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

boost::shared_ptr and stl algorithms
by Bill Eidson 15 Apr '05

15 Apr '05

std::vector< boost::shared_ptr<T> > TVec; I want to write a function object to run std::for_each. to do somework against members of T and accumulate results in functor. My attempts have failed in VC7 with memory errors in my operator() method. struct fo { bool operator()( boost::shared_ptr<T>& t ) { return true; } }; Thanks in advance bille

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BGL and reversing / moving edges
by joshrose 17 Dec '03

17 Dec '03

G'day, I was hoping someone might be able to tell me if they've run into any situations using BGL where they needed to move (or reverse (i.e. flip the source and target)) an edge within a graph implemented as an adjacency_list. I'm working on an implementation of an algorithm for max. weight bipartite matching ("the assignment problem"), and one of the assumptions in the algorithm is that non-matched edges are directed from one subgraph, A, to the other subgraph, B, and matched edges are directed the other way. Over the course of growing the matching, a simple way to add and remove edges from the candidate set is just to reverse the edge, thus the need for some way to reverse the edge within BGL. I don't think I can just remove and then re-add the edge in the other direction, primarily because doing so will (I believe) invalidate any edge_descriptors referring to that edge. In particular, there are property maps keeping track of the weight of edges, the predecessors of certain nodes, etc. that use edge descriptors as keys. I've spent a fair bit of time reading the documentation and looking through the implementation of adjacency_lists (incl. edge_list_impl), and I'm not really sure of a way to either move an edge directly within a graph, or even to create a new edge from another s.t. they have the same edge_descriptor (in general a bad thing, probably). Anyone have any thoughts on this? Thanks, -Josh

4 10

bjam and windows command line problem.
by Fernando Cacciola 07 May '03

07 May '03

Hi, I'm having a hard time trying to use bjam to build boost 1.29.0. I have Win98 in Spanish, and I use Borland C++ Builder 5.0 (its bcc32.exe corresponds to is BCC5.5.1) I have boost 1.29.0 installed at: "C:\Libraries\boost\Repository\boost" I've downloaded bjam for Microsoft Windows: >bjam -v Boost.Jam Version 3.1.0. OS=NT. Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc. Copyright 2001 David Turner. Copyright 2001-2002 David Abrahams. I've temporarily modified the root 'jamfile' so that it builds only the Test library. and I've done: subst d: "c:\archivos de programa\borland\cbuilder5" set BCCROOT=d: (you'll see why in a moment) If I try: c:\>cd C:\Libraries\boost\Repository\boost" C:\Libraries\boost\Repository\boost> bjam -sTOOLS=borland I receive messages of the form: borland-C++-action libs\test\build\bin\libpem.lib\borland\debug\runtime-link-static\threading-s ingle\execution_monitor.obj "d:\bin\bcc32" -j5 -q -c -P -w -Ve -Vx -a8 -v -Od -vi- -tWC -WM- -w-8001 -I"libs\test\build" -I"C:\Libraries\boost\Repository\boost" -I"d:\includ e" -o"libs\test\build\bin\libpem.lib\borland\debug\runtime-link-static\thre ading-single\execution_moni Error E2266: No file names given tor.obj" "libs\test\build\../src\execution_monitor.cpp" C:\WINDOWS\TEMP\JAMTMP00.BAT [2] Unknown command "TOR.OBJ" "LIBS\TEST\BUILD\.." "d:\bin\bcc32" -j5 -q -c -P -w -Ve -Vx -a8 -v -Od -vi- -tWC -WM- -w-8001 -I"libs\test\build" -I"C:\Libraries\boost\Repository\boost" -I"d:\includ e" -o"libs\test\build\bin\libpem.lib\borland\debug\runtime-link-static\thre ading-single\execution_monitor.obj" "libs\test\build\../src\execution_monitor.cpp" ...failed borland-C++-action libs\test\build\bin\libpem.lib\borland\debug\runtime-link-static\threading-s ingle\execution_monitor.obj... If I'm interpreting this output correctly, the problem is that the command line feed to bcc32 exceeds 256 characters. What can be done about this? Is there a way for 'borland-tools.jam' to put the bcc32 parameters in a tmp response file and use: bcc32.exe @tmprsp.rsp? Any help will be appreciated. TIA, -- Fernando Cacciola

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boost/type_traits/config.hpp
by H. Morishima 26 Mar '03

26 Mar '03

My compiler issues the following warning message (boost v1.29.0, G++ 3.2 with warning level high): boost_1_29_0/boost/type_traits/config.hpp:90:55: warning: "BOOST_MSVC" is not defined boost/type_traits/config.hpp: line 90 is: # if (........ || BOOST_MSVC > 1301 || ........) Shouldn't it be as follows? # if (........ || #defined(BOOST_MSVC) && BOOST_MSVC > 1301 || ........) H. Morishima

