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RE: shared_ptr - implicit conversion to bool
by scleary＠jerviswebb.com 30 Jan '03

30 Jan '03

> From: wasekvesely <vaclav.vesely(a)volny.cz> > > I've found this in "shared_ptr.hpp": > > // implicit conversion to "bool" > typedef T * (this_type::*unspecified_bool_type)() const; > > operator unspecified_bool_type() const // never throws > { return px == 0? 0: &this_type::get; } > > Why this is better than: > > operator bool() const > { return px != 0; } > > What more can I do with somethin like this? Actually, that's used to prevent mistakes; bool is an integral type, so if you add an implicit conversion to bool, then your smart pointer class can participate in integral promotions. Which allows lots of bad code to compile. :) For an example, implicit conversion to an integral type defines all the comparision operators with any other integral-convertible class. e.g., shared_ptr<int> x; scoped_ptr<int> y; (x == y); // does not do what you might expect... For more information on the problem, see the following reference: More Effective C++, Scott Myers :: Item 28 :: Testing Smart Pointers for Nullness or search the Boost developer archives. -Steve

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shared_ptr - implicit conversion to bool
by wasekvesely <vaclav.vesely＠volny.cz> 29 Jan '03

29 Jan '03

Hi, I've found this in "shared_ptr.hpp": // implicit conversion to "bool" typedef T * (this_type::*unspecified_bool_type)() const; operator unspecified_bool_type() const // never throws { return px == 0? 0: &this_type::get; } Why this is better than: operator bool() const { return px != 0; } What more can I do with somethin like this? Thank you, Wasek

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RE: [Boost-Users] Re: Why is <boost::function>::_1 not in namespa ce boost?
by Tom Matelich 29 Jan '03

29 Jan '03

> > I think I agree with Markus that it is in fact broken. It's easy to > imagine dependency scenarios like this: > > lambda <-- libA <-\ > }--> App > bind <-- libB <-/ > > The guy writing App shouldn't have to be aware of the dependency > conflict between libA and libB. Isn't this only a problem within translation units? I suppose lambda and bind might be included in headers from libA and libB into a single translation unit in App, but seems unlikely. ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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Advice on using iterator_adapter
by Rob Smallshire 28 Jan '03

28 Jan '03

Boosters, I have implemented a 'virtual container' class (i.e. it looks and behaves like it contains Objects, but it fact it doesn't) which implements an iterator interface of what are essentially bidirectional iterators. The iterators I have now are not STL compliant and I only have 'mutable' versions of the iterators, with no corresponding const iterators. Some guidance on how to make the best use of boost::iterator adapter would be appreciated to create fully STL compliant iterator/const_iterator pairs: 1) Out current iterators (i.e. the Base type which will be adapted) return smart reference objects when dereferenced, rather than true C++ references to objects. Will iterator adapter work in this situation? 2) Furthermore, can I use the iterator_adapter to adapt our home-grown mutable iterator into a STL compliant const_iterator? Do I simply modify the Reference of the iterator_adapter template type to be a const version of my smart-reference class? Many thanks, Rob

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Why is <boost::function>::_1 not in namespace boost?
by Markus Werle 28 Jan '03

28 Jan '03

Hi! the placeholders in boost/bin/placeholders.hpp are put in an anonymous namespace. This is awkward, since like this they are visible even in places where I do not want them to be so, e.g.: #include <all_of_boost_lambda> #include <all_of_boost_function> // not unlikely to use both [...] { using namespace boost::lambda; std::for_each(v.begin(), v.end(), std::cerr << _1 << constant(' ')); } In such cases the "_1" is ambigous, since boost::lambda::_1 and and <anonymous>::_1 are both visible. This means that code which used to include boost_lambda stuff may change its meaning (or get ambigous) just by including another boost header. Could we not place those placeholders into namespace boost, just to get rid of the ambiguity? Any caveats I overlooked? (using my own placeholder definitions and BOOST_BIND_NO_PLACEHOLDERS is not really a satisfying solution) Markus

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RE: [Boost-Users] Boost 101?
by Ferdinand Prantl 24 Jan '03

24 Jan '03

> From: Beman Dawes [mailto:bdawes@acm.org] > Sent: Thursday, January 23, 2003 02:50 > > At one time we published a header dependency chart, but as Boost grew > it became unwieldy and we no longer produce it. > > There have been past discussions on how to meet this need, and the > consensus is that usually what is required is a library (rather than > header) dependency analysis. Yes, I agree, it is almost impossible considering which files to include and which not with the current size of the boost package. It is sensible to declare explicitely library dependencies (tree) and use them. Nevertheless, I created a perl script some time ago to display header and library dependencies in my library with references to boost headers. I hacked it quickly to work with boost only; if you are interested it is at http://groups.yahoo.com/group/boost/files/hdr_depend. > This would be fairly easy to produce, using a number of Boost's own > libraries, of course:-) > > But the holdup is that it is only a medium priority task, and lately > has been pushed aside in favor of higher priority work. If > someone else wants > to take this one over, I'd be glad to hand it off. We want to do it > entirely in C++, so any Booster can maintain it. Well, currently I'm happily unpacking all boost but I like the idea; for example, for such a project I would like to use smart pointers only... I could spend some time on such a tool if anyone is interested, firstly gathering the requirements and then developing it. Ferda > > --Beman

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Problem with linking to boost::signals
by René Möhring 24 Jan '03

24 Jan '03

I try to use boost signals and have the following code from the tutorial. #include <boost/signal.hpp> #include <iostream> struct HelloWorld { void operator()() const { std::cout << "Hello, World!" << std::endl; } }; int main() { // Signal with no arguments and a void return value boost::signal<void ()> sig; // Connect a HelloWorld slot HelloWorld hello; sig.connect(hello); // Call all of the slots sig(); } This compiles but gives these errors while linking: /usr/bin/ld: warning: libstdc++.so.3, needed by /usr/local/lib//libboost_signals.so, may conflict with libstdc++.so.4 test.o: In function `_ZN5boost4slotINS_8functionIFvvENS_6detail8function8unusableES5_S5_S5_ S5_S5_S5_S5_S5_S5_EEEC1I10HelloWorldEERKT_': test.o(.gnu.linkonce.t._ZN5boost4slotINS_8functionIFvvENS_6detail8funct ion8unusableES5_S5_S5_S5_S5_S5_S5_S5_S5_EEEC1I10HelloWorldEERKT_+0xac): undefined reference to `boost::signals::detail::slot_base::create_connection()' test.o: In function `_ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIiENS_8functionIFvvENS_6 detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_S9_EEE7connectERKNS_4s lotISA_EE': test.o(.gnu.linkonce.t._ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIi ENS_8functionIFvvENS_6detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_ S9_EEE7connectERKNS_4slotISA_EE+0x83): undefined reference to `boost::signals::detail::signal_base_impl::connect_slot(boost::any const&, boost::any const&, std::vector<boost::signals::trackable const*, std::allocator<boost::signals::trackable const*> > const&)' test.o: In function `_ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIiENS_8functionIFvvENS_6 detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_S9_EEEclEv': test.o(.gnu.linkonce.t._ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIi ENS_8functionIFvvENS_6detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_ S9_EEEclEv+0x15): undefined reference to `boost::signals::detail::call_notification::call_notification(boost::sh ared_ptr<boost::signals::detail::signal_base_impl> const&)' test.o(.gnu.linkonce.t._ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIi ENS_8functionIFvvENS_6detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_ S9_EEEclEv+0x155): undefined reference to `boost::signals::detail::call_notification::~call_notification()' test.o(.gnu.linkonce.t._ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIi ENS_8functionIFvvENS_6detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_ S9_EEEclEv+0x1c7): undefined reference to `boost::signals::detail::call_notification::~call_notification()' test.o: In function `_ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIiENS_8functionIFvvENS_6 detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_S9_EEEC2ERKS2_RKS4_': test.o(.gnu.linkonce.t._ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIi ENS_8functionIFvvENS_6detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_ S9_EEEC2ERKS2_RKS4_+0xa6): undefined reference to `boost::signals::detail::signal_base::~signal_base()' test.o: In function `boost::signals::connection::~connection()': test.o(.gnu.linkonce.t._ZN5boost7signals10connectionD1Ev+0x16): undefined reference to `boost::signals::connection::disconnect() const' test.o: In function `boost::signals::detail::signal_base::signal_base(boost::function2<bool, boost::any, boost::any, boost::empty_function_policy, boost::empty_function_mixin, std::allocator<boost::function_base> > const&)': test.o(.gnu.linkonce.t._ZN5boost7signals6detail11signal_baseC2ERKNS_9fu nction2IbNS_3anyES4_NS_21empty_function_policyENS_20empty_function_mixi nESaINS_13function_baseEEEE+0x41): undefined reference to `boost::signals::detail::signal_base_impl::signal_base_impl(boost::func tion2<bool, boost::any, boost::any, boost::empty_function_policy, boost::empty_function_mixin, std::allocator<boost::function_base> > const&)' test.o: In function `_ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIiENS_8functionIFvvENS_6 detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_S9_EEED2Ev': test.o(.gnu.linkonce.t._ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIi ENS_8functionIFvvENS_6detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_ S9_EEED2Ev+0x11): undefined reference to`boost::signals::trackable::~trackable()' test.o(.gnu.linkonce.t._ZN5boost7signal0IvNS_10last_valueIvEEiSt4lessIi ENS_8functionIFvvENS_6detail8function8unusableES9_S9_S9_S9_S9_S9_S9_S9_ S9_EEED2Ev+0x1f): undefined reference to`boost::signals::detail::signal_base::~signal_base()' test.o: In function `void boost::checked_delete<boost::signals::detail::signal_base_impl>(boost:: signals::detail::signal_base_impl*)': test.o(.gnu.linkonce.t._ZN5boost14checked_deleteINS_7signals6detail16si gnal_base_implEEEvPT_+0x19): undefined reference to`boost::signals::detail::signal_base_impl::~signal_base_impl()' My compiler is gcc 3.2 on FreeBSD. g++ -o signals test.cpp -I/usr/local/include -L/usr/local/lib/ -lboost_signals Do you have an idea what I am doing wrong?

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Specifying a case-insensitive rule for a regex algorithm
by Amittai Aviram 23 Jan '03

23 Jan '03

Hi! I am using boost::regex_grep() and boost::regex_search(), and I've figured out how to set a given rule to be case-insensitive when I transform it from a string into a rule -- i.e., -- boost::regex("search[[:space:]]string", boost::regbase::normal | boost::regbase::icase) This is great. But in many regular expression processing environments, you also have the option to specify case-insensitivity (or sensitivity) within the rule string itself. For instance, in Perl, you do it with the /i switch at the end of the rule string, and in some environments you can use (?i) to make the following characters case-insensitive when processed and then (?-i) to switch case sensitivity back on. I didn't see any mention of any such thing in the regex documentation. Is this option not available in boost::regex? Thanks! Amittai Aviram amittai(a)amittai.com

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Problems using date-time library
by Keno 22 Jan '03

22 Jan '03

Greets all, I'm in need of using the Date-Time library but I'm encountering a few issues. I tried compiling the following simple code: ----------------- #include <boost/date_time/gregorian/gregorian.hpp> #include <iostream> using namespace boost::gregorian; int main() { date birthday(1979,3,26); return 0; } ------------------- and got the following error(s): --------------------Configuration: boost_date - Win32 Debug-------------------- Compiling... test_date.cpp d:\softdev\vstudio6\vc98\include\new(35) : warning C4290: C++ Exception Specification ignored Linking... test_date.obj : error LNK2001: unresolved external symbol "public: static unsigned long __cdecl boost::date_time::gregorian_calendar_base<struct boost::date_time::year_month_day_base<class boost::gregorian::greg_year,class boost::gregorian::greg_mon th,class boost::gregorian::greg_day>,unsigned long>::day_number(struct boost::date_time::year_month_day_base<class boost::gregorian::greg_year,class boost::gregorian::greg_month,class boost::gregorian::greg_day> const &)" (?day_number@?$gregorian_ca lendar_base@U?$year_month_day_base@Vgreg_year@gregorian@boost@@Vgreg_month@2 3@Vgreg_day@23@@date_time@boost@@K@date_time@boost@@SAKABU?$year_month_day_b ase@Vgreg_year@gregorian@boost@@Vgreg_month@23@Vgreg_day@23@@23@@Z) Debug/boost_date.exe : fatal error LNK1120: 1 unresolved externals Error executing link.exe. boost_date.exe - 2 error(s), 1 warning(s) ------------------------------- Any clues as to what could be happening here folks?? I'm using MSVC6 with SP5 + STLPort 4.5.3 on WinXP .: Keno :.

