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Need Digest
by Daryle Walker 05 Dec '01

05 Dec '01

I guess Yahoo Groups had a data burp on 21 Nov 2001, because I didn't get digest 22. Could anyone send it to me? -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT mac DOT com

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OT: Is there a forum for Loki anywhere on the 'net?
by Gooch, Allen 04 Dec '01

04 Dec '01

I know that pieces of Loki are being reviewed for inclusion into Boost, but I was wondering if there is any sort of forum for questions regarding the use of Loki itself, specifically Loki::SmartPtr. Please respond by email to avoid list clutter, unless it relates to boost use. TIA, Allen Gooch

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Re: [Boost-Users] Re: Installing on Windows 95 with Mingw32 1.1
by John Maddock 02 Dec '01

02 Dec '01

>ISTR that when I tried to use boost.threads in the past on Win98, I >encountered problems with the TSS code as well - with MSVC. I didn't see the >page faults since a catch(...) handler on MSVC eats them but the results >were worse than that - the machine locked up in about half of the cases, in >the other half the thread that faulted died without warning. I haven't seen that. >I think that it's possible that the problem is not gcc-specific. Note that >both your successes use pthreads-win32, not the native win32 implementation >of Boost.Threads. the tests run fine using the win32 threads API as well (at least for me), the reason I used pthreads-win32 was to make the tests more directly comparable to cygwin (which has it's own pthreads API). - John Maddock http://ourworld.compuserve.com/homepages/john_maddock/

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graph library compilation on VC++
by zhang3284＠yahoo.com 02 Dec '01

02 Dec '01

I'm new to BGL and studying the examples provided with the library. Here is a problem I'm having: I compiled a program, for example,dfs- example.cpp, it was fine. And then I changed the program a little bit, and tried to recompile it, I got the following error: boost\iterator_adaptors.hpp(845) : fatal error C1001: INTERNAL COMPILER ERROR Then I tried Rebuild All or cleaned the project first, and then compiled it. It became OK again. I'm using VC++ 6.0 SP5. Any comment would be appreciated. Thanks. Yingjun Zhang

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operator<< for boost::any
by Patrick Guio 01 Dec '01

01 Dec '01

Dear all, I am trying to use the any class in a project. I would need to print elements of a vector<any>. I have come to the following solution as an example: template<class T> inline ostream& operator<<(ostream &os, const vector<T> &v) { vector<T>::const_iterator iter(v.begin()); for (int c(0), n(v.size()); c<n-1; c++) os << *iter++ << ','; return os << *iter; } typedef vector<bool> vectb; int main() { vector<any> values; double f(2.0); string s("hello"); int i(100); bool b(false); vectb vectbool; vectbool.push_back(true); vectbool.push_back(false); vectbool.push_back(true); vectbool.push_back(true); vectbool.push_back(false); vectbool.push_back(true); values.push_back(f); values.push_back(s); values.push_back(i); values.push_back(b); values.push_back(vectbool); for (vector<any>::iterator i(values.begin()), last(values.end()); i!=last; i++) { if (any_cast<bool>(i)) cout << *any_cast<bool>(i) << endl; else if (any_cast<int>(i)) cout << *any_cast<int>(i) << endl; else if (any_cast<float>(i)) cout << *any_cast<float>(i) << endl; else if (any_cast<double>(i)) cout << *any_cast<double>(i) << endl; else if (any_cast<string>(i)) cout << *any_cast<string>(i) << endl; else if (any_cast<vectb>(i)) cout << *any_cast<vectb>(i) << endl; } } But I would like a more general solution without to make assumptions about the type. Do you have any ideas? Another point is that I cannot figure out how to convert the solution below in terms of a friend ostream& operator<<(ostream &os, const any &rhs) I cannot get this compiled with g++ v 2.95 friend ostream& operator<<(ostream &os, const any &rhs) { return os << *any_cast<bool>(rhs); } Sincerely, Patrick ====================================================================== Patrick Guio Institute of Physics, University of Oslo P.O. box 1048, Blindern, N-0316 Oslo Tel : (+47) 22 84 40 60 - Fax : (+47) 22 85 56 71 E-mail : patrick.guio(a)fys.uio.no URL : http://folk.uio.no/~patricg

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Re: Installing on Windows 95 with Mingw32 1.1
by John Maddock 01 Dec '01

