary_rt<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_fun ctor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boos t::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_ type, boost::tuples::null_type>, boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tuples:: null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:25 3: instantiated from `boost::lambda::lambd a_functor_base<boost::lambda::other_action<boost::lambda::contentsof_action> , boost::tuples::tuple<boost::lambda::lambda _functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::n ull_type, boost::tuples::null_type> >::sig<boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_t ype, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' Main.cpp:150: instantiated from here ../../libs/boost_1_28_0/boost/lambda/detail/operator_return_type_traits.hpp: 317: no type named `type' in `struct boost::lambda::detail::IF_type<true, boost::lambda::detail::contentsof_type<boost::shared_ptr<int> >, boost::lambda::detail::identity_mapping<boost::lambda::detail::unspecified> >' ../../libs/boost_1_28_0/boost/lambda/detail/return_type_traits.hpp: In instantiation of `boost::lambda::return_type_1_pr ot<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::shared_ptr<int>&>': ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:84 : instantiated from `boost::lambda::detail ::unary_rt<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_fun ctor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boos t::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_ type, boost::tuples::null_type>, boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tuples:: null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:25 3: instantiated from `boost::lambda::lambd a_functor_base<boost::lambda::other_action<boost::lambda::contentsof_action> , boost::tuples::tuple<boost::lambda::lambda _functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::n ull_type, boost::tuples::null_type> >::sig<boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_t ype, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' Main.cpp:150: instantiated from here ../../libs/boost_1_28_0/boost/lambda/detail/return_type_traits.hpp:92: no type named `type' in `struct boost::lambda::return_type_1<boost::lambda::other_action<boost::lambda::cont entsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp: In instantiation of `boost::lambda::detail::u nary_rt<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_functo r<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost:: tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_typ e, boost::tuples::null_type>, boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tuples::nul l_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::t uples::null_type, boost::tuples::null_type, boost::tuples::null_type> >': ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:25 3: instantiated from `boost::lambda::lambd a_functor_base<boost::lambda::other_action<boost::lambda::contentsof_action> , boost::tuples::tuple<boost::lambda::lambda _functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::n ull_type, boost::tuples::null_type> >::sig<boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost ::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_t ype, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' Main.cpp:150: instantiated from here ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:84 : no type named `type' in `struct boost::lambda::return_type_1_prot<boost::lambda::other_action<boost::lambda: :contentsof_action>, boost::shared_ptr<int>&>' ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp: In instantiation of `boost::lambda::lambda_fu nctor_base<boost::lambda::other_action<boost::lambda::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_fun ctor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boos t::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_ type, boost::tuples::null_type> >::sig<boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tu ples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >': Main.cpp:150: instantiated from here ../../libs/boost_1_28_0/boost/lambda/detail/operator_lambda_func_base.hpp:25 3: no type named `type' in `class boost::lambda::detail::unary_rt<boost::lambda::other_action<boost::lambda::c ontentsof_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholde r<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, boost::tuples::tuple<boost::shared_ptr<int>&, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >' Main.cpp: In function `void lambdaTest()': Main.cpp:150: no match for call to `(const boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lamb da::other_action<boost::lambda::contentso f_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholde r<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >) (boost::shared_ptr<int>&)' ../../libs/boost_1_28_0/boost/lambda/detail/lambda_functors.hpp:142: candidates are: T::sig<boost::tuples::null_type>::type boost::lambda::lambda_functor<Base>::operator()() const [with T = boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda ::contentsof_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholde r<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >]

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RE: [Boost-Users] Graphs: vertex_index vs. edge_index
by Siegel, Matthew 20 May '02

20 May '02

Hi Jeremy, Thanks for the quick response. As you may or may not recall from last week, I am having the issue with MSVC++, where I can not put more than one property per edge or vertex when defining the graph, that limits the size of the template expansion. Because of this, I have to use external property maps that I create myself. Therefore I need an edge index map internal to the graph. Currently my workaround is to keep an unsigned integer in my class, that gets incremented until there's a free "slot" for the edge to go into. This is to allow the increment of the unsigned int to roll at maximum value. Here's the way I think it should work. I understand the space issues that most people would be concerned about, however if a property_map of edge_index_t is explicitly given in the list of edge properties when the graph is defined, then the map should be created automatically for me, and if an index is not provided on the add_edge() function, the index is incremented in the same fashion. If I'm explicitly adding the edge_index map to my graph, then the space is of no concern to me. Just a thought . . .thanks again, Matt -----Original Message----- From: Jeremy Siek [mailto:jsiek@cs.indiana.edu] Sent: Monday, May 20, 2002 12:01 PM To: 'Boost-Users(a)yahoogroups.com' Subject: Re: [Boost-Users] Graphs: vertex_index vs. edge_index Hi Matt, On Mon, 20 May 2002, Siegel, Matthew wrote: > Please correct me if I'm wrong. It seems as if a vertex_index gets > assigned to a vertex as it's added to the graph automatically. > However, this doesn't seem to be the case for the edge_index. > > Is this correct?? That is mostly correct. The vertex_index gets assigned automatically for adjacency_list with VertexList=vecS but not with VertexList=listS. You are right about edge_index. > I forsee the following problem. With the graph implemented using a > std::vector for both the vertex list and the edge list, if a vertex is > removed from the graph the index is corrected for the > vertex_descriptor to the new, appropriate index. However, if an edge Right. All vertices are re-indexed, so that after the removal the remaining indices go from 0 to num_vertices-1 > is removed, the index for the edge_descriptor will not be corrected > with the removal of an element in the vector. Also, this causes > headaches when using an external property map. The edge index is > linked directly to a location in my map. > > Any solutions for these problems?? The reason edge_index is not provided automatically is because it takes up space (whereas the vertex_index is does not), and some users are concerned about space issues. Anyways, one possible solution is to somehow make it possible for you to specify some code to be executed when an edge is added or removed from the graph, and this code would adjust the edge indices, and perhaps the external storage too. But before I get ahead of myself, could you describe how you currently work around this problem, and perhaps how you'd like to see it work? Cheers, Jeremy ---------------------------------------------------------------------- Jeremy Siek http://www.osl.iu.edu/~jsiek/ Ph.D. Student, Indiana Univ. B'ton email: jsiek(a)osl.iu.edu C++ Booster (http://www.boost.org) office phone: (812) 855-3608 ---------------------------------------------------------------------- Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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