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random number lib: msvc6, prob compiling random_demo.cpp w mt19937
by Nick Toze <geeky_nick＠yahoo.co.uk> 15 Jan '03

15 Jan '03

Hello, I had a slight problem compiling random_demo.cpp after I had changed the typedef to: typedef boost::mt19937 base_generator_type; I got this error: --------------------Configuration: random_demo - Win32 Debug-------------------- Compiling... random_demo.cpp d:\c_plus_plus\boost_1_29_0\boost\random\mersenne_twister.hpp(104) : error C2064: term does not evaluate to a function d:\c_plus_plus\boost_1_29_0\boost\random\mersenne_twister.hpp(75) : see reference to function template instantiation 'void __thiscall boost::random::mersenne_twister<unsigned long,624,397,31,-1727483681,11,7,-1658038656,15,-272236544,18,-948 541730>::seed(const unsigned int &)' being compiled Error executing cl.exe. Creating browse info file... random_demo.exe - 1 error(s), 0 warning(s) I fixed it by adding an 'L' to the first line of main, i.e. base_generator_type generator(42Lu);

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Boost/Python: method overloading w/out default args
by Bruce Lowery <bruce_lowery＠yahoo.com> 15 Jan '03

15 Jan '03

Using Boost/Python, how does one overload methods? For instance: struct Bar { void func( const std::string& s ); void func( int i ); }; BOOST_PYTHON_MODULE( Foo ) { class_<Bar>( "Bar" ) .def( "func", &Bar::func ) .def( ??? ) ; } The reference documentation discusses the BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS macro, but it only seems to apply to methods with default arguments. --bruce

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Boost/Python: returning internal reference
by Bruce Lowery <bruce_lowery＠yahoo.com> 15 Jan '03

15 Jan '03

I have a simple C++ class that I've wrapped using Boost/Python, v1.29.0 (on Win 2K), and that has a simple accessor returning a const ref to an internal string. In the python interpreter, the accessor raises an exception (see below),whereas another access that returns a copy of the string works. Could someone explain my mistake? --bruce ------ Bar.cpp -------- #include <string> class Bar { public: Bar( const std::string& s ) : m_s( s ) {} std::string get_s_copy() const { return m_s; } const std::string& get_s_ref() const { return m_s; } std::string m_s; }; #include <boost/python.hpp> using namespace boost::python; BOOST_PYTHON_MODULE(Foo) { class_<Bar>( "Bar", init< const std::string& >( args("s") ) ) .def( "get_s_copy", &Bar::get_s_copy ) .def( "get_s_ref", &Bar::get_s_ref, return_internal_reference<>() ) .def_readonly( "m_s", &Bar::m_s ) ; } ----- Python session ---- Python 2.2.2 (#37, Oct 14 2002, 17:02:34) [MSC 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> import Foo >>> bar = Foo.Bar("hello") >>> bar.m_s 'hello' >>> bar.get_s_copy() 'hello' >>> bar.get_s_ref() Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: bad argument type for built-in operation >>>

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Boost/Python: Solaris build errors
by Bruce Lowery <bruce_lowery＠yahoo.com> 15 Jan '03

15 Jan '03

In building the boost/python library on solaris using v6.2.p2 of the sunpro compiler, two compile-time errors occur, one in 'cast.hpp' and the other in 'inheritance.hpp'. Details are below. --bruce ----------------- 1 -------------------- boost/boost/python/cast.hpp: line 65: Error: Default arguments cannot be added in later declarations of the template function in the same scope. 57 template <class Target, class Source> 58 inline Target* downcast(Source* p, yes_convertible) 59 { 60 return static_cast<Target*>(p); 61 } 62 63 template <class Target, class Source> 64 inline Target* downcast(Source* p, no_convertible, boost::type<Target>* = 0) *** 65 { *** 66 typedef typename base_type_traits<Source>::type base; 67 return (Target*)detail::downcast<base>(p, convertible<Source*>::check((base*)0)); 68 } ----------------- 2 -------------------- boost/boost/python/object/inheritance.hpp: line 134: Error: ")" expected instead of ">". 130 template <class Source, class Target> 131 inline void register_conversion( 132 // We need this parameter because CWPro7 can't determine 133 // which is the base reliably. *** 134 bool is_downcast = !cast_generator<Source,Target>::is_upcast *** 132 133 // These parameters shouldn't be used, they're an MSVC bug workaround 134 , Source* = 0, Target* = 0) 135 { 136 typedef typename cast_generator<Source,Target>::type generator; 137 138 add_cast(python::type_id<Source>() 139 , python::type_id<Target>() 140 , &generator::execute 141 , is_downcast); 142 }

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RE: [Boost-Users] [BGL] missing include in boost/graph/kruskal_mi n_spanning_tree.hpp
by bjorn.karlsson＠readsoft.com 13 Jan '03

13 Jan '03

> From: Jeppe N. Madsen [mailto:yg-boost-users@m.gmane.org] > > Hi, > > kruskal_min_spanning_tree uses bgl_named_params defined in > boost/graph/named_function_params.hpp, which is not included.... Fixed in CVS. Thanks! Bjorn

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BGL: filtered graphs, write_graphviz, and out of memory messages
by sa3h1n <sa3h1n＠yahoo.com> 13 Jan '03

13 Jan '03

Hi all: I am seeing a strange interaction between filtered graphs and write_graphviz. Briefly, if I try to write out a filtered graph via write_graphviz, compilation ends with an out-of-memory message. A necessary condition for this to happen is that the value_type of the property map I am filtering cannot be of a native type -- int is ok, std::string is not. Example code is appended below. I am using Codewarrior Dev Tools 8.0 on WinXP Pro. Given that the code does not even compile, I am not sure how to move beyond this point. Any ideas? TIA, - S ----------------------------------------------------------------- #include "boost/config.hpp" #include <fstream.h> #include <iostream> // for std::cout #include <utility> // for std::pair #include <algorithm> // for std::for_each #include "boost/utility.hpp" // for boost::tie #include "boost/graph/graph_traits.hpp" // for boost::graph_traits #include "boost/graph/adjacency_list.hpp" #include "boost/graph/graphviz.hpp" #include "boost/graph/filtered_graph.hpp" using namespace boost; namespace boost { enum edge_prop_t { edge_prop = 389457 }; BOOST_INSTALL_PROPERTY(edge, prop); } template <typename T> struct positive_edge_prop { positive_edge_prop() {}; positive_edge_prop(T t) : m_prop(t) {}; template <typename Edge> bool operator() (const Edge& e) const { return "foo" == get(m_prop, e); } T m_prop; }; int main(void) { // create an edge property // if std::string is replaced with int, and some attendant changes are made, the code compiles typedef property<edge_prop_t, std::string> EdgeProperty; // create a simple graph type typedef adjacency_list<vecS, vecS, bidirectionalS, no_property, EdgeProperty> Pgraph; enum { A, B, C, D, E, F, N }; const int num_vertices = N; typedef std::pair<int, int> Edge; Edge edge_array[] = { Edge(A, B), Edge(B, C), Edge(C, D), Edge(D, E), Edge(E, F), Edge(F, A), }; const int num_edges = sizeof(edge_array)/sizeof(edge_array[0]); Pgraph pg(edge_array, edge_array + num_edges, num_vertices); // Add edge properties typedef boost::property_map<Pgraph, edge_prop_t>::type ewt; ewt ew = get(edge_prop_t(), pg); boost::graph_traits<Pgraph>::edge_iterator ei, ei_end; boost::tie(ei, ei_end) = edges(pg); for (ei; ei != ei_end; ei++) put(ew, *ei, "bar"); std::map<std::string,std::string> graph_attr, vertex_attr, edge_attr; boost::write_graphviz(std::cout, pg); positive_edge_prop<ewt> filter(get(edge_prop_t(), pg)); filtered_graph<Pgraph, positive_edge_prop<ewt> > fg(pg, filter); boost::write_graphviz(std::cout, fg); // if this line is commented out, the code compiles just fine return 0; } -----------------------------------------------------------------

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Next release date???
by Alejandro Escalante Medina 13 Jan '03

13 Jan '03

Does anyone have an idea for the date of the next release??? Thanks, Alex _________________________________________________________ Do You Yahoo!? La mejor conexión a internet y 25MB extra a tu correo por $100 al mes. http://net.yahoo.com.mx

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Problem with g++ 2.95.3 and boost-example file_dependencies.cpp
by Michael Brinkmann 12 Jan '03

12 Jan '03

Hi, I am trying to get the "file_dependencies"-example compiled and running with the g++-version mentioned above. But, in the function "dijkstra_shortest_paths_no_init()" an exception is thrown and the program terminates prematurely. When hunting the bug with gdb, I get the message "Cannot access memory at address ..." for the parameter "weight", perhaps this is the reason for the exception. Is this a known problem? Will an upgrade to a higher g++-version help me, or has someone another hint? Thanks in advance Michael

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threads - using boost.threads in win32 without use of dll?
by Phil Nash 12 Jan '03

12 Jan '03

Hi, I understand that on the win32 platforms boost.threads requires a dll to be build - threadmon. I seem to remember that this is there as a workaround to help support thread local storage (but I can't seem to find mention of it in the docs now, so I am not 100% sure of this). If this is the case, is it possible to use boost.threads *without* the dll if thread local storage is not being used? Regards, [)o IhIL..

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boost::signal and thread-safety
by svanechel <svanechel＠yahoo.com> 11 Jan '03

11 Jan '03

Hi, The signal FAQ says that currently boost::signals aren't thread-safe. I'm guessing this applies to connecting/disconnecting slots from different threads and calling a signal from multiple threadsl, right? If synchronize access when connecting slots and make sure that only a single thread calls a certain signal, can I then use boost::signal to fire events from objects that do processing in a worker thread? As a secondary question: how far in the future will this thread- safety support be added? Thanks in advance, Sven

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[BGL] missing include in boost/graph/kruskal_min_spanning_tree.hpp
by Jeppe N. Madsen 11 Jan '03

11 Jan '03

Hi, kruskal_min_spanning_tree uses bgl_named_params defined in boost/graph/named_function_params.hpp, which is not included.... rgds Jeppe

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(no subject)
by Wilken, Marc 11 Jan '03

11 Jan '03

Hello, does anyone knows, if a construct like out(blitz::Range(0,2))=inp(blitz::Range(0,2)); (that means accesing and assigning of matrix/vector ranges) exist for boost::numeric::ublas too? Marc This e-mail contains confidential information for the exclusive attention of the intended addressee. Any access of third parties to this e-mail is unauthorised. Any use of this e-mail by unintended recipients such as copying, distribution, disclosure etc. is prohibited and may be unlawful. When addressed to our clients the content of this e-mail is subject to the General Terms and Conditions of GL's Group of Companies applicable at the date of this e-mail. GL's Group of Companies does not warrant and/or guarantee that this message at the moment of receipt is authentic, correct and its communication free of errors, interruption etc.

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BGL, vertex_iterators, listS vs vecS
by sa3h1n <sa3h1n＠yahoo.com> 11 Jan '03

11 Jan '03

BGL gurus: I would like to use listS for vertex and edge lists because of iterator stability. However, if I run the following code: ------------ // use listS typedef adjacency_list<listS, listS> Pgraph; // use vecS typedef adjacency_list<vecS, vecS> Pgraph2; int num_vertices = 2; Pgraph pg (num_vertices); boost::graph_traits<Pgraph>::vertex_iterator vi, vi_end; boost::tie(vi, vi_end) = vertices(pg); Pgraph2 pg2 (num_vertices); boost::graph_traits<Pgraph2>::vertex_iterator vi2, vi_end2; boost::tie(vi2, vi_end2) = vertices(pg2); for (vi, vi2; vi != vi_end && vi2 != vi_end2; vi++, vi2++) { std::cout << *vi << std::endl; std::cout << *vi2 << std::endl; } ------------ I get the following output: ------------ 0x00146e60 <- this is *vi which uses listS 0 <- this is *vi2 which uses vecS 0x00146e78 <- this is *vi which uses listS 1 <- this is *vi2 which uses vecS ------------ One of the problems with this is when I try to display the graph using write_graphviz. Vertex indices turn out be 0x0014e60 etc instead of nice numbers like 0, 1, etc. Tracing execution through the debugger, it appears that vi and vi_end are of type generic_iterator(), whereas vi2 and vi2_end are of type iterator_adaptor() defined in boost/iterator_adaptors.hpp . Unfortunately, this is where my c++ expertise peters out. So what is happenning here? And is there anything I can do to ensure iterator stability while using vecS? Any help will be much appreciated, S

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Re: [boost] boost version 1.27 and 1_25_0
by David Abrahams 10 Jan '03

10 Jan '03

Chunhui Pan <chpan(a)milkyway.gsfc.nasa.gov> writes: > Hi, > > If anyone can give an instruction on how to build > boost 1.27 lib and boost_1_25_0 lib on Red Hat7.2? 1.27 instructions are at: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/boost/boost/tools… And 1.25 instructions are at: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/boost/boost/tools… HTH, -- David Abrahams dave(a)boost-consulting.com * http://www.boost-consulting.com Boost support, enhancements, training, and commercial distribution

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multi_array dinamically built
by Ramón Casero Cañas 10 Jan '03

10 Jan '03

Hi, I would like to dinamically create a multi_array. Something like typedef boost::multi_array<bool, 2> BoolMatrix; typedef boost::multi_array<bool, 2>::index indexBoolMatrix; boost::array<BoolMatrix::index, 2> shape = {{ 5, 8 }}; BoolMatrix *A; // NO MEMORY ALLOCATED ... A = new BoolMatrix(shape); // MEMORY ALLOCATED A.assign(data,data+40); // ELEMENTS INITIALIZED The compiler (gcc 2.95.4) says that this kind of things are wrong. Or didn't I understand how the memory allocation in multi_array works? Cheers, Ramón.

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NEWBIE - building on linux
by gcs_99 <gregsteele＠woodsidenet.com> 10 Jan '03

10 Jan '03

Can anyone point me to directions for building boost under linux. I have installed bjam. When I type bjam -sTOOLS=gcc in my boost root dir I get tons of errors. I understand that much of boost is implemented as templates in header files. Is there an install script to place these in the correct location for gcc? Thanks. G

4 6

request for solaris/forte toolset jamfile
by Dr Bruce Lowery <bruce_lowery＠yahoo.com> 10 Jan '03

10 Jan '03

If anyone has a somewhat working jamfile for solaris/forte, could you post a copy of it? --bruce

4 3

Installing boost regex
by Alisdair Meredith 10 Jan '03

10 Jan '03

We're (still!) in the process up upgrading our software to the latest borland compiler, BCB6 I am now at the stage of trying to get the boost libraries integrated into our builds. After running bjam I get some libboost_regex libs, but these don't seem to be used. Reading the separate install procedure under the regex library, I find another install procedure that produces a set of libraries targetted at BCB that do solve my problems. Is this the correct procedure? Is there any way to integrate this with the jam scripts in the future? If not, should we add a link under installing boost to the separate procedure for the regex libraries? -- AlisdairM Team Thai Kingdom

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stop a thread
by hlh771 <hlh771＠yahoo.com.cn> 10 Jan '03

10 Jan '03

How to stop(or cancel) a thread? Suppose I have a main thread and a worker thread, the worker thread does something looply,and when the main thread get a message indicating the process should exit, I want stop the worker thread,how to do that?I have read other thread library,their thread class supply a method called stop or cancel which stops the thread. Their Implementation is:the thread class has a data member indicating whether the thread should stop,and the thread function looply check the data member whether the thread should stop.Generally the data member's type is a bool or Event. Is it the best way to stop the thread? How the boost to deal with this? Thanks in advance.

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Starting to use unit tests
by Scott Nesbitt 10 Jan '03

10 Jan '03

I am in to process of adding the boost test framework to our project, and am looking for advice or samples for how best to do this. Specifically, we have multiple executables sharing several libraries. I was thinking about having a different test suite for each library, but don't see much documentation on using multiple test suites. Any advice or pointers? Thanks, Scott Nesbitt scott.nesbitt(a)yahoo.com __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com

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bind() and argument_type?
by Duane Murphy 09 Jan '03

09 Jan '03

I am trying to use bind() with std::not1() (I think this is what I want to do :-). But std::not1() gets a compiler error because bind doesnt have an argument_type typedef. bool is_something( int x, int y ) { return something( x, y ); } { ... if ( std::not1( boost::bind( is_something, 3, _1 ) ) ) { // not something } } Am I approaching this incorrectly? Does bind support argument_type? Thanks for the advice, ...Duane

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RE: [Boost-Users] Problem with BOOST_STATIC_ASSERT
by Randy Bowen 09 Jan '03

09 Jan '03

Thanks to John and Richard Cox for investigating this. > You will be pleased to know that it works correctly with VC7.1. > > John Maddock.