01 Dec '01

>I got the command line gdb to run, but what a pain. I'm researching >both the GUI version as well as the JIT versions available for >mingw. They may help out. However, the command line version just >stranded me with no clear idea why things were failing, so I don't >know if the other debuggers will be much help. If it helps, I tried debugging the thread code with the latest cygwin GUI debugger (which is almost usable BTW), but still couldn't figure out what the issue was. I also tried with vc6+pthreads-win32 and Borland+pthreads-win32 and both of those check out OK, in the latter case I was able to build both boost.threads and pthreads-win32 with Borlands Codeguard support enabled, and there were no memory related errors, so I think this is something very specific to gcc. BTW I also see a page fault when building with gcc3.01 on Linux - this time the fault goes away if I build in release mode, so I suspect there is an assertion being triggered somewhere, and it's the assertion that's dying. I haven't got any further than that though. - John Maddock http://ourworld.compuserve.com/homepages/john_maddock/

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Installing on Windows 95 with Mingw32 1.1
by karsjens+yahoo＠visionary.com 30 Nov '01

30 Nov '01

Since I had quite a bit of trouble getting started with boost, I though i would document my difficulties so the install process can be improved and other users having similar difficulties might benefit from my experience. I have placed my story on the boost wiki in the topic InstallingOnMingw32Windows95 Direct url: http://www.crystalclearsoftware.com/cgi-bin/boost_ wiki/wiki.pl?InstallingOnMingw32Windows95 I hope this is helpful to somebody. -- Brad Karsjens

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regex and tokenizer, something wrong with namspace ?
by John Maddock 30 Nov '01

30 Nov '01

>I am a new user of the boost library (Actually with VC6 SP5 and stlport 4.0). Everything goes well when I use tokenizer and regexp in separated programs. But when I want to use the regex and the tokenizer library together I can not compile. for example, if I take the $(BOOST_ROOT)/libs/tokenizer/examples.cpp from John R. Bandela and just add the include line: #include <boost/regex.hpp> the compiler gives me this error: < regex and tokeniser appear to use different workarounds for the broken VC6 namespace support, and these seem to conflict, IMO regex is using the correct fix - or at least the one we discussed during the early days of boost, but then I would say that :-) - John Maddock http://ourworld.compuserve.com/homepages/john_maddock/

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warning: unknown rule split
by John Merrells 29 Nov '01

29 Nov '01

I just downloaded boost and the jam.exe on the build page. Executing jam -ftools/build/allyoubase.jam -sTOOLS="msvc" on win2k with msvc 6 I get a screenful of 'warning: unknown rule split'. Anyone experienced this? jam version problem? John [Non-text portions of this message have been removed]

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RE: [Boost-Users] graph library
by Jim.Hyslop 29 Nov '01

29 Nov '01

Ihsan Ali Al Darhi [SMTP:iad929@joinnet.com.jo] wrote: > Can someone of you point me to a good book or URL on graph theory? Ineed > this to understand the BGL. Please. I've found Robert Sedgewick's book "Algorithms in C++" to be quite useful. He has several chapters devoted to graph algorithms. He explains some of the basics, then demonstrates how to implement the algorithms. There are a lot of other algorithms covered as well (string processing, searching and sorting algorithms, geometric algorithms, and so on). -- Jim

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problem compiling boost.function w/ g++ 2.95.3
by Darin Buck 29 Nov '01

