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[signals] slot<Signature>, slot::track() and bind syntactic sugar
by Frank Mori Hess 27 Feb '07

27 Feb '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I've added template parameters to the slot class in thread_safe_signals for specifying its signature, as slot<Signature> or slot1<R, T1>, etc. So now slots can be bound to each other. I've also dropped the automatic discovery of tracked objects, and added slot::track() functions. There is now some syntactic sugar for bind, if a slot constructor is called with more than one argument, then the arguments will automatically be passed through bind(). I tried using bind<R>(), since the slot knows what its result type should be, but gcc gave me ambiguous overload errors when bind<R> was given a function pointer. There is a little test program in the sandbox now too, at boost-sandbox/libs/thread_safe_signals/test/track_test.cpp. I encountered one problem with the bind syntactic sugar, described in the test program's comments. I found the error message unhelpful, therefore it must be a compiler bug :) - -- Frank -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQFF5KRY5vihyNWuA4URAo2mAJ45BAJvKKl8rHPXGsgn7a2fjmDLVQCeLb0R ln07v8CCYxbwE7topMmhZQ4= =4kwy -----END PGP SIGNATURE-----

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[multi index] warning when used in copy constructor: should be explicitly initialized
by Christoph 27 Feb '07

27 Feb '07

Using gcc with option -W I get the following warning when using a Boost.MultiIndex container inside a copy constructor: /usr/local/include/boost-1_33_1/boost/multi_index_container.hpp: In copy constructor 'boost::multi_index::multi_index_container<Value, IndexSpecifierList, Allocator>::multi_index_container(const boost::multi_index::multi_index_container<Value, IndexSpecifierList, Allocator>&) [with Value = ListenMonitor::ListenZeile, IndexSpecifierList = boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::identity<ListenMonitor::ListenZeile>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, Allocator = std::allocator<ListenMonitor::ListenZeile>]': liste.hpp:139: instantiated from here /usr/local/include/boost-1_33_1/boost/multi_index_container.hpp:204: warning: base class 'struct boost::multi_index::detail::header_holder<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<ListenMonitor::ListenZeile> >, boost::multi_index::multi_index_container<ListenMonitor::ListenZeile, boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::identity<ListenMonitor::ListenZeile>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, std::allocator<ListenMonitor::ListenZeile> > >' should be explicitly initialized in the copy constructor The 'ListenMonitori::Listenzeile' stuff is from me. But the issue does not depend on that. I would assume that copying a multi index is not forbidden and using Is there a way to get rid of that warning? I am trying hard to produce warning free code, and in this case I am not sure if the warning is just ugly or if it is a real problem in the code. [gcc --version: gcc (GCC) 4.1.2 20061115 (prerelease) (SUSE Linux) ] I have attached a trivial example that demonstrates the issue. I have modified the example/basic.cpp: I have added a trivial class XXX that contains employee_set. When copying objects of XXX the above warning is issued by gcc. Best regards Christoph

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Possible bugs in date_time package
by Gregory J. Sharp 27 Feb '07

27 Feb '07

I'm trying to use the date_time/ptime module to parse strings. Platform: MacOS X 10.4.7 on Intel Compiler: gcc 4.0.1 I have three potential bugs, so far. Perhaps I'm unreasonable in hoping that the following strings should be acceptable to time_from_string. 1. time_from_string( "2006-12-06" ) != time_from_string( "2006-12-06 00:00:00" ) 2. time_from_string( "2006/12/06" ) throws an exception (probably related to 1) even though time_from_string( "2006,12,06" ) doesn't throw. 3. time_from_string( "2006-12-06 " ) throws an exception because it passes a null string to str_from_delimited_time_duration(), which tries to read the first character of the string, even though there isn't one. I think 1 & 2 are probably caused by parse_delimited_time() doing a split on ' ' and getting nothing to pass to parse_delimited_time_duration(). -- Gregory J. Sharp email: gregor(a)mail.lepp.cornell.edu Wilson Synchrotron Laboratory url: http://www.lepp.cornell.edu/ ~gregor Cornell University ph: +1 607 255 4882 Ithaca, NY 14853 fax: +1 607 255 8062

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multi_index uses serialization?
by Javier Gonzalez 27 Feb '07

27 Feb '07

Hi, I have a simple question. Isn't there a way to create multi_indices without using the serialization library? I don't intend to stream them! thanks, Javier Gonzalez

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State of the Endian library
by Mateusz Loskot 27 Feb '07

27 Feb '07

Hi, What's the state of the Endian library announced [1] by Beman Dawes? Is there any plan to include it to the Boost collection? May be it's already there, but I can not find it? [1] http://thread.gmane.org/gmane.comp.lib.boost.devel/143279 Cheers -- Mateusz Loskot http://mateusz.loskot.net

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shared_ptr and RTTI
by Florin Trofin 27 Feb '07

27 Feb '07

Hello, A few years back, boost::shared_ptr did not require RTTI. I recently discovered that it does now. I understand that there are some benefits that RTTI brings to the new implementation, but I would have expected that there is some compile flag that can be turned on/off. Florin.