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RE: [Boost-Users] Problem with BOOST_STATIC_ASSERT
by Randy Bowen 09 Jan '03

09 Jan '03

Thanks for investigating this, John. I don't have access to the beta VC7.1 compiler. Do you (or does anyone else) know if this will still be a problem with the forthcoming version of the Microsoft compiler? Randy Bowen -----Original Message----- From: John Maddock [mailto:john_maddock@compuserve.com] Sent: Wednesday, January 08, 2003 4:17 AM To: Boost-Users(a)yahoogroups.com Subject: Re: [Boost-Users] Problem with BOOST_STATIC_ASSERT > Some further follow-up on this. I've created a minimal program that > exhibits the new problem behavior: > > /******************************************/ > #include <boost/type_traits.hpp> > #include <boost/static_assert.hpp> > > template < typename ValueType > > struct A > { > BOOST_STATIC_ASSERT(boost::is_integral<ValueType>::value); > }; > > extern "C" int main(int argc, char* argv[]) > { > return 0; > } > /******************************************/ > > The fact that this assertion fails is counter-intuitive to me, since > there is no instantiation to compile. Note that this behavior seems > limited to the use of "is_integral" as the type predicate. Constructing > a similar program using "is_POD" behaves as expected: I can reproduce that with both VC6 and VC7, all the other compilers I have access to are OK with it. It's clearly a compiler bug, because the assert is triggered even though no instance of the template class is ever created. Unfortunately I don't have any kind of workaround :-( John Maddock http://ourworld.compuserve.com/homepages/john_maddock/index.htm Yahoo! Groups Sponsor ADVERTISEMENT 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 the Yahoo! Terms of Service.

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RE: [Boost-Users] Problem with BOOST_STATIC_ASSERT
by richard_cox＠dell.com 09 Jan '03

09 Jan '03

On Wednesday, January 08, 2003 5:29 PM, Randy Bowen [mailto:rbowen@stamps.com] wrote: > -----Original Message----- > From: > Sent: > To: Boost-Users(a)yahoogroups.com > Subject: RE: [Boost-Users] Problem with BOOST_STATIC_ASSERT > > > Thanks for investigating this, John. I don't have access to > the beta VC7.1 compiler. Do you (or does anyone else) know > if this will still be a problem with the forthcoming version > of the Microsoft compiler? > > Randy Bowen > > > > -----Original Message----- > From: John Maddock [mailto:john_maddock@compuserve.com] > Sent: Wednesday, January 08, 2003 4:17 AM > To: Boost-Users(a)yahoogroups.com > Subject: Re: [Boost-Users] Problem with BOOST_STATIC_ASSERT > > > > Some further follow-up on this. I've created a minimal > program that > > exhibits the new problem behavior: > > > > /******************************************/ > > #include <boost/type_traits.hpp> > > #include <boost/static_assert.hpp> > > > > template < typename ValueType > > > struct A > > { > > BOOST_STATIC_ASSERT(boost::is_integral<ValueType>::value); > > }; > > > > extern "C" int main(int argc, char* argv[]) > > { > > return 0; > > } > > /******************************************/ > > > > The fact that this assertion fails is counter-intuitive to > me, since > > there is no instantiation to compile. Note that this > behavior seems > > limited to the use of "is_integral" as the type predicate. > Constructing > > a similar program using "is_POD" behaves as expected: > > I can reproduce that with both VC6 and VC7, all the other > compilers I have access to are OK with it. It's clearly a > compiler bug, because the assert is triggered even though no > instance of the template class is ever created. Unfortunately > I don't have any kind of workaround :-( > > John Maddock > http://ourworld.compuserve.com/homepages/john_maddock/index.ht m The code as quoted built without error OK on VC++7.1 RC2 (Final Beta) here... using snapshot of boost taken last weekend. Richard Cox Senior Software Developer Dell Technology Online All opinions and statements mine and do not in any way (unless expressly stated) imply anything at all on behalf of my employer

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Re: [Boost-Users] Re: Re: Slight Alteration to Boost Directory Structure
by William E. Kempf 09 Jan '03

09 Jan '03

> From: "Simon Bailey <conic(a)bigpond.com>" <conic(a)bigpond.com> > --- In Boost-Users(a)yahoogroups.com, "Paul Mensonides" <yg-boost- > users@m...> wrote: > > "William E. Kempf" <wekempf@c...> wrote in message > > > > > That still misses the point. Boost currently won't help you to > install > > the library, but installation certainly wouldn't entail copying the > entire > > $BOOST_ROOT tree to the $INCLUDE directory on your system. You'd > only copy > > the $BOOST_ROOT/boost tree there. > > > > Yes, and this is why I said that it hasn't been a problem for me. > However, > > I see where the OP is coming from as well. > > > > Paul Mensonides > > Paul understands me correctly. I confused the issue by making two > requests at once. > > Mainly, I want to include other libraries alongside boost and provide > a single include path. That is the first wish. Bill has pointed out > that I could move BOOST_ROOT/boost into my INCLUDE directory. I > didn't know that - I thought it might break things. > > The second thing I was suggesting (and this is quite minor) was that > we make the change to include smart_ptr.hpp (etc.) and thread.hpp > (etc.) at the same directory level. I thought that the > subdirectories (like /thread) were the way of the future. I didn't > realise that the plan was to move all the headers into > BOOST_ROOT/boost. > > So it seems my first wish is not needed and my second wish is already > on the drawing board. :-) No, it's never been planned to move all headers into $BOOST_ROOT/boost. That would be problematic at best. The headers are in subdirectories to avoid name clashes, and that's how it should be for large libraries and/or libraries that use common names. What many of these libraries do, and what Boost.Threads will do with the next release, however, is to have a *single* include header in $BOOST_ROOT/boost that includes all the other headers from the specific sub-library. This (mostly) avoids the dangers of name clashes, gives a simple single include file for many uses, yet retains the ability for users to include only what they need to in order to reduce compilation time, etc. For example, both of the following would be legal: #include <boost/thread/thread.hpp> #include <boost/thread/mutex.hpp> #include <boost/thread/condition.hpp> // ... code using boost::thread, boost::mutex and // boost condition - or - #include <boost/thread.hpp> // ... code using boost::thread, boost::mutex and // boost condition William E. Kempf wekempf(a)cox.net

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Re: [Boost-Users] Re: Re: Slight Alteration to Boost Directory Structure
by William E. Kempf 09 Jan '03

09 Jan '03

> From: "Simon Bailey <conic(a)bigpond.com>" <conic(a)bigpond.com> > Suddenly I remember why I wanted the directory structure change... > > I could achieve what I want by moving BOOST_ROOT/boost into my > INCLUDE directory. But the disadvantage with that is that I need to > perform a move operation. > > *** In my current development environment, my source control > directory structure mirrors my release directory structure exactly. > *** > > So, in source control I have: > > /include > --/BOOST_ROOT > ----/boost <- headers are here > --/my_lib <- headers are here > > But, in my release I want to have: > /include > ----/boost <- headers are here > ----/my_lib <- headers are here > > I was suggesting the change so that source control and relase could > be the same. This would necessitate that documentation and source > for boost would have to be within the boost (include) directory. > Some might find that a worse alternative I suppose. I think most would. I know I do. William E. Kempf wekempf(a)cox.net

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which boost lib to use for generic list sort by member function ?
by Philippe Guglielmetti 09 Jan '03

09 Jan '03

I try to define a "sortby" method that would sort a list using any member function that fits some constraints (taking no parms, returning a result that can be compared using the > operator and being const) I wrote this: template <class T> class mylist:public std::list<T> { // ... template <typename T2, typename R, R (T2::*F)() const> struct cmp: public std::binary_function<T,T,bool> { bool operator()(const T& f1, const T& f2) {return (f1.F)() > (f2.F)();}; }; template <typename T2, typename R> bool sortby(R (T2::*F)() const) { sort(cmp<T,R,F>()); return true; }; }; // class mylist using VC6 (I know...) I get these 3 errors: algos.h(356) : error C2440: 'specialization' : cannot convert from 'double (__thiscall cadoo::cadFace::*)(void) const' to 'double (__thiscall cadoo::cadFace::*)(void)' algos.h(356) : error C2975: 'cmp' : invalid template argument for 'F', constant expression expected algos.h(356) : error C2514: 'dyl::List<class cadoo::cadFace>::cmp<class cadoo::cadFace,double,0>' : class has no constructors any idea ? I also checked boost.org for help on functors, lambda ... but could not figure out how to use them simply for my application. thanks! Philippe Guglielmetti

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Boost::python + vc + sgistl problem
by yg-boost-users＠m.gmane.org 09 Jan '03

09 Jan '03

I use Boost::Python module with VC and SGI stl. But I got some compile errors like mix\max redefine.... Who know how to solve this problem??? -- CNews 0.4

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HELP: Command line sample.
by Lichun Bao 09 Jan '03

09 Jan '03

Hi, Can someone please provide a sample single command line compile using g++ that generates the final executable binary for a test example? For example, in the unpacked BOOST directory, how to do something like: g++ <options> libs/graph/example/bfs-example.cpp -o \ /tmp/bfs-example for the final executable? Thanks, Lichun

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Re: [Boost-Users] Boostifying GluCat
by William E. Kempf 08 Jan '03

08 Jan '03

Sorry folks, this posting never should have made the list. As one of the moderators, I hit the wrong button here. Sorry for any inconvenience. William E. Kempf wekempf(a)cox.net

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Boostifying GluCat
by Paul C. Leopardi 08 Jan '03

08 Jan '03

Bjorn, GluCat is a new numeric template class library, hopefully destined for promotion to Boost. I would like to know where there is some documentation on how to: 1. Add concepts. Is there such a thing as a non-commutative algebra concept? How do I check concepts? 2. Add numeric limits. Limits of eg. framed_multi<T> would default to limits of T. 3. Add numeric promotion_traits. What are promotion_traits ? There is currently a discussion on ublas-dev mailing list about promotion_traits within uBLAS. 3. Add numeric type_traits. Thanks On Thu, 9 Jan 2003 00:18, you wrote: > Paul, > unfortunately this post is off topic for Boost-Users, and is thus > rejected. While it may well be of interest to some of our subscribers, > and the usage of uBLAS is a nice success story, we do not allow > announcement postings - only topics related to usage of Boost libraries. > > Regards, > Bjorn Karlsson > Moderator

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Re: [Boost-Users] Re: Re: Slight Alteration to Boost Directory Structure
by William E. Kempf 08 Jan '03

08 Jan '03

> From: "Paul Mensonides" <yg-boost-users(a)m.gmane.org> > "William E. Kempf" <wekempf(a)cox.net> wrote in message > news:20030108172855.VIMZ4411.lakemtao01.cox.net@smtp.east.cox.net... > > > > I believe that he is talking about the root Boost directory which is the > > > parent directory of the Boost headers. If, for instance, I have a > directory > > > "include" that I want to put all my library headers in and have a single > > > environment variable to specify the header search paths. This cannot be > > > done with Boost because the Boost headers are located at > > > "boost/boost/*.hpp", not "boost/*.hpp". Furthermore, you can't even put > > > Boost in the same directory as other includes, because you might get a > > > conflict between "include/boost" and "include/boost/boost". It doesn't > > > bother me personally, but I see the point that he is getting at. > > > > If that's the point (which doesn't seem to be, since he talks about "new > boost libraries" doing the right thing), I can't agree. Moving Boost > headers out of a boost subdirectory and into the top-level include directory > (so <boost/shared_ptr.hpp> becomes <shared_ptr.hpp>) would only result in > name clashes with other headers. > > That is not what he (or I) means. He is suggesting that the path to > "shared_ptr.hpp" should be "$INCLUDE/boost/shared_ptr.hpp" rather than > "$INCLUDE/boost/boost/shared_ptr.hpp", which is the way it is now. > Everything would still be the same for including headers except that only a > single search path is necessary to setup with the compiler. That's the way it is now *only* if you set your include directories incorrectly. When they are properly set to $BOOST_ROOT then it's only <boost/shared_ptr.hpp>, not <boost/boost/shared_ptr.hpp>. William E. Kempf wekempf(a)cox.net

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Re: [Boost-Users] Re: Slight Alteration to Boost Directory Structure
by William E. Kempf 08 Jan '03

08 Jan '03

> From: "Paul Mensonides" <yg-boost-users(a)m.gmane.org> > Date: 2003/01/08 Wed PM 12:18:35 EST > To: boost-users(a)yahoogroups.com > Subject: [Boost-Users] Re: Slight Alteration to Boost Directory Structure > > "William E. Kempf" <wekempf(a)cox.net> wrote in message > > > > 2. Each library bundled with boost means another #include search > > > path needs to be added. > > > > No, there's only one path added for all Boost libraries, > $BOOST_ROOT/boost. > > Here I think he is talking about libraries other than Boost. How can anything we do to the Boost directory structure effect this? I don't really think that's what he meant. > > > Proposed solution: > > > 1. Create a single boost include directory instead of having the two > > > nested ones that there are now. > > > > What two nested ones? > > I believe that he is talking about the root Boost directory which is the > parent directory of the Boost headers. If, for instance, I have a directory > "include" that I want to put all my library headers in and have a single > environment variable to specify the header search paths. This cannot be > done with Boost because the Boost headers are located at > "boost/boost/*.hpp", not "boost/*.hpp". Furthermore, you can't even put > Boost in the same directory as other includes, because you might get a > conflict between "include/boost" and "include/boost/boost". It doesn't > bother me personally, but I see the point that he is getting at. If that's the point (which doesn't seem to be, since he talks about "new boost libraries" doing the right thing), I can't agree. Moving Boost headers out of a boost subdirectory and into the top-level include directory (so <boost/shared_ptr.hpp> becomes <shared_ptr.hpp>) would only result in name clashes with other headers. William E. Kempf wekempf(a)cox.net

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Re: [Boost-Users] Slight Alteration to Boost Directory Structure
by William E. Kempf 08 Jan '03