29 Nov '01

when trying to compile the following code (cut from the boost.function test suite): #include <boost/bind.hpp> #include <boost/function.hpp> #include <iostream> #include <string> #include <functional> struct X { X(int v) : value(v) {} int twice() const { return 2*value; } int plus(int v) { return value + v; } int value; }; int main() { using namespace boost; boost::function<int, X*> f1(&X::twice); X one(1); cout << "f1(one) = " << f1(&one) << endl; return 0; } _____________________________________________ i get the following errors: /usr/local/include/boost/function/function_template.hpp: In function `static int boost::detail::function::function_obj_invoker1<int (X::*) () const,int,X *>::invoke(boost::detail::function::any_pointer, X *)': /usr/local/include/boost/function/function_template.hpp:689: instantiated from `boost::function1<int,X *,boost::empty_function_policy,boost::empty_function_mixin,allocator >::assign_to<int (X::*)() const>(int (X::* &)() const, boost::detail::function::function_obj_tag)' /usr/local/include/boost/function/function_template.hpp:618: instantiated from `boost::function1<int,X *,boost::empty_function_policy,boost::empty_function_mixin,allocator >::assign_to<int (X::*)() const>(int (X::* &)() const)' /usr/local/include/boost/function/function_template.hpp:463: instantiated from `boost::function1<int,X *,boost::empty_function_policy,boost::empty_function_mixin,allocator >::function1<int (X::*)() const>(int (X::* &)() const)' /usr/local/include/boost/function.hpp:459: instantiated from `boost::function<int,X *,boost::detail::function::unusable,boost::detail::function::unusable, boost::detail::function::unusable,boost::detail::function::unusable,bo ost::detail::function::unusable,boost::detail::function::unusable,boos t::detail::function::unusable,boost::detail::function::unusable,boost: :detail::function::unusable>::function<int (X::*)() const>(int (X::* &)() const)' hello.C:21: instantiated from here /usr/local/include/boost/function/function_template.hpp:272: pointer to member function called, but not in class scope /usr/local/include/boost/function/function_template.hpp:272: warning: control reaches end of non-void function `boost::detail::function::function_obj_invoker1<int (X::*)() const,int,X *>::invoke(boost::detail::function::any_pointer, X *)' /usr/local/include/g++-3/stl_alloc.h: At top level: /usr/local/include/g++-3/stl_alloc.h: In instantiation of `allocator<int (X::*)() const>': /usr/local/include/boost/function/function_base.hpp:131: instantiated from `boost::detail::function::functor_manager<int (X::*) () const,allocator<boost::function_base> >' /usr/local/include/boost/function/function_template.hpp:691: instantiated from `boost::function1<int,X *,boost::empty_function_policy,boost::empty_function_mixin,allocator >::assign_to<int (X::*)() const>(int (X::* &)() const, boost::detail::function::function_obj_tag)' /usr/local/include/boost/function/function_template.hpp:618: instantiated from `boost::function1<int,X *,boost::empty_function_policy,boost::empty_function_mixin,allocator >::assign_to<int (X::*)() const>(int (X::* &)() const)' /usr/local/include/boost/function/function_template.hpp:463: instantiated from `boost::function1<int,X *,boost::empty_function_policy,boost::empty_function_mixin,allocator >::function1<int (X::*)() const>(int (X::* &)() const)' /usr/local/include/boost/function.hpp:459: instantiated from `boost::function<int,X *,boost::detail::function::unusable,boost::detail::function::unusable, boost::detail::function::unusable,boost::detail::function::unusable,bo ost::detail::function::unusable,boost::detail::function::unusable,boos t::detail::function::unusable,boost::detail::function::unusable,boost: :detail::function::unusable>::function<int (X::*)() const>(int (X::* &)() const)' hello.C:21: instantiated from here /usr/local/include/g++-3/stl_alloc.h:750: `allocator<int (X::*)() const>::address(int (X::* &)() const) const' has already been declared in `allocator<int (X::*)() const>' make: *** [hello.o] Error 1 ___________________________________ this code should compile (its just copied from the test code) and my compiler setup should work according to the boost compiler status page. Any ideas what i'm doing wrong? -Darin Buck

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regex and tokenizer, something wrong with namspace ?
by acarsac＠yahoo.fr 28 Nov '01

28 Nov '01

Hi, I am a new user of the boost library (Actually with VC6 SP5 and stlport 4.0). Everything goes well when I use tokenizer and regexp in separated programs. But when I want to use the regex and the tokenizer library together I can not compile. for example, if I take the $(BOOST_ROOT)/libs/tokenizer/examples.cpp from John R. Bandela and just add the include line: #include <boost/regex.hpp> the compiler gives me this error: Compiling... examples.cpp c:\program files\microsoft visual studio\vc98 \include\boost\token_functions.hpp(264) : error C2668: 'ispunct' : ambiguous call to overloaded function c:\program files\microsoft visual studio\vc98 \include\boost\token_functions.hpp(257) : while compiling class- template member function 'bool __thiscall boost::char_delimiters_separator<char,class _STL::char_traits<char> >::is_ret(char) const' Error executing cl.exe. examples.exe - 1 error(s), 0 warning(s) any idees ? Alexandre

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Typelists.
by jamescurran＠mvps.org 28 Nov '01

28 Nov '01

Over on the Boost Developer group, there a lot of talk about how to best implement a typelist. Just so I can follow that discussion, could someone give me the basic thumbnail sketch of what exactly a typelist is, and what they are used for?

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Real-world applications using Boost - results
by Björn Karlsson 27 Nov '01