4 5

adjacency_matrix
by agiatojon 12 Mar '03

12 Mar '03

Hello all, I'm new to the list and to Boost in general and am trying to use an adjacency_matrix in order to plot coordinates (hopefully that is a good use for it). I just started trying to learn it and have entered the sample program from page 237 into my compiler (VS.NET) Below is the program I have entered. I am getting errors in that print_vertices, print_edges, and print_graph are undefined and are not members of boost. Any help apprechiated! Thanks. /** * adjaMatri.cpp * Nov 7th, 2002 * Boost Graph Library, pg. 237 */ #include <iostream> using std::cout; using std::cin; using std::endl; #include <boost/graph/adjacency_matrix.hpp> using namespace boost; int main() { enum { A, B, C, D, E, F, N }; const char *name = "ABCDEF"; typedef boost::adjacency_matrix<boost::undirectedS> UGraph; UGraph ug(N); add_edge(B, C, ug); add_edge(B, F, ug); add_edge(C, A, ug); add_edge(D, E, ug); add_edge(F, A, ug); cout << "vertex set: "; boost::print_vertices(ug, name); cout << endl; cout << "edge_set: "; boost::print_edges(ug, name); cout << endl; cout << "incident edges: "; boost::print_graph(ug, name); cout << endl; cout << "Press enter to exit..."; cin.get(); return EXIT_SUCCESS; } Jon Agiato JonAgiato(a)nyc.rr.com

2 1

Re: [Boost-Users] stop a thread
by William E. Kempf 03 Mar '03

03 Mar '03

> From: "hlh771 <hlh771(a)yahoo.com.cn>" <hlh771(a)yahoo.com.cn> > > 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. Today you should use a flag and a condition/mutex combination. Direct support for cancellation is being provided in a future release. William E. Kempf wekempf(a)cox.net

3 4

VC7 says 'fatal C1067' compiling multi_array?
by Clift Norris 01 Mar '03

01 Mar '03

Greetings: I'm using VC7 and boost_1_29_0 to compile this code that is using multi_array.hpp. typedef boost::multi_array<double, 4> theta4_t; typedef theta4_t::index index; theta4_t Theta_Trun( boost::extents[10000][2][10][256] ); I'm receiving this error: "fatal error C1067: compiler limit: debug information module size exceeded" Of course, the code compiles fine using the "Release" configuration, but I need the "Debug" one also. Is there a workaround for this, other than the 'make your variables shorter' suggested in the VC7 documentation? Thanks, -Clift

2 1

Why scoped_ptr dost provide custom deallocation?
by Black Ice 17 Feb '03

17 Feb '03

As following manner: template<class D> scoped_ptr(Y * p, D d); Any suggestion are appreciated. -- /*******************/ ×ÔÓÉ£šliberty£©ÎÞ·ÇŸÍÊÇÕâÑùÒ»ÖÖ³ÐÅµ£ºÃ¿žöÈËœ«»áµÃµœÒ»ÖÖ±£ÕÏ£¬±£ÕÏÎÒÃÇ¿ÉÒÔÓë ÈšÍþ¡¢¶àÊý¡¢Á÷Ë×Œ°ÓßÂÛµÄÓ°ÏìÏà¿¹ºâ¡£ /*******************/

4 7

bug report: boost::tokenizer with VC6
by Navi Singh 09 Feb '03

09 Feb '03

The boost release 1.28.0 of the tokenizer library has the following problem: There are 5 examples, namely, simple_example_1.cpp thru simple_example_5.cpp If I change the main() in each of the 5 to to main1() thru main5() and return 0; the vc60 compiler generates an internal compiler error when parsing the file boost\iterator_adapters.hpp on line 869, where it is parsing the following lines: reference operator*() const { return policies().dereference(*this); }

3 2

[BGL] Using BGL for huge graphs
by Erik Arner 03 Feb '03

03 Feb '03

Hi, has anybody tried using BGL for really huge graphs? I mean graphs that are so big that there's no way to store the whole graph in memory. Any ideas on how it should be implemented? My first thought is that it should be fairly straightforward: simply construct classes that model Sequence or RandomAccessContainer for the VertexList parameter etc. The classes store part of the data in memory and read/write data to disc when necessary. Any pitfalls, gotchas or other stuff I should be aware of before embarking on this? Thanks, /Erik

4 9

Static linkage in VC++
by Amittai Aviram <amittai＠amittai.com> 01 Feb '03

01 Feb '03

I am trying to get my DLL to get linked statically with the boost::regex library and having _no success_. I have tried putting this line into one of the header files: #define BOOST_REGEX_STATIC_LINK And I have tried this line, alone and in combination with the above: #define BOOST_REGEX_NO_LIB I have tried putting the .lib file boost_regex_vc6_mdi.lib into the list of includes under Project->Settings->Link, with or without the above lines. I give up! And of course people want this thing yesterday. Please help? Thanks. Amittai Aviram amittai(a)amittai.com

2 3

Boost and the Lawyers: A Happy Ending (well for us anyway)
by Brian <bneal＠zeus.ia.net> 31 Jan '03

31 Jan '03

Hello again, A while back I posted a series of questions about what other people had done to make their companies lawyers happy about using boost in a commercial project. If you remember, I stated that our lawyers were worried that someone could post someone else's code to boost, passing it of as his own. Our company would then be liable for copyright infringement and other bad things. We thought at the time that we would have to contact each and every boost developer (whose libraries we use) and get them to sign something to say in effect "Yes I wrote this and you have permission to use it". This raised interesting questions like "should there be a standard boost license to make this process less painful"? Well our contracts guy got back to my team of developers. He checked out www.boost.org and did some research on boost. He came to the conclusion that boost was a widely known and used resource, and I guess "trustworthy". All he told us to do was include the boost developers copyright statements on any GUI and to embed said copyright strings into the executable along with ours. Somehow we lucked out. I hope you all have sensible people working for your company too. Thanks, BN And special thanks to the authors of the crc, shared_ptr, regex, and any libraries. You guys ROCK!

1 0

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

1 0

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

3 2

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. -----------------------------------------------------------------------

2 1

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

2 1

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

4 3

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?

1 0

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

4 3

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 :.

3 7

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);

1 0

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

2 2

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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