08 Jan '03

> From: "Simon Bailey <conic(a)bigpond.com>" <conic(a)bigpond.com> > > I've been using boost for about a year now. I upgraded from 27 to > 28 and appreciated the backwards compatability. But I'm wondering > if a slight modification to the directory structure is in order? > > I have written a cross-platform class library. The library provides > high-level business objects and comes bundled with boost 1.28.0 to > provide support for threads, CRC, shared_ptr, and function (or > whatever else the end user might want). > > Currently, users need to add two directories to their #include > search path: > include/boost > include/sb_library > > Then, in their source code: > #include <boost/shared_ptr.hpp> > #include <boost/thread/thread.hpp> > #include <sb_library/business_facet/business_object.h> > > Two problems (albeit very minor ones!) > 1. Boost has two levels of includes (due to it's history of course). Two levels? There's only one, $BOOST_ROOT/boost. To avoid name clashes, many libraries are located in library specific directories off of this, as you see with <boost/thread/thread.hpp>. Something that many libraries do (and Boost.Threads will be updated to do shortly) is to have a single header in the root include directory that includes all of the headers from the library directory, thus for Boost.Threads you'd include only <boost/thread.hpp> instead of <boost/thread/thread.hpp>, <boost/thread/mutex.hpp> etc. > 2. Each library bundled with boost means another #include search > path needs to be added. No, there's only one path added for all Boost libraries, $BOOST_ROOT/boost. > Proposed solution: > 1. Create a single boost include directory instead of having the two > nested ones that there are now. What two nested ones? > 2. Put all boost headers into a sub-directory of boost > eg <boost/ptr/shared_ptr.hpp>, <boost/thread/thread.hpp>. (It's a > small change for existing users to change their includes). This is mostly how it is now... though many headers don't live in library specific subdirectories (which is probably how it should be). > 3. Place all src, documentation etc. into a directory within boost > called "private" or something. > > Suggested directory structure: > > --include // This is the only directory needed to be specified in > the #include search path > ----other_library1 > ----other_library2 > ----boost > -------ptr > -------thread > -------private > ----------documentation > ----------src > ----------thread > > In other words, you will have <boost/ptr/...> and <boost/thread/...> > but never <boost/private/...>. This is just a variation on what's currently done, and I can't see how it buys you anything, and actually is a more confusing layout IMHO. > I think it's worth breaking the backwards compatability a little in > order to bring the older boost headers in line with the directory > structure of the newer ones like thread. I also think enabling a > single include path for multiple libraries is useful. Boost.Threads followed existing directory guidelines (as do all libraries). There's no difference between it and "older" libraries (note that Boost.Threads is not that new). William E. Kempf wekempf(a)cox.net

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is_convertible and array size question
by globeordi＠free.fr 08 Jan '03

08 Jan '03

Hello all, Just perhaps a silly question but who knows ? I have a small class that encapsulates a char[] type such as: template <const unsigned int n> struct C_Array { enum { size = n }; typedef char (&Array)[size]; typedef const char (&ConstArray)[size]; C_Array() { memset(&v[0], 0, 30); v[0] = '6'; v[1] = '7'; v[2] = '8'; v[3] = '9'; } char v[n]; int toto; char & operator[](const unsigned int i) { return v[i]; } const char & operator[](const unsigned int i) const { return v[i]; } operator Array () { return v; } operator ConstArray () const { return v; } }; Thanks to the operator Array, the objects of this class can be converted to references to arrays and the following pseudo-code works fine as expected: C_Array<30> obj; cout << boost::is_convertible<obj, char[]>::value << endl; But what I want to get is the actual size of the converted array. In the example the size is 30. It is not very important (workaround exists), just curious to see how it can be done without telling to compiler more information. Best regards Joseph Canedo

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RE: [Boost-Users] Problem with BOOST_STATIC_ASSERT
by Randy Bowen 08 Jan '03

08 Jan '03

Some further follow-up on this. I've created a minimal program that exhibits the new problem behavior: /******************************************/ #include <boost/type_traits.hpp> #include <boost/static_assert.hpp> template < typename ValueType > struct A { BOOST_STATIC_ASSERT(boost::is_integral<ValueType>::value); }; extern "C" int main(int argc, char* argv[]) { return 0; } /******************************************/ The fact that this assertion fails is counter-intuitive to me, since there is no instantiation to compile. Note that this behavior seems limited to the use of "is_integral" as the type predicate. Constructing a similar program using "is_POD" behaves as expected: /******************************************/ #include <boost/type_traits.hpp> #include <boost/static_assert.hpp> template < typename ValueType > struct B { BOOST_STATIC_ASSERT(boost::is_POD<ValueType>::value); }; struct C {}; extern "C" int main(int argc, char* argv[]) { // B<int> Bint; /* OK to add */ // B<C> BC; /* causes error */ return 0; } /******************************************/ Here, no error occurs until there is an attempt to instantiate B<C>. Randy Bowen -----Original Message----- From: Randy Bowen Sent: Tuesday, January 07, 2003 1:40 PM To: Boost-Users(a)yahoogroups.com Subject: [Boost-Users] Problem with BOOST_STATIC_ASSERT I'm in the process of updating some applications from use of Boost 1.28.0 to 1.29.0, using MSVC7. I've noticed that a number of static assertions that used to compile now generate errors. The assertions all use is_integral to perform a type validation - e.g.: BOOST_STATIC_ASSERT(::boost::is_integral<value_type>::value); This produces an error of the form: c:\Perforce\Development\Web\cppinclude\domestic\Application Framework\State Machine Engine\StringSerializer.h(145) : error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' with [ x=false ] c:\Perforce\Development\Web\cppinclude\domestic\Application Framework\State Machine Engine\StringSerializer.h(143) : see reference to class template instantiation 'sme::StringSerializer<_StringType,>::StringWriter<<template parameter>>' being compiled c:\Perforce\Development\Web\cppinclude\domestic\Application Framework\State Machine Engine\StringSerializer.h(169) : see reference to class template instantiation 'sme::StringSerializer<_StringType,>' being compiled I believe that the data type is integral, and is complete at compile time. Any known reason why this would happen? Randy Bowen

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Severe bugs in lambda/algorithm.cpp
by Markus Werle 08 Jan '03

08 Jan '03

Hi! I wonder whether this file ever was included by anyone else but me and which compiler did let this pass without complaint. Besides the #include <utilities> which never ever happens we have 2 errors in struct count struct count { template <class Args> struct sig { typename ::std::iterator_traits< // **************************************************** // ERROR: typedef is not allowed here typedef typename boost::remove_const< typename boost::tuples::element<1, Args>::type >::type >::difference_type type // ERROR: semicolon missing }; Same errors in count_if beginning at line 172. ----------------------------------------------------- In line 613: a duplicate parameter name c operator()(A a, B b, C c, D c) const Same on line 681 best regards, Markus

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lambda/algorithm.hpp: #include <utilities>?
by Markus Werle 08 Jan '03

08 Jan '03

Hi! Line 23 in lambda/algorithm.hpp reads #include <utilities> // for std::pair IMHO (and that of intel's C++ and SGI's documentation) this line should be #include <utility> // for std::pair right? best regards, Markus

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Slight Alteration to Boost Directory Structure
by Simon Bailey <conic＠bigpond.com> 07 Jan '03

07 Jan '03

I've been using boost for about a year now. I upgraded from 27 to 28 and appreciated the backwards compatability. But I'm wondering if a slight modification to the directory structure is in order? I have written a cross-platform class library. The library provides high-level business objects and comes bundled with boost 1.28.0 to provide support for threads, CRC, shared_ptr, and function (or whatever else the end user might want). Currently, users need to add two directories to their #include search path: include/boost include/sb_library Then, in their source code: #include <boost/shared_ptr.hpp> #include <boost/thread/thread.hpp> #include <sb_library/business_facet/business_object.h> Two problems (albeit very minor ones!) 1. Boost has two levels of includes (due to it's history of course). 2. Each library bundled with boost means another #include search path needs to be added. Proposed solution: 1. Create a single boost include directory instead of having the two nested ones that there are now. 2. Put all boost headers into a sub-directory of boost eg <boost/ptr/shared_ptr.hpp>, <boost/thread/thread.hpp>. (It's a small change for existing users to change their includes). 3. Place all src, documentation etc. into a directory within boost called "private" or something. Suggested directory structure: --include // This is the only directory needed to be specified in the #include search path ----other_library1 ----other_library2 ----boost -------ptr -------thread -------private ----------documentation ----------src ----------thread In other words, you will have <boost/ptr/...> and <boost/thread/...> but never <boost/private/...>. I think it's worth breaking the backwards compatability a little in order to bring the older boost headers in line with the directory structure of the newer ones like thread. I also think enabling a single include path for multiple libraries is useful. Cheers Simon

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Problem with BOOST_STATIC_ASSERT
by Randy Bowen 07 Jan '03

07 Jan '03

I'm in the process of updating some applications from use of Boost 1.28.0 to 1.29.0, using MSVC7. I've noticed that a number of static assertions that used to compile now generate errors. The assertions all use is_integral to perform a type validation - e.g.: BOOST_STATIC_ASSERT(::boost::is_integral<value_type>::value); This produces an error of the form: c:\Perforce\Development\Web\cppinclude\domestic\Application Framework\State Machine Engine\StringSerializer.h(145) : error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' with [ x=false ] c:\Perforce\Development\Web\cppinclude\domestic\Application Framework\State Machine Engine\StringSerializer.h(143) : see reference to class template instantiation 'sme::StringSerializer<_StringType,>::StringWriter<<template parameter>>' being compiled c:\Perforce\Development\Web\cppinclude\domestic\Application Framework\State Machine Engine\StringSerializer.h(169) : see reference to class template instantiation 'sme::StringSerializer<_StringType,>' being compiled I believe that the data type is integral, and is complete at compile time. Any known reason why this would happen? Randy Bowen

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uBLAS - Calculation of Inverse and/or Least Squares
by jonny5cents <jon_nichols95＠hotmail.com> 07 Jan '03

07 Jan '03

Hello All, Can anyone suggest the best way to use uBLAS to calculate the inverse of a matrix?? One of the reasons I want to do this is to solve a linear least squares problem, which I know can be done without explicitly solving for the inverse. Does anyone know if this is possible?? thanks, jon

3 2

ublas - newbie question and comment
by Mike Hayford 07 Jan '03

07 Jan '03

I discovered uBLAS a week ago and am very impressed by the design and implementation of the library. To learn the library I have been porting a few non-linear least squares codes from FORTRAN into uBLAS. A real hinderance is the documentation. There is no user's guide or set of example code to orient the new user to uBLAS. Some of the most valuable features are undocumented - such as scalar_vector, vector_indirect, and matrix_indirect. The widespread adoption of uBLAS by the C++ numeric community would be more rapid if these omissions were addressed. I would be willing to write up some of the *simple* examples I have done, if people think it would be useful. If my implementations can be improved, that would be even better. I'm new to Boost and haven't yet completely RTFM'd the requirements for Boost doc contributions so point me in the right direction if I'm going astray here. Having said that, I have a specific problem I'm trying to solve. I'm looking for the best "uBLAS-style" solution - I can do an element-by-element brute force solution. Problem: write the product of a diagonal matrix and a vector when the diagonal matrix is stored as a vector. So what I want to do figuratively is: int n = 5; vector<double> x(n), y(n), diag(n); diagonal_matrix<double> dMat(n); dMat = diag; x = prod(dMat, y); Is there a matrix adaptor of some sort that can fill the role of diagonal_matrix<> above? I looked in the header files and didn't see anything obvious. Thanks in adavance for your help. Mike Hayford --------------------------------- Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now [Non-text portions of this message have been removed]

3 2

[date_time] error C2782: _STL::abs() : template parameter 'T' is ambiguous
by Nick Toze <geeky_nick＠yahoo.co.uk> 06 Jan '03

06 Jan '03

Hello, Seems a bit similar to an earlier post, but this is using msvc6. The ambiguity is with "stlport\stl\_complex.h" (version 4.5.3). The error is: d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(33) : error C2782: ' __cdecl _STL::abs()' : template parameter 'T' is ambiguous could be 'long double' or 'const struct _STL::complex<long double> &' d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(33) : error C2785: ' __cdecl _STL::abs()' and 'long double __cdecl _STL::abs(const struct _STL::complex<long double> &)' have different return types d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(30) : see declaration of 'abs' d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(33) : error C2782: ' __cdecl _STL::abs()' : template parameter 'T' is ambiguous could be 'double' or 'const struct _STL::complex<double> &' d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(33) : error C2785: ' __cdecl _STL::abs()' and 'double __cdecl _STL::abs(const struct _STL::complex<double> &)' have different return types d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(30) : see declaration of 'abs' d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(33) : error C2782: ' __cdecl _STL::abs()' : template parameter 'T' is ambiguous could be 'float' or 'const struct _STL::complex<float> &' d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(33) : error C2785: ' __cdecl _STL::abs()' and 'float __cdecl _STL::abs(const struct _STL::complex<float> &)' have different return types d:\c_plus_plus\boost_1_29_0\boost\date_time\compiler_config.hpp(30) : see declaration of 'abs'

1 0

error C2668: 'abs' : ambiguous call to overloaded function
by Black Ice 06 Jan '03

06 Jan '03

boost version 2002-01-02 VC 7.1 Final Beta "error C2668: 'abs' : ambiguous call to overloaded function" when compile following code. The same code can be built successfully in vc6. Any suggestion are appreciated. #define DATE_TIME_INLINE #define BOOST_DATE_TIME_POSIX_TIME_STD_CONFIG #include <iostream> #include <string> using namespace std; #include <boost/date_time/gregorian/gregorian.hpp> #include <boost/date_time/posix_time/posix_time.hpp> using namespace boost::gregorian; using namespace boost::posix_time; void testDateTime2() { date d(2002, Nov, 1); //an arbitrary date ptime t1(d, hours(5) + nanosec(100));//date + time of day offset ptime t2 = t1 - minutes(4)+seconds(2); ptime now = second_clock::local_time(); //use the clock //Get the date part out of the time date today = now.date(); date tommorrow = today + date_duration(1); ptime tommorrow_start(tommorrow); //midnight cout << "d is " << to_iso_extended_string(d) << endl; cout << "t1 is " << to_iso_extended_string(t1) << endl; cout << "t2 is " << to_iso_extended_string(t2) << endl; cout << "now is " << to_iso_extended_string(now) << endl; cout << "today is " << to_iso_extended_string(today) << endl; cout << "tommorrow is " << to_iso_extended_string(tommorrow) << endl; cout << "tommorrow_start is " << to_iso_extended_string(tommorrow_start) << endl; //starting at current time iterator adds by one hour time_iterator titr(now,hours(1)); for (; titr < tommorrow_start; ++titr) { cout << to_iso_extended_string(*titr) << endl; } } -- /*******************/ ×ÔÓÉ£šliberty£©ÎÞ·ÇŸÍÊÇÕâÑùÒ»ÖÖ³ÐÅµ£ºÃ¿žöÈËœ«»áµÃµœÒ»ÖÖ±£ÕÏ£¬±£ÕÏÎÒÃÇ¿ÉÒÔÓë ÈšÍþ¡¢¶àÊý¡¢Á÷Ë×Œ°ÓßÂÛµÄÓ°ÏìÏà¿¹ºâ¡£ /*******************/