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[BGL] How to use an array in bundled property?
by Shufei Fan 27 Feb '07

27 Feb '07

I defined an double array inside bundled vertex property, and have trouble finding ways of accessing it. Neither can I find any where in the document an example on it. Your input will be much appreciated! my graph is defined as follows: struct Node{ // this is hard to access double mode[3]; }; struct Edge{ //no problem access them double nPixels; unsigned short nTh;}; typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::bidirectionalS, Node, Edge> Graph; //Graph object colGraph Graph colGraph; I have no problem with accessing the 'nPixels' in Edge property, boost::property_map<Graph, double Edge::*>::type ew = get(&Edge::nPixels, *colGraph);//edge weight But I am in a great deal of trouble finding ways of accessing 'mode' in Node property. //compiler error here boost::property_map<Graph, double Node::*>::type nm = get(&Node::mode, *colGraph);//node modeerror message is : //---------------------------------------------------- c:\...\xxx.cpp(236) : error C2440: 'initializing' : cannot convert from 'boost::property_map<Graph,Property>::type' to 'boost::bundle_property_map<Graph,Descriptor,Bundle,T>' with [ Graph=boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS,Node,Edge>, Property=double (Node::* )[3] ] and [ Graph=Graph, Descriptor=boost::property_map<Graph,double Node::* >::descriptor, Bundle=Node, T=double ] No constructor could take the source type, or constructor overload resolution was ambiguous//---------------------------------------------------- neither the following works(I added '[3]' in the parameter list): boost::property_map<Graph, double Node::*[3]>::type nm = get(&Node::mode, *colGraph);//node mode This time errors are raised in the 'property.hpp' file, they are: //---------------------------------------------------- c:\Boost\include\boost-1_33_1\boost\pending\property.hpp(40) : error C2825: 'PropertyTag::kind': cannot form a qualified name c:\Boost\include\boost-1_33_1\boost\graph\properties.hpp(198) : see reference to class template instantiation 'boost::property_kind<PropertyTag>' being compiled with [ PropertyTag=double Node::* [3] ] c:\shufei\VCProjects\edison\segm\GA.cpp(236) : see reference to class template instantiation 'boost::property_map<Graph,Property>' being compiled with [ Graph=Graph, Property=double Node::* [3] ]c:\Boost\include\boost-1_33_1\boost\pending\property.hpp(40) : error C2039: 'kind' : is not a member of 'operator``global namespace'''c:\Boost\include\boost-1_33_1\boost\pending\property.hpp(40) : error C2146: syntax error : missing ';' before identifier 'type'c:\Boost\include\boost-1_33_1\boost\pending\property.hpp(40) : error C2955: 'boost::type' : use of class template requires template argument list c:\Boost\include\boost-1_33_1\boost\type.hpp(14) : see declaration of 'boost::type'c:\Boost\include\boost-1_33_1\boost\pending\property.hpp(40) : fatal error C1903: unable to recover from previous error(s); stopping compilation//----------------------------------------------------thanks, _________________________________________________________________ Connect to the next generation of MSN Messenger http://imagine-msn.com/messenger/launch80/default.aspx?locale=en-us&source=…

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faq How to compile graph?
by fcvcnet 27 Feb '07

27 Feb '07

Hi all, I know BGL just a few days. I need yours help. Now I only want to use the graph in the boost1.33.1 , how can I compile the only one component graph in vc6 or vs2005. So much thanks to your detail reply. Thanks again.

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[lambda] beginner's woes
by Imre Palik 27 Feb '07

27 Feb '07

Hi, I try to use boost::lambda in the following function: string build_headers(shared_ptr<connection> conn, vector<wstring> headers) { if (headers.empty()) return ""; return accumulate(++headers.begin(), headers.end(), string(1, '\'') + conn->quote(headers[0]) + '\'', (_1 + ", '" + bind(&connection::quote, var(conn), _2) + '\'')); } and wisual studio gives me the following error message error C2664: 'boost::lambda::bind' : cannot convert parameter 1 from 'overloaded-function' to 'SOCKET' 1> Context does not allow for disambiguation of overloaded function Could anybody help me decypher this message? What is this 'SOCKET' and how does it come into the picture? Thanks ImRe

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[signals] slot with no SlotFunction template parameter
by Frank Mori Hess 26 Feb '07

26 Feb '07

I'm implementing a more feature-full slot class with some of the things that have been discussed recently. In particular, it is templated only on signature. It uses a templated constructor to store the slot function in a pimpl object that is templated by both signature and slot function type. So now I'm about to rip out the SlotFunction parameter everywhere from thread_safe_signals, as there no longer seems to be any need for it. I feel like I might be overlooking something though. Is there any reason to keep it? -- Frank

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