4 8

RE: [Boost-Users] Re: error C2668: 'abs' : ambiguous call to overloaded function
by Jeff Garland 06 Jan '03

06 Jan '03

> After I move the line 'using std namespace', the error still occurs. > The error occurs in file date_time/time_duration.hpp, line 66. > min_type minutes() const > { > return std::abs(((ticks() / (60*rep_type::res_adjust())) % 60)); > } > It seems like the abs function declared in boost/date_time/compiler_config. hpp will not be included due to the macro configuration. The relavant code snippet is: //boost/date_time/compiler_config.hpp //Work around compilers that don't have std::abs #if (__GNUC__ <= 3)|| (defined(BOOST_MSVC) && _MSC_VER <= 1200) # define BOOST_NO_LONG_LONG_ABS #endif #if defined(BOOST_NO_LONG_LONG_ABS) namespace std { template <typename T> // JDG [7/6/02 made a template] inline T abs(T x) { return x < 0 ? -x : x; } } #endif You might try altering this so that the function will be defined. Something like (line 22) #if (__GNUC__ <= 3)|| defined(BOOST_MSVC) should do the trick. The only thing is that past testing with newer versions of MSVC did not require this so I'm a bit suprised that this is needed. This will only work if the problem is that the compiler is trying to convert the underlying type boost::int64_t into a long or another type because it lacks a std::abs for this type. Jeff

2 2

Re: [Boost-Users] Re: error C2668: 'abs' : ambiguous call to overloade
by martynl＠cix.compulink.co.uk 06 Jan '03

06 Jan '03

In-Reply-To: <av5tpc$fmj$1(a)main.gmane.org> Black Ice, > After I move the line 'using std namespace', the error still occurs. > The error occurs in file date_time/time_duration.hpp, line 66. > min_type minutes() const > { > return std::abs(((ticks() / (60*rep_type::res_adjust())) % 60)); > } For VC++ 7.1, we've enabled by default conformant overloads of abs that were previously disabled by default. As a result, you'll need to cast the result of your math to a specific type to ensure you get the abs you want. Martyn Lovell Software Architect Visual C++ Team - Libraries email: lnytram(a)tfosorcim.moc [Spam-avoidance: reverse each word in the email address before use] This posting is provided "AS IS" with no warranties, and confers no rights.

2 1

Compile error when build boost with vc 7 and vc 7.1
by Black Ice 04 Jan '03

04 Jan '03

The last version of boost has got by CVS. set BOOST_ROOT=d:\boost\boost set VC7_ROOT=D:\Program Files\Microsoft Visual Studio .NET 2003\Vc7 bjam "-sTOOLS=vc7" Command line error D2016 : '/Za' and '/Ze' command-line options are incompatible -- /*******************/ ×ÔÓÉ£šliberty£©ÎÞ·ÇŸÍÊÇÕâÑùÒ»ÖÖ³ÐÅµ£ºÃ¿žöÈËœ«»áµÃµœÒ»ÖÖ±£ÕÏ£¬±£ÕÏÎÒÃÇ¿ÉÒÔÓë ÈšÍþ¡¢¶àÊý¡¢Á÷Ë×Œ°ÓßÂÛµÄÓ°ÏìÏà¿¹ºâ¡£ /*******************/

5 9

auto_array?
by Duane Murphy 04 Jan '03

04 Jan '03

Is there a class filling in the missing piece to the memory management puzzle for an auto_array? We have: scoped_ptr and scoped_array, shared_ptr and shared_arry, and auto_ptr. I would like to have an auto_array. Basically the feature that is missing is to create an array, initialize it and then transfer ownership as a way of managing exceptions during the initialization phase. For the time being I am using a shared_array. Thank for any suggestions. ...Duane

1 1

Re: [Boost-Users] Re: Re: Re: Slight Alteration to Boost Directory Structure
by William E. Kempf 04 Jan '03

04 Jan '03

> From: "Paul Mensonides" <yg-boost-users(a)m.gmane.org> > "William E. Kempf" <wekempf(a)cox.net> wrote in message > news:20030108174453.YIAW22825.lakemtao04.cox.net@smtp.east.cox.net... > > > > That is not what he (or I) means. He is suggesting that the path to > > > "shared_ptr.hpp" should be "$INCLUDE/boost/shared_ptr.hpp" rather than > > > "$INCLUDE/boost/boost/shared_ptr.hpp", which is the way it is now. > > > Everything would still be the same for including headers except that > only a > > > single search path is necessary to setup with the compiler. > > > > That's the way it is now *only* if you set your include directories > incorrectly. When they are properly set to $BOOST_ROOT then it's only > <boost/shared_ptr.hpp>, not <boost/boost/shared_ptr.hpp>. > > ...which is precisely the point. You have to have a separate include > directory for Boost, rather than a single directory which contains various > libraries. I.e. it would be nice to have a directory structure like this: > > $INCLUDE/ > Loki/*.* > Boost/*.* > > And then have only a single header directory: $INCLUDE. I'm not talking > about the paths in the source code (i.e. <boost/shared_ptr.hpp>); I'm > talking about the include directories that the compiler searches, which is > external to the source code. That still misses the point. Boost currently won't help you to install the library, but installation certainly wouldn't entail copying the entire $BOOST_ROOT tree to the $INCLUDE directory on your system. You'd only copy the $BOOST_ROOT/boost tree there. William E. Kempf wekempf(a)cox.net

5 5

RegEx: (?= ) and (?! )
by Yutaka Emura <yutaka＠emurasoft.com> 02 Jan '03

02 Jan '03

Hi, I am using RegEx in Boost v1.29.0. (?= ) and (?! ) expressions do not seem to work at a certain condition. In the following example, "(?=a)b" should match "b" in "xyzabcdefg", but does not. Similarly, "(?!a)b" should not match "b" in "xyzabcdefg" but it does. Can please let me know what is wrong? Thank you for your reply in advance. Yutaka Emura --------- boost::regex expression; boost::match_results<std::string::const_iterator> subexp; expression.assign("(?=a)b", boost::regbase::perl); if (boost::regex_search((std::string::const_iterator)"xyzabcdefg", (std::string::const_iterator)"xyzabcdefg" + 10, subexp, expression, boost::match_default)) { { // should go here } else { // goes here } expression.assign("(!=a)b", boost::regbase::perl); if (boost::regex_search((std::string::const_iterator)"xyzabcdefg", (std::string::const_iterator)"xyzabcdefg" + 10, subexp, expression, boost::match_default)) { { // goes here } else { // should go here }

3 2

concept check warnings
by s_j_turner <s_j_turner＠yahoo.co.uk> 02 Jan '03

02 Jan '03

FWIW, I just started looking at Jeremy Siek's concept checking tools, and my compiler(*) came up with a warning about name hiding which is trivial to fix. I was using ContainerConcept, and it uses a method argument with the same name as a data member. The fix looks like: *** concept_check.hpp Fri Dec 27 16:51:51 2002 --- concept_check.hpp Thu Jan 2 16:13:03 2003 *************** *** 708,719 **** function_requires< AssignableConcept<Container> >(); const_constraints(c); } ! void const_constraints(const Container& c) { ! i = c.begin(); ! i = c.end(); ! n = c.size(); ! n = c.max_size(); ! b = c.empty(); } Container c; bool b; --- 708,719 ---- function_requires< AssignableConcept<Container> >(); const_constraints(c); } ! void const_constraints(const Container& cc) { ! i = cc.begin(); ! i = cc.end(); ! n = cc.size(); ! n = cc.max_size(); ! b = cc.empty(); } Container c; bool b; There are a few other classes in there which do the same thing, but this is the only one I'm currently using. --- (*) Sun Forte 6.2.1

1 0

RE: [Boost-Users] Re: Simple boost program throws exception
by Tom Matelich 02 Jan '03

02 Jan '03

I don't have too much advice except a) try the latest boost b) put a try/catch block around the code, figure out what function is calling and what exception is being thrown. > -----Original Message----- > From: ksaleh2 <ksaleh2(a)yahoo.com> [mailto:ksaleh2@yahoo.com] > Sent: Wednesday, January 01, 2003 9:21 AM > To: Boost-Users(a)yahoogroups.com > Subject: [Boost-Users] Re: Simple boost program throws exception > > > Hi, > > On December 7th I've posted this message, which unfortunately didn't > get any reply. I'm not a professional programmer, so forgive me if it > is a silly question, but your cooperation will help me understand > boost better, thank you and happy new year to all. > > --- In Boost-Users(a)yahoogroups.com, "ksaleh2 <ksaleh2@y...>" > <ksaleh2@y...> wrote: > > I'm trying boost for the first time on Codewarrior 8.0 for windows. > > The Boost version is 1.25.1 from the "Boost Graph Library" > > accompanying CD. The offensive code is : > > > > #include <boost/config.hpp> > > #include <iostream> > > > > #include <boost/graph/adjacency_list.hpp> > > > > using namespace boost; > > using namespace std; > > > > > > int main() > > { > > typedef adjacency_list<vecS,vecS,directedS, > > property < vertex_name_t, char > >,property<edge_weight_t,double> > > > Graph; > > > > property_map < Graph, vertex_name_t >::type name_map ; > > property_map < Graph, edge_weight_t >::type value_map ; > > > > Graph g; > > > > typename graph_traits<Graph>::vertex_descriptor a,b; > > > > a = add_vertex(g); name_map[a] = 'a'; > > b = add_vertex(g); name_map[b] = 'b'; > > > > typename graph_traits<Graph>::edge_descriptor ed; > > bool inserted; > > > > tie(ed, inserted) = add_edge(a, b, g); > > value_map[ed] = 1.2; > > > > > > return 0; > > } > > > > > > If the second template parameter for class VertexListS is replaced > > with listS it compiles and run normally. > > > > typedef adjacency_list<vecS,listS,directedS, > > property < vertex_name_t, char > >,property<edge_weight_t,double> > > > Graph; > > > > Can you please advise why? > > > > Best Regards > > > > ------------------------ Yahoo! Groups Sponsor > ---------------------~--> > Flexible Keyboard is the ideal accessory for PDA users that > are on the move. > http://us.click.yahoo.com/dCBVZC/WnCFAA/xGHJAA/EbFolB/TM > -------------------------------------------------------------- > -------~-> > > 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/ ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

1 0

Error in testing tuple
by agiatojon <JonAgiato＠nyc.rr.com> 01 Jan '03

01 Jan '03

Happy Holidays to everyone! I am getting aquainted with the tuple class but am encountering the following error: c:\BGL\boost_1_29_0\boost\tuple\tuple_comparison.hpp(119): error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' with [ x=false ] with the following program: /** * tupleTest.cpp * Test of Boost library class tuple * A tuple is a fixed size collection of elements * Stored objects may be of different types * Current support of tuples with 0-10 objects * Objects may be any valid C++ type except void and function types * Jon Agiato * 12-23-02 */ #include <iostream> using std::cout; using std::cin; using std::ostream; using std::cerr; #include <cstdlib> #include <boost/tuple/tuple.hpp> using boost::tuple; // both tuple_io.hpp and tuple_comparison.hpp include tuple.hpp // tuple_io must be included for tuple input and output operators #include <boost/tuple/tuple_io.hpp> // tuple_comparison.hpp must be included for comparison operators #include <boost/tuple/tuple_comparison.hpp> #include <string> using std::string; #include <exception> using std::exception; class A { friend ostream &operator<<(ostream &output, const A &a) { output << a.S; return output; } public: A(string s = "Testing"):S(s) {;} string S; }; class B { friend ostream &operator<<(ostream &output, const B &b) { output << b.D; return output; } public: B(double d = 3.501):D(d) {;} double D; }; class C { friend ostream &operator<<(ostream &output, const C &c) { output << c.state; return output; } public: C(bool st = true):state(st) {;} double state; }; int main() { try { tuple<A, B, C> testTuple; cout << testTuple << '\n'; tuple<B, A> test2Tuple; if(testTuple == test2Tuple) cout << testTuple << " is equal to " << test2Tuple << '\n'; else cout << testTuple << " is not equal to " << test2Tuple << '\n'; cout << "Press enter to exit..."; cin.get(); return EXIT_SUCCESS; } catch(const exception &E) { cerr << "Standard library exception: " << E.what() << '\n'; return EXIT_FAILURE; } catch(...) { cerr << "Unknown exception thrown.\n"; return EXIT_FAILURE; } } I am using Visual Studio.NET Enterprise Architect Thanks! Jon Agiato JonAgiato(a)nyc.rr.com

3 2

Simple boost program throws exception
by ksaleh2 <ksaleh2＠yahoo.com> 01 Jan '03

01 Jan '03

I'm trying boost for the first time on Codewarrior 8.0 for windows. The Boost version is 1.25.1 from the "Boost Graph Library" accompanying CD. The offensive code is : #include <boost/config.hpp> #include <iostream> #include <boost/graph/adjacency_list.hpp> using namespace boost; using namespace std; int main() { typedef adjacency_list<vecS,vecS,directedS, property < vertex_name_t, char >,property<edge_weight_t,double> > Graph; property_map < Graph, vertex_name_t >::type name_map ; property_map < Graph, edge_weight_t >::type value_map ; Graph g; typename graph_traits<Graph>::vertex_descriptor a,b; a = add_vertex(g); name_map[a] = 'a'; b = add_vertex(g); name_map[b] = 'b'; typename graph_traits<Graph>::edge_descriptor ed; bool inserted; tie(ed, inserted) = add_edge(a, b, g); value_map[ed] = 1.2; return 0; } If the second template parameter for class VertexListS is replaced with listS it compiles and run normally. typedef adjacency_list<vecS,listS,directedS, property < vertex_name_t, char >,property<edge_weight_t,double> > Graph; Can you please advise why? Best Regards

1 1

Success stories
by Miki_Tebeka＠amat.com 01 Jan '03

01 Jan '03

Hello All, I'm trying to convince my boss to use boost. Any helpful success stories/big users/anything that can help? 10x. Bye. ----------------------------------------------------------------------------- Smile, damn it, smile. lambda msg: { 'name' : 'Miki Tebeka', 'email' : 'miki_tebeka(a)amat.com', 'url' : 'http://www.cs.bgu.ac.il/~tebeka', 'quote' : 'The only difference between children and adults is the price of the toys' }[msg]

3 2

shared_ptr and VC++ .net
by mwong <cmwong＠cedara.com> 30 Dec '02

30 Dec '02

Hi, I was trying to compile the following code using VC++ .NET. #include "stdafx.h" #include "boost/smart_ptr.hpp" int _tmain(int argc, _TCHAR* argv[]) { boost::shared_ptr<int> spc = new int(0); return 0; } I got the following error messages: c:\boost\smart_ptr.hpp(375) : error C2065: 'T' : undeclared identifier c:\boost\smart_ptr.hpp(375) : error C2687: cannot define a nested UDT of a template class out of line c:\boost\smart_ptr.hpp(375) : fatal error C1903: unable to recover from previous error(s); stopping compilation The offending code in smart_ptr.hpp is: template<typename T> struct less< boost::shared_ptr<T > > //..... LINE 375 : binary_function<boost::shared_ptr<T>, boost::shared_ptr<T>, bool> { bool operator()(const boost::shared_ptr<T>& a, const boost::shared_ptr<T>& b) const { return less<T*>()(a.get(),b.get()); } }; Can someone please tell me what is the problem? I was able to compile the same code using VC++ 6.0. Thanks. Ming

2 1

RE: [Boost-Users] Re: boost::date_time : iterator model
by Jeff Garland 30 Dec '02

30 Dec '02

Dave A wrote: > Jeff, I remember discussing this with you at Oopsla last year -- why > not use the iterator adaptors library to help you build correct > iterators? Bad excuses only. The first date iterators pre-dated iterator adaptors. When I sat down to convert things over it was 'less-than easy'. I read the docs and experimented, but couldn't get things working -- this might have been related to 2.9x series of compilers I was using at the time, but no matter. When I ran out of patience I just dropped it and never got back to it. It has been on my 'todo' list ever since... Jeff

1 0

RE: [Boost-Users] mpl::for_each
by Aleksey Gurtovoy 30 Dec '02

30 Dec '02

Oleg Grunin wrote: > It would be useful IMHO if mpl::for_each took its functor argument by > reference or better yet, became aware of boost::reference_wrapper. Done, the latter, check out the CVS. Thanks for the suggestion! Aleksey

1 0

Error when I tried to compile an example
by g9news02 <g9news02＠yahoo.com.au> 30 Dec '02

30 Dec '02

Hi all, I tried to compile an example provided with the Boost date time library but kept getting the following error message: "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 23: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 23: Error: BOOST_PP_LIST_FOR_EACH_I_M is not defined. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 23: Error: Use ";" to terminate declarations. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 23: Error: Use ";" to terminate declarations. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 26: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 26: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 26: Warning: Too few arguments in macro BOOST_PP_CHECK_2. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 26: Error: BOOST_PP_LIST_FOR_EACH_I_M is not defined. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 26: Error: Use ";" to terminate declarations. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 26: Error: Use ";" to terminate declarations. "/pssource/current/thirdparty/boost/boost_1_29_0/boost/type_traits/is_void.hpp", line 27: Warning: Too few arguments in macro BOOST_PP_CHECK_2. Does anyone know how to fix the problem. Thanks in advance.

1 0

type_traits/is_convertible crashes Forte 6.2u2 and Forte 7.0
by Robert A. Reece 29 Dec '02

29 Dec '02

I put the following line in a file (it's the only line...) #include <boost/type_traits/is_convertible.hpp> And compiled as such: CC -I$BOOST temp.cpp Under both Forte 6.2u2 (running under Solaris 8) and Forte 7.0 (solaris 9), it produces the following: /hades02/pega/pegdevlcl/work> CC -I$PEGDEV3RD/boost/1.29.0 temp.cpp >> Assertion: (../links/init.cc, line 957) while processing /tsgnt1/pegdevsrc/3rd/src/boost/1.29.0/boost/type_traits/is_convertible.hpp at line 118. Has anybody else seen this? I checked the latest CVS archive and didn't see any updates to this file. The odd thing is that line 118 is blank. Thanks -Rob

2 1

mpl::for_each
by Oleg Grunin 29 Dec '02

29 Dec '02

It would be useful IMHO if mpl::for_each took its functor argument by reference or better yet, became aware of boost::reference_wrapper.

2 1

mpl begin end
by Oleg Grunin 29 Dec '02

29 Dec '02

Since mpl algorithms unlike their stl counterparts take sequences not iterators how does one run them on a subset of a container.

2 1

boost::date_time : iterator model
by klapshin <klapshin＠yahoo.com> 29 Dec '02

29 Dec '02

Hello, I am an a process of adapting our codebase to boost date_time library, and one quite annoying problem I encountered is that date iterators conform to InputIterator model, rather then Random Access Iterator. By the nature of application I have to calculate quite often something like current date plus N months. The only way I see so far is doing something like date d(2002,Dec,26); month_iterator mi(d); for( size_t i=0; i < 5; ++i) ++mi; d = *mi; This is rather awkward, not to mention inefficient. I was trying to search both User and Developers mailing lists for "date InputIterator" hoping to find out what was the reason to use InputIterators, but no luck. BTW, how am I supposed to roll few months back? It is a forward iterator not even a bidirectional. Even more critique: the iterator is not exactly InputIterator, since it has only prefix increment, and no postfix one. Best regards, Kirill Lapshin.

6 8

RE: [Boost-Users] Re: boost::date_time : iterator model
by Jeff Garland 28 Dec '02

28 Dec '02

>However I will try to give it a shot. What is the right >place to take latest source code from? Regular Boost CVS >repository on SourceForge? Yes, the boost CVS repository on sourceforge has the latest source. Jeff

1 0

Property maps / Graph library
by rradh <rradh＠yahoo.com> 25 Dec '02

25 Dec '02

Hi, The examples in libs/graph/example have property_map like vertex_name that associates a 'vertex -> user-defined name' (usually a std::string). Without having to use an external std::map, is there any way to create a property_map that provides the reverse association 'user-defined name -> vertex', so that I can retreive the vertex based on the user-defined name and without iterating thru each vertex. Thanks Rajesh

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[BGL] Simplest way to implement bool isReachable(Vertex src, Vert ex target, Graph g) was: [Boost-Users] Re: Extended use of BGL File Depen dency Example
by Tom Matelich 24 Dec '02

24 Dec '02

> From: Tom Matelich [mailto:tmatelich@zetec.com] > > From: Tom Matelich [mailto:tmatelich@zetec.com] > > From: David Abrahams [mailto:dave@boost-consulting.com] > > > Tom Matelich <tmatelich(a)zetec.com> writes: > > > > From: David Abrahams [mailto:dave@boost-consulting.com] > > > >> Tom Matelich <tmatelich(a)zetec.com> writes: > > > >> > > > >> > trying to make my graphviz representation look nicer and I > > > >> was wondering if > > > >> > there is an algorithm already for simplifying: > > > > > > > > -----B\ > > > > A--< \ > > > > --------C > > > > D----------/ > > > > > > > > to: > > > > > > > > A---B---C > > > > D------/ > > > > > > > > This eliminated the A-C edge. <snip discussion of minimum spanning tree. It won't work because I require all reachability to be maintained. > so here's my psuedo-algorithm: for each vertex V for each out-edge E for each out-edge E_prime (double loop) if(isReachable(target(E_prime), target(E)) remove_edge(E) In other words if one of V's children can reach the target vertex of a given edge, then that edge can be removed. If someone could let me know how to implement bool isReachable(Vertex src, Vertex target, Graph g); I would really appreciate it. Or if you have a better algorithm, I'd love to hear it. Thanks, Tom ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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RE: [Boost-Users] Re: Extended use of BGL File Dependency Example
by Tom Matelich 23 Dec '02

23 Dec '02

> From: Tom Matelich [mailto:tmatelich@zetec.com] > Sent: Sunday, December 01, 2002 9:11 PM > > From: David Abrahams [mailto:dave@boost-consulting.com] > > Tom Matelich <tmatelich(a)zetec.com> writes: > > > > > From: David Abrahams [mailto:dave@boost-consulting.com] > > > Sent: Sunday, December 01, 2002 5:58 AM > > >> Tom Matelich <tmatelich(a)zetec.com> writes: > > >> > > >> > trying to make my graphviz representation look nicer and I > > >> was wondering if > > >> > there is an algorithm already for simplifying: > > > > > > -----B\ > > > A--< \ > > > --------C > > > D----------/ > > > > > > to: > > > > > > A---B---C > > > D------/ > > > > > > This eliminated the A-C edge. > > > > > > Thanks for considering my problem. > > > > Maybe you want a minimum spanning tree, where the weight of > > each edge in the tree is determined by the distance between its > > vertices in some topological sort? > > > > That seems to solve the cases shown above pretty nicely. > > I had looked at the minimum spanning tree docs a bit, I > thought it looked pretty good. The docs say undirected graph though. I'm > currently using a directed graph. I suppose I could create a separate graph. > Oh, I see, create an undirected graph with weights as you said, and use > the minimum spanning algorithm to choose the useful edges. I like it, > hope it works. > Well, I finally got back to this and it almost worked. Things look a lot nicer, the only problem is some edges were lost that I would want to keep. I'll give a list of edges rather than try to draw ascii graphs. So I start out with edges: [1,0], [2,0], [3,0], [4,0], [3,1], [4,2], [4,3] Ideally I want this reduced to: [1,0], [2,0], [3,1], [4,2], [4,3] What I'm getting is: [1,0], [3,1], [4,2], [4,3] Of course my graph is bigger and I have a lot more dead ends than just at 2. 0 is a place holder I have for a "Valid System", so every thing should hit that eventually. I implemented this in the following manner: [create typedefs for undirected graph to be minimized] [get the order from the topological sort in a vector] [create the undirected graph with all edges from dependency graph, assigning weight to be the distance between source and target in the topological sort] [create a vector of edges called spanning_tree] [call kruskal_minimum_spanning_tree(undirected_graph, std::back_inserter(spanning_tree)); ] [then I recreated the directed graph out of the edges in spanning_tree, so I could have my arrows in graphviz] I'm going to try using prim_minimum_spanning_tree, I assume I should expect the same results, but I'll see. Thanks for any advice, Tom ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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Error in testing class tuple
by agiatojon <JonAgiato＠nyc.rr.com> 23 Dec '02

23 Dec '02

Happy Holidays to everyone! I am getting aquainted with the tuple class but am encountering the following error: c:\BGL\boost_1_29_0\boost\tuple\tuple_comparison.hpp(119): error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' with [ x=false ] with the following program: /** * tupleTest.cpp * Test of Boost library class tuple * A tuple is a fixed size collection of elements * Stored objects may be of different types * Current support of tuples with 0-10 objects * Objects may be any valid C++ type except void and function types * Jon Agiato * 12-23-02 */ #include <iostream> using std::cout; using std::cin; using std::ostream; using std::cerr; #include <cstdlib> #include <boost/tuple/tuple.hpp> using boost::tuple; // both tuple_io.hpp and tuple_comparison.hpp include tuple.hpp // tuple_io must be included for tuple input and output operators #include <boost/tuple/tuple_io.hpp> // tuple_comparison.hpp must be included for comparison operators #include <boost/tuple/tuple_comparison.hpp> #include <string> using std::string; #include <exception> using std::exception; class A { friend ostream &operator<<(ostream &output, const A &a) { output << a.S; return output; } public: A(string s = "Testing"):S(s) {;} string S; }; class B { friend ostream &operator<<(ostream &output, const B &b) { output << b.D; return output; } public: B(double d = 3.501):D(d) {;} double D; }; class C { friend ostream &operator<<(ostream &output, const C &c) { output << c.state; return output; } public: C(bool st = true):state(st) {;} double state; }; int main() { try { tuple<A, B, C> testTuple; cout << testTuple << '\n'; tuple<B, A> test2Tuple; if(testTuple == test2Tuple) cout << testTuple << " is equal to " << test2Tuple << '\n'; else cout << testTuple << " is not equal to " << test2Tuple << '\n'; cout << "Press enter to exit..."; cin.get(); return EXIT_SUCCESS; } catch(const exception &E) { cerr << "Standard library exception: " << E.what() << '\n'; return EXIT_FAILURE; } catch(...) { cerr << "Unknown exception thrown.\n"; return EXIT_FAILURE; } } I am using Visual Studio.NET Enterprise Architect Thanks! Jon Agiato JonAgiato(a)nyc.rr.com

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Newbie: customizing dfs
by Gil Shallom 23 Dec '02

23 Dec '02

Hi, Sorry if I missed anything in any FAQ. I would like to customize dfs so it would go over an edge only if satisfies certain properties. The library allows to take actions using visitors, but I haven't found a nice way to modify its decision so it would scan only part of the tree according to certain properties. I can change depth_first_visit_impl in depth_first_search.hpp or maybe define a new algorithm in a new namespace, but all I actualy want is something like my visitor returning false/true thus telling the algorithm whether to continue scanning an edge or not. Does anyone think of a nice way to do this? Or have I missed a feature already implemented in BGL? Any help would be appreciated, Thanks, Gil Shallom

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boost::python : project outside boost tree
by Juerg Tschirren 22 Dec '02

22 Dec '02

I have trouble getting a boost::python project to compile outside the boost directory tree. I can compile the "hello, world" example in {boost}/libs/python/example/tutorial witout problem. But now I would like to start my own project outside the boost tree. To start with I copied the above "tutorial" directory into my home-directory and modified the Jamfile to: #--- begin Jamfile # Include definitions needed for Python modules SEARCH on python.jam = $(BOOST_BUILD_PATH) ; include python.jam ; extension hello : hello.cpp <dll>$(BOOST_ROOT)/libs/python/build/boost_python : <sysinclude>$(BOOST_ROOT) ; #---- end Jamfile I set export PYTHON_ROOT=/usr export PYTHON_VERSION=2.2 export BOOST_BUILD_PATH=/usr/lib/boost_1_29_0 export BOOST_ROOT=/usr/lib/boost_1_29_0 (boost is in /usr/lib/boost_1_29_0 and Python 2.2.1 is in /usr/lib/python2.2 and /usr/include/python2.2) When I now call bjam I get the messages: ../../../Jamrules: No such file or directory /usr/lib/boost/tools/build/boost-base.jam:1455: in find-compatible-subvariant *** argument error * rule is-link-compatible ( feature : value1 : value2 ) * called with: ( <target-type> : PYD : ) * missing argument value2 /usr/lib/boost/tools/build/boost-base.jam:1416:see definition of rule 'is-link-compatible' being called /usr/lib/boost/tools/build/boost-base.jam:1502: in link-libraries /usr/lib/boost/tools/build/boost-base.jam:1712: in subvariant-target /usr/lib/boost/tools/build/boost-base.jam:1797: in main-target /usr/lib/boost/tools/build/boost-base.jam:1330: in declare-local-target /usr/lib/boost/tools/build/python.jam:302: in extension Jamfile:29: in load-jamfiles /usr/lib/boost/tools/build/bootstrap.jam:15: in boost-build /usr/lib/boost/boost-build.jam:2: in module scope I suspect something is wrong with my Jamfile, but what? Any help would be greatly appreciated. Juerg

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[BGL] Possible bug in minimum_degree_ordering
by Jeppe N. Madsen 22 Dec '02

22 Dec '02

Hi, I'm fairly new to BGL so this may not be a bug after all......but I get a fair number of warnings about possible loss of data due to conversions (mainly between signed/unsigned types) with MSVC7 trying to compile the example below. Some may be ignored but at least line 188 of minimum_degree_ordering.hpp seems wrong: data[id[i]] = - (id[j] + offset); id[j] is unsigned, making (id[j] + offset) unsigned thus making the unary minus rather spurious. Also, compile time checks for correctly using signed types for the permutations would be nice :-) rgds Jeppe #include <iostream> #include <boost/graph/adjacency_list.hpp> #include "boost/graph/minimum_degree_ordering.hpp" #include <iostream> #include <boost/graph/adjacency_list.hpp> #include "boost/graph/minimum_degree_ordering.hpp" using namespace std; using namespace boost; int main(int, char **) { typedef adjacency_list <vecS, vecS, directedS> Graph; Graph G; add_edge(0, 1, G); add_edge(1, 0, G); add_edge(0, 2, G); add_edge(2, 0, G); add_edge(0, 5, G); add_edge(5, 0, G); add_edge(1, 2, G); add_edge(2, 1, G); add_edge(1, 3, G); add_edge(3, 1, G); add_edge(1, 6, G); add_edge(6, 1, G); add_edge(2, 4, G); add_edge(4, 2, G); add_edge(3, 4, G); add_edge(4, 3, G); add_edge(4, 5, G); add_edge(5, 4, G); std::vector<size_t> degree(num_vertices(G), 0); std::vector<int> inverse_perm(num_vertices(G), 0), perm(num_vertices(G), 0); std::vector<size_t> supernode_sizes(num_vertices(G), 1); property_map<Graph, vertex_index_t>::type id = get(vertex_index, G); minimum_degree_ordering (G, make_iterator_property_map(&degree[0], id, degree[0]), &inverse_perm[0], &perm[0], make_iterator_property_map(&supernode_sizes[0], id, supernode_sizes[0]), 0, id); for(size_t i = 0; i < num_vertices(G); ++i) std::cout << inverse_perm[i] << "\n"; return 0; }

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boost::python abstract base class
by John Hunter 20 Dec '02

20 Dec '02

I am trying to get raw pointers and abstract base classes working properly with boost::python v2. I am working on an example inspired by the tutorial http://www.boost.org/libs/python/doc/tutorial/doc/inheritance.html. In my case, the base class has a pure virtual function, but I don't need to override it in python and call it from c++, so I don't think I need to do a BaseWrap. The problem is that if I try and expose Base to python, I get the compiler (gcc 3.2) error: g++ -isystem/usr/local/include -I/usr/local/include/python2.2 -fPIC -ftemplate-depth-100 -c rawpointer.cpp /usr/local/include/boost/python/object/value_holder.hpp: In instantiation of `boost::python::objects::value_holder<Base>': /usr/local/include/boost/type_traits/alignment_of.hpp:52: instantiated from `boost::detail::alignment_of_impl<boost::python::objects::value_holder<Base> >' /usr/local/include/boost/python/object/instance.hpp:29: instantiated from `boost::alignment_of<boost::python::objects::value_holder<Base> >' ...snip... rawpointer.cpp:47: instantiated from here /usr/local/include/boost/python/object/value_holder.hpp:36: cannot declare field `boost::python::objects::value_holder<Base>::m_held' to be of type ` Base' /usr/local/include/boost/python/object/value_holder.hpp:36: because the following virtual functions are abstract: rawpointer.cpp:15: virtual const std::string& Base::get_name() rawpointer.cpp:14: virtual void Base::sayit() const make: *** [rawpointer.o] Error 1 and if I only expose the derived classes, the code compiles but then I get a runtime error when I try and import the class in python >>> import rawpointer Traceback (most recent call last): File "<stdin>", line 1, in ? RuntimeError: extension class wrapper for base class 4Base has not been created yet >>> Below is my example code. Suggestions welcomed! John Hunter // work with raw pointers #include <iostream> #include <string> #include <boost/python.hpp> #include <boost/python/manage_new_object.hpp> using namespace boost::python; class Base { public: virtual ~Base() {}; virtual void sayit() const=0; virtual const std::string& get_name()=0; private: }; class Foo : public Base { public: Foo() : _name("Foo") {} void sayit() const { std::cout << "Foo" << std::endl; } const std::string& get_name() {return _name;} private: const std::string _name; }; class Bar : public Base { public: Bar() : _name("Bar") {} void sayit() const { std::cout << "Bar" << std::endl; } const std::string& get_name() {return _name;} private: const std::string _name; }; Base* barfactory(){ return new Bar(); } Base* foofactory(){ return new Foo(); } std::string simonsays(Base* p) {return p->get_name();} BOOST_PYTHON_MODULE_INIT(rawpointer) { class_<Base>("Base", no_init) .def("sayit", &Base::sayit); class_<Foo, bases<Base> >("Foo") .def("sayit", &Foo::sayit); class_<Bar, bases<Base> >("Bar") .def("sayit", &Bar::sayit); def("foofactory", foofactory, return_value_policy<manage_new_object>()); def("barfactory", barfactory, return_value_policy<manage_new_object>()); def("simonsays", simonsays); }

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Why file_system build on msvc 6.5 is only dynamic?
by Daniel Yerushalmi 20 Dec '02

20 Dec '02

Hi All I got filesyetm from the CVS and build it using bjam (no args with VCVARS32.BAT of msvc 6.5) Only the folder: runtime-link-dynamic was created under bin/lisbfs.lib/msvc. Other libraies (i.e. thread) build by default also runtime-link-static. What should I do to do the build with static run time library? Thanks Daniel

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Re: [Boost-Users] Re: Re: Preprocessor library question
by Tanton Gibbs 20 Dec '02

20 Dec '02

> Are all the record lengths constant at any given time? > > Paul Mensonides Yes, for any given invocation of the program the record lengths and the record field lengths are constant. It is only with different invocations of the program that the record lengths or field lengths can change.

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Re: [Boost-Users] Re: Preprocessor library question
by Tanton Gibbs 20 Dec '02

20 Dec '02

Thanks for your response, I'll look through it and try to get a full grasp on everything you said. Basically, my problem is this I have to read in a file of fixed length records, manipulate them (e.g., sort, dedup, group, some custom processing ) and then write them out. There are about 40M records, so I want it to be as fast as possible. If I know the length of the record fields ahead of time, it is MUCH more efficient. However, I would like the field lengths to be customizable at runtime...I thought if I could precompute the program for various values of the 3 fields, then I could have the best of both worlds. However, I forgot about all the template instantiations...perhaps they'll just have to recompile when they want a new field length. Tanton ----- Original Message ----- From: "Paul Mensonides" <yg-boost-users(a)m.gmane.org> To: <boost-users(a)yahoogroups.com> Sent: Thursday, December 19, 2002 1:56 AM Subject: [Boost-Users] Re: Preprocessor library question > > "Tanton Gibbs" <thgibbs(a)deltafarms.com> wrote in message > news:024e01c2a725$6814d720$b048cc18@Corp.Acxiom.net... > > I'm trying to create a template class based on user input. For example: > > > > template< int i, int j, int k > class T {}; > > > > int main() { > > int i, j, k; > > cin >> i >> j >> k; > > T<i, j, k> t; > > } > > > > Naturally, this is not possible, as i, j, and k must be constants. > Therefore, I would like to limit the maximum value of i, j, and k to 100 and > create all permutations for T<i,,j,k> at compile time. Basically, something > like this: > > Hi Tanton, > > You realize that this will give you a 101*101*101 permutation right? While > the pp-lib can generate it, that is a pretty big block of code to be inside > a single function. I would try to separate it into separate functions if > possible: > > template<int i, int j, int k> struct bound { > static void target() { > T<i, j, k> t; > // ... > } > }; > > typedef void (* pf)(); > > template<int i, int j> pf bind(int k) { > switch (k) { > case 0: > return &bound<i, j, 0>::target; > break; > case 1: > return &bound<i, j, 1>::target; > break; > > // ... > > default: > return 0; > } > } > > template<int i> pf bind(int j, int k) { > switch (j) { > case 0: > return bind<i, 0>(k); > case 1: > return bind<i, 1>(k); > > // ... > > default: > return 0; > } > } > > pf bind(int i, int j, int k) { > switch (i) { > case 0: > return bind<0>(j, k); > case 1: > return bind<1>(j, k); > > // ... > > default: > return 0; > } > } > > int main() { > int i, j, k; > std::cin >> i >> j >> k; > bind(i, j, k)(); > // ... > } > > Will something like that work for you? Something similar to this is *way* > better than having an if structure with 101*101*101 conditional tests. If > so, here is an implementation: > > #include <iostream> > #include <boost/preprocessor/iteration/local.hpp> > > #define LIMIT 100 > > template<int i, int j, int k> struct bound { > static void target() { > std::cout << i << ' ' << j << ' ' << k << &std::endl; > return; > } > }; > > void overflow() { > std::cout << "overflow" << &std::endl; > return; > } > > typedef void (* pbound_f)(); > > template<int i, int j> pbound_f bind(int k) { > switch (k) { > #define BOOST_PP_LOCAL_MACRO(k) \ > case k: \ > return &bound<i, j, k>::target; \ > /**/ > #define BOOST_PP_LOCAL_LIMITS (0, LIMIT) > #include BOOST_PP_LOCAL_ITERATE() > default: > return &overflow; > } > } > > template<int i> pbound_f bind(int j, int k) { > switch (j) { > #define BOOST_PP_LOCAL_MACRO(j) \ > case j: \ > return bind<i, j>(k); \ > /**/ > #define BOOST_PP_LOCAL_LIMITS (0, LIMIT) > #include BOOST_PP_LOCAL_ITERATE() > default: > return &overflow; > } > } > > pbound_f bind(int i, int j, int k) { > switch (i) { > #define BOOST_PP_LOCAL_MACRO(i) \ > case i: \ > return bind<i>(j, k); \ > /**/ > #define BOOST_PP_LOCAL_LIMITS (0, LIMIT) > #include BOOST_PP_LOCAL_ITERATE() > default: > return &overflow; > } > } > > int main() { > int i, j, k; > std::cin >> i >> j >> k; > bind(i, j, k)(); > return 0; > } > > This works, but takes forever to compile--at least on Comeau C++. The > reason is not the use of the pp-lib though (that is fast), it is because of > the sheer amount of template instantiations. E.g. you get 101 > instantiations of the one-template-argument "bind," 10,201 instantiations of > the two-template-argument "bind," and 1,030,301 instantiations of the > "target" function (+ 1,030,301 instantiations of "T"). Even if you use the > "if/else if" statements (or nested switches), you still going to get > instantiations of "T" in the millions. That means that you have to 1) bite > the bullet and give up trying to do whatever you're doing with compile-time > values or 2) seriously reduce the maximum value (to about 10, for example). > In any case, the pp-lib can generate this, direct nested switches, or even > the permutations along the lines of "if/else if." The problem is massive > instantiation and massive code bloat no matter how you do it. IMHO, it just > isn't worth it. > > Another idea is to have an array of function pointers: > > pbound_f array[101][101][101] = { ... }; > > ...and initialize the elements with instantiations of some fully bound > function template (the pp-lib can, of course, do this as well). And use it > like this: > > array[i][j][k](); > > This will only avoid the first 10,302 instantiations though. You are still > going to get template instantiation in the millions. What are you trying to > do exactly? Maybe there is a better way. > > > Naturally, I don't want to type all that in myself, so I was hoping the > boost preprocessor library could do it for me. If someone knows of a way to > do it, please let me know. > > Regards, > Paul Mensonides > > > > > > > > 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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Using Boost.Build for non Boost projects?
by Felix E. Klee 19 Dec '02

19 Dec '02

Hi, from the Boost.Build documentation it is not clear to me whether Boost.Build is a system specifically designed for building Boost libraries or whether it is a general purpose build system. For example in the "Getting Started" section there are examples for setting up an independent project whereas in the "Design Criteria" section it is shown that Boost.Build was specifically designed for building Boost libraries. Now I wonder whether it is wise to use Boost.Build for non Boost projects or whether I should set up my own build system based on the original Perforce Jam (eg. because Boost.Build might become tightly integrated with Boost in the future). Felix

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Build boost with vc7 toolset failed.
by Black Ice 19 Dec '02

19 Dec '02

vc 7 boost 1.29.0 set BOOST_ROOT=D:\boost\boost_1_29_0 set VISUALC="C:\Program Files\Microsoft Visual Studio .NET\Vc7" bjam "-sTOOLS=vc7" Command line error D2016 : '/Za' and '/Ze' command-line options are incompatible Any suggestion are appreciated.

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Another threads question...
by Martin Johnson 19 Dec '02

19 Dec '02

Hi, Just to get it through my thick skull. >The threadmon.dll is a seperate library that's always dynamically linked. Then why not make threads a dynamic lib. As an exercise I attempted this though as I found that the template methods of condition a little troublesome. Could this not be reworked by reworking or typing the condition class. I am able to build the lib as a dll with threadmon.cpp included. It involves exporting all classes and crude hack to condition *just* to get it to work. It would appear to function correctly as far as I can see. With the cleanup handlers being called without requiring a seperate dll, though I guess this puts a static link a little out of the picture. But why would I static link anyway, for distribution purposes, but I have to distribute threadmon.dll What do you think? I am just trying to think of a way around it, I know you have been there done that but i just need to appreciate this a little better. Regards Martin Johnson

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MacOS X MSL Mach-O Problem with Threads
by Bobby Thomale 19 Dec '02

19 Dec '02

It's me again with weird problems compiling Boost on the Mac! :-) I just converted my MacOS X code from CFM to Mach-O and I ran into another small compilation problem. This time, it is the thread code. Now that I am moved over to Mach-O, the _POSIX_THREADS flag is true, causing posix_features.hpp to set BOOST_HAS_PTHREADS to true. This seems to be causing all sorts of compiler errors. Probably due to the fact that, even though some of the posix headers are being included, I am using the MSL headers rather than the BSD headers, and my understanding is that none of that posix stuff will actually work until I eject the MSL in favor of the Unix C headers, which I am not prepared to do right now. That and the fact that since I am using Carbon, TARGET_CARBON is also true, therefore BOOST_HAS_MPTASKS is getting set to true. So anyway ... BOOST_HAS_PTHREADS and BOOST_HAS_MPTASKS are both getting defined. I would like to be able to control whether BOOST_HAS_PTHREADS gets defined, because I am actually wanting to use the MP libraries instead, despite _POSIX_THREADS being defined. It looks like how you handled this same problem with Windows was by adding a !defined(BOOST_HAS_WINTHREADS) to the condition as follows: # if defined(_POSIX_THREADS) && (_POSIX_THREADS+0 >= 0) && !defined(BOOST_HAS_WINTHREADS) # define BOOST_HAS_PTHREADS # endif One solution would be to add an additional check for MP Tasks as follows: # if defined(_POSIX_THREADS) && (_POSIX_THREADS+0 >= 0) && !defined(BOOST_HAS_WINTHREADS) && !defined(BOOST_HAS_MPTASKS) # define BOOST_HAS_PTHREADS # endif I did this in my local working copy and it seems to have fixed the problem. I had to add an additional "#define BOOST_HAS_MPTASKS" to my user.hpp to make sure that BOOST_HAS_MPTASKS got defined before the above check. I am not sure if this is the best way or if there is a better way to solve this problem. I suppose another approach would be to check for !defined(TARGET_CARBON) in the above check - if carbon is on, MP Tasks will get turned on. Or you could in the place where BOOST_HAS_MPTASKS gets defined, undef the BOOST_HAS_PTHREADS. But the way I solved it in my local copy (shown above) using !defined(BOOST_HAS_MPTASKS) seemed the cleanest to me, especially since it looks like it is how you solved the same problem for Windows. Anyway - I tried hard to find a way to make this compile without changing anything but my user.hpp but I failed. (If someone has any ideas I'd love to hear them.) -- Bobby --------------------------------------------------------------------- Bobby Thomale Senior Software Developer Inoveon Corporation http://www.inoveon.com/ ---------------------------------------------------------------------

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compilation error with boost_1.29.0
by Volker Boerchers 19 Dec '02

19 Dec '02

Hi, I'm getting the following error on Linux 2.2.16 / Suse 7.0 / g++ 2.95.2 / glibc 2.1.3: ../../../../../include/boost/pool/detail/ct_gcd_lcm.hpp:43: sorry, not implemented: `static_cast_expr' not supported by dump_expr ../../../../../include/boost/pool/detail/ct_gcd_lcm.hpp:43: sorry, not implemented: `static_cast_expr' not supported by dump_expr The following patch fixes it: --- include/boost/pool/detail/ct_gcd_lcm.hpp.orig Thu Dec 19 15:10:54 2002 +++ include/boost/pool/detail/ct_gcd_lcm.hpp Thu Dec 19 14:58:41 2002 @@ -38,7 +38,7 @@ BOOST_STATIC_CONSTANT(unsigned, A_mod_B_ = A % B); BOOST_STATIC_CONSTANT(unsigned, value = (::boost::details::pool::details::ct_gcd_helper< - B, static_cast<unsigned>(A_mod_B_), + B, A_mod_B_, ::boost::type_traits::ice_eq<A_mod_B_, 0>::value >::value) ); }; What is the cast good for anyway? It seems redundant. Regards, Volker -- Volker Boerchers <vboerchers(a)tecon.de> System Engineer TECON Systems AG, Perlengraben 2, 50676 Köln, http://www.tecon.de Tel: +49-221-92007-55, Fax: +49-221-92007-77

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Preprocessor library question
by Tanton Gibbs 19 Dec '02

19 Dec '02

I'm trying to create a template class based on user input. For example: template< int i, int j, int k > class T {}; int main() { int i, j, k; cin >> i >> j >> k; T<i, j, k> t; } Naturally, this is not possible, as i, j, and k must be constants. Therefore, I would like to limit the maximum value of i, j, and k to 100 and create all permutations for T<i,,j,k> at compile time. Basically, something like this: int main() { int i, j, k; cin >> i >> j >> k; if( i == 0 && j == 0 && k == 0 ) { T<0,0,0> t; } else if( i == 0 && j == 0 && k == 1 ) { T<0,0,1> t; } ... else if( i == 100 && j == 100 && k == 100 ) { T<100,100,100> t; } } Naturally, I don't want to type all that in myself, so I was hoping the boost preprocessor library could do it for me. If someone knows of a way to do it, please let me know. Thanks! Tanton [Non-text portions of this message have been removed]

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Matrix-Matrix reference
by Wilken, Marc 18 Dec '02

18 Dec '02

Hello, does ublas support a matrix method like blitz++ .reference() method? (This method allows different matrices to share the same matrix datas.) Marc Wilken This e-mail contains confidential information for the exclusive attention of the intended addressee. Any access of third parties to this e-mail is unauthorised. Any use of this e-mail by unintended recipients such as copying, distribution, disclosure etc. is prohibited and may be unlawful. When addressed to our clients the content of this e-mail is subject to the General Terms and Conditions of GL's Group of Companies applicable at the date of this e-mail. GL's Group of Companies does not warrant and/or guarantee that this message at the moment of receipt is authentic, correct and its communication free of errors, interruption etc.

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Problem with "this" and shared_ptr
by Michael Brinkmann 18 Dec '02

18 Dec '02

Hello, given the following code which uses shared_ptrs, I'm getting a double-free onto an object of type A: ------------------------------------------------------ #include <boost/shared_ptr.hpp> #include <list> #include <iostream> class A { public: A(void){} void makeSomething(void); void makeSomethingOther(void) { std::cout << "A" << std::endl; } }; typedef boost::shared_ptr<A> APtr; class B { public: B(const APtr& a) : mA(a) {} void makeSomething(void) { std::cout << "B" << std::endl; mA->makeSomethingOther(); } private: APtr mA; }; void A::makeSomething(void) { B b(this); // here I want to hand over the "A" shared pointer to "B", but I have only my "this" at hand. std::cout << "A" << std::endl; b.makeSomething(); } int main(void) { APtr a(new A); a->makeSomething(); } ------------------------------------------------------ (please don't ask me about why I'm doing it in that way, the code is stripped down from a much bigger program) I understand that the problem results from the accesss to "this" in the commented line. Is there an elegant way to get the shared_ptr pointing to "this" from "this", which would be the solution to the fault? Or do I have to store a shared_ptr member variable referencing "this" in the class A which is set by a A::method from outside of A to reference it? (not very beautiful) Sorry if this is a FAQ, but I didn't find a solution on news.gmane.org kind regards Michael

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Re: [Boost-Users] Re: Thread library: get thread id
by dick.bridges＠tais.com 18 Dec '02

18 Dec '02

<alternative exemplar> When I implemented the Leader-Follower thread pattern described by Schmidt, et al in Pattern-Oriented Software Architecture, I couldn't figure out a way around comparing the thread id to the current leader in the promote_new_leader function. Probably lack of imagination and/or experience on my part, but having the thread id sure made it easier. </alternative exemplar> "William E. Kempf" To: <Boost-Users(a)yahoogroups.com> <wekempf(a)cox.net cc: > Subject: Re: [Boost-Users] Re: Thread library: get thread id 12/16/2002 01:20 PM Please respond to Boost-Users olivier_debels said: > --- In Boost-Users(a)yahoogroups.com, "William E. Kempf" <wekempf@c...> > wrote: >> >> olivier_debels said: >> > >> > I'm using boost_1_29_0 and need to get the id of the current > thread. >> >> Why? >> > I have several threads which pop messages from the queue. I want to > keep track of what each thread pops (depending on some rules) without > adding an extra parameter (threadId) in the pop-function. I don't follow this. > By this way threads just call the pop-function (they don't know > anything about the internal cooking of the queue). They get a > message, which fulfills the rules (one of the rules is f.e. that no > two threads can handle the same message at the same time). How does a thread id figure into this? What little of this description I understand gives no need for a thread id. William E. Kempf 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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switching to BGL
by Daniel Varga 18 Dec '02

18 Dec '02

Hi, I'm planning to throw away my own little undirected graph implementation in favor of Boost Graphs. My implementation is based on an STL map< Node,set<Node> > adjecency map. I see that it's very easy to get the same functionality using the BGL adjecency_list. But what I really like about my implementation is that I have const set<Node>& Graph::lookupNeighbours(const Node&) const; This means that in no time I can get a _container_ of the neighbours, and not just a pair of iterators. Of course teoretically they are equivalent. But I want to rewrite as little code as possible, so I would like to wrap my old graph interface around the Boost Graph. (Not hiding its own, better interface, of course. :) ) Should I write a wrapper container class simulating const set<Node>? Or does adjecency_list expose the very same const set<Node>& for me?

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Threads question
by Martin Johnson 18 Dec '02

18 Dec '02

Hi, This has probably been asked before. I cant find doco giving detail. So excuse me if this is old topic. I am involved with GPL project that uses boost::threads. I have a problem understanding implementation and what threadmon.dll is for. I see that the code is attempting to manage tss stuff. How is the tss stuff managed when lib is a static link under win32? Is it correct that if I wish to static link that I need this other threadmon.dll as well. Has it been suggested that structured exceptions can perform the same function on win32 with a finally() handler from within thread_proxy? This is a gurantee of invocation. The cleanup attempt could though win32 doco states cleanup is guranteed, though couldnt a lib global could easily handle main thread cleanup? Regards Martin Johnson

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Thread library: get thread id
by olivier_debels <olivier_debels＠yahoo.com> 17 Dec '02

17 Dec '02

I'm using boost_1_29_0 and need to get the id of the current thread. Is there a way to get the id of the current thread using boost? I don't see how I can access the current thread (Is there some sort of current function?). If I could access the current thread, I could write a getId() function (in a class subclassed from boost::thread). Only problem there is the return type. It seems the id is an int in windows environment, a pthread_t in POSIX and a MPTaskID in MACOS. Those last two seems to be pointers to struct. I guess it is possible to cast all of them to long (using reinterpret casting), but maybe I am overlooking something then. thanks, Olivier.

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Issues on getting the reference of the held value of boost::any
by Seishi Onishi <looper2k＠yahoo.com> 17 Dec '02

17 Dec '02

I'm using a collection of boost::any for the variable container class which has this map member. std::map<std::string, boost::any> m_collection; As you imagine, the container class can keep anything even the container class itself recursively. You know, an boost::any may hold copy expensive object. So I need a method to get the reference of the value held in boost::any not to make the expensive copy. But I found that the current any_cast implementation was not well support the reference. Issue 1: The following code causes compiler error on VC6&7. boost::any dany = double(1.2); double& rd = boost::any_cast<double>(dany); Issue 2: The following code works but one copy constructer called. class Foo foo; boost::any fany( foo ); class Foo& rfoo = boost::any_cast<class Foo>(fany); Actually, I found the way to sneak out of the issues. double& rd = *boost::any_cast<double>(&dany); class Foo& rfoo = *boost::any_cast<class Foo>(&fany); But the problem is these codes won't throw bad_any_cast. And I also wonder this *any_cast usage may not be the way the developer supposed. So I expect that the current any_cast code will be changed to well support the reference access. It can be, template<typename ValueType> const ValueType& any_cast(const any & operand) { const ValueType * result = any_cast<ValueType>(&operand); if(!result) throw bad_any_cast(); return *result; } template<typename ValueType> ValueType& any_cast(any & operand) { ValueType * result = any_cast<ValueType>(&operand); if(!result) throw bad_any_cast(); return *result; } -Seishi

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[Boost-Users][BGL] Permutation of a graph
by Paolo Fosser 17 Dec '02

17 Dec '02

Hi all, I'm using BGL in some graph matching algorithms. Now I have to shuffle a bit one of the graphs I'm comparing. I think it all ends up in considering the nodes in a different order when cycling on them. (BTW am I right?). So my question: is there an elegant way to do this in BGL? The only solution that comes into my mind is to build up a map from the range of vertex descriptors to a permutation of them. TIA, Paolo -- Do you want to live forever? Alex Chiu has invented a device which will give you physical immortality. Click here! http://www.alexchiu.com/affiliates/clickthru.cgi?id=pfosser

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testing if shared_ptr has been assigned
by TEA Hartmann, Steven 16 Dec '02

16 Dec '02

I need some help in testing for the condition of whether a shared_ptr has been assigned. In the following example, the "if( b != NULL ) does not work. How would I do this test? typedef boost::shared_ptr<int> IPtr; int i( 0 ); IPtr a( i ); IPtr b; if( some condition ) b = a; if( b != NULL ) { // How should this really be coded? } Best Regards, Steve [Non-text portions of this message have been removed]

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Borland: Cannot generate template specialization
by Felix E. Klee 16 Dec '02

16 Dec '02

Hi, I'm trying to compile C++ code that uses the boost/numeric/ublas matrix library with the Kylix C++ Compiler (BC++ 5.7 for LINUX). However, I get several error messages, among them: Error E2299 boost_1_29_0/boost/numeric/ublas/matrix.hpp 522: Cannot generate template specialization from 'container_reference<C>' in function matrix<complex<double>,row_major,unbounded_array<complex<double> > >::iterator1::iterator1(matrix<complex<double>,row_major,unbounded_array<complex<double> > > &,complex<double> * const &) Any ideas how to work around this problem? Felix

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