27 Nov '01

I recently posted a question about "real-world" use of Boost. The (surprisingly few) answers I received can be found at the end of the e-mail. I think it is safe to say that the usage is more widely spread than the answers indicate. [Note: I have excluded the names from the e-mails, although not explicitly asked to do so.] Summary: There were replies from 8 Boosters. It seems that the lightweight utility classes are the most popular, likely due to the fact that their impact on existing systems is easily manageable. Thank you for your answers! Bjorn Karlsson Reply ////////////////////////////////////////////////////////////////////////// Using some small parts of it. Selected because it lets you pick and chose things to use from a large set of (relatively) small components/tools rather than ending up "buying into" some grand scheme of things. Well designed small interfaces rather than including the kitchen sink, making it easier for people to pick up/maintain code later.... Did what I needed to do at the time.... Note that the things I have elected to use so far have been small and intended to reduce the risk of mistakes (eg operators, traits) rather than anything vast. Reply [translated] ////////////////////////////////////////////////////////////////////////// We have just started to use Boost for converting a Python prototype to C++. The experience is still limited, but the results after a few days of work are very good. Reply ////////////////////////////////////////////////////////////////////////// I'm using Boost heavily in FEMTown (www.femtown.org) FEMTown is an open-source finite-element framework in development. We're using Boost because it provides stable and slim functionality that helps us making FEMTown more efficient, flexible and robust. (although our choice of C++ for a scientific application is even kinda controversial) Reply ////////////////////////////////////////////////////////////////////////// At this moment, I'm using the Boost lexical_cast in one of our commercial software products (Pilot - see http://www.leitch.com/custserv/products.nsf/lookup/CCS-PILOT) I needed to convert from integers to text for transmission across the network, then back from text to integer value. I had been using strstream, but the lexical_cast wrapped all the complexity up for me. I chose Boost because it's portable (our software runs on Windows NT and on embedded software using gcc). I knew there is a good chance that lexical_cast will become a standard keyword. As I learn more about the various libraries that are available, I will likely find appropriate places to use them. Reply ////////////////////////////////////////////////////////////////////////// My group is currently using Boost on one project as an experiment. We do cross-platform Macintosh/Windows development and it was valuable to have a tested library that worked on our two main development platforms. We have been phasing different parts of Boost in as come across problems that Boost will solve. As a community I find Boost a source of best practices that I have tried to implement in our workplace. Reply ////////////////////////////////////////////////////////////////////////// We've been using Boost at Zetec for over two years. Initially just for shared_ptr, but since expanding to lexical_cast, iterator_adaptors, tokenizer, and others. If you need any other info, let me know. Reply ////////////////////////////////////////////////////////////////////////// I am starting a new project using boost. It is a financial risk-management engine. I cannot tell you a lot about it yet. We are a team of 8 developers, 4 developing the backend and 4 developing the interfaces. The product will hopefully be a big success in the financial world as it is developed in cooperation with some the best people of the financial industry. It is a 12 months development effort using the XP development process. boost will be used to provide some utility classes (smart pointers, anys, threads ... ). The engine will run on Solaris and Linux. A future version on Windows may exist in the future. Reply ////////////////////////////////////////////////////////////////////////// We've used small parts of Boost in a digital video distribution back-end system; the system was developed by a client of us(us=CMG). If you want names in your summary I'd have to ask for permissions from them.

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(no subject)
by Paul Grenyer 25 Nov '01

25 Nov '01

Paul Grenyer pjgrenyer(a)iee.org

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"referenced symbol not found" when loading modules
by dlrubin＠yahoo.com 25 Nov '01

25 Nov '01

I'm getting a "refernced symbol not found" error when loading modules compiled with Boost. I tried using boost using this example code: #include <stdio.h> #include <string> #include <boost/python/class_builder.hpp> namespace { std::string greet() { return "hello, world"; } int square(int number) { return number * number; } } namespace python = boost::python; BOOST_PYTHON_MODULE_INIT(example) { try { // Create an object representing this extension module. python::module_builder this_module("example"); // Add regular functions to the module. this_module.def(greet, "greet"); } catch(...) { python::handle_exception(); // Deal with the exception for Python } } and when I try importing into python, here's the error I get: Python 2.1.1 (#5, Nov 22 2001, 14:04:45) [GCC 2.95.2 19991024 (release)] on sunos5 Type "copyright", "credits" or "license" for more information. >>> import example Traceback (most recent call last): File "<stdin>", line 1, in ? ImportError: ld.so.1: python: fatal: relocation error: file ./example.so: symbol handle_exception__Q25boost6pythonv: referenced symbol not found Any suggestions? thanks, Daniel

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Introducing Me
by Paul Grenyer 24 Nov '01

24 Nov '01

Dear All I don't know if this is the appropriate thing to do here (I'm sure the moderator will filter me out if it isn't), but I failed to introduce myself on other lists and with hindsight I think it would have been better if I had. I've been programming in C++ for about 18 months, since I left university and started working. I was introduced to the C++ standard library and boost libraries a few months ago by a member of the ACCU. I have just started a new job writing distributed software using the C++ standard library and the ATL and I'm making as much use of boost as possible. Previous to that I was writing windows software to control dot markers and laser markers using the MFC. So, I am very new to boost and am not expecting to be able to contribute much for a while and I'll no doubt need the odd nudge in the right direct. Thanks Paul Paul Grenyer pjgrenyer(a)iee.org

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Re: [boost] how to get a *real* copy of a boost-python object that supports virtual function
by Phil Austin 24 Nov '01

24 Nov '01

(I'm posting to both boost and boost-users, but I'm assuming we're supposed to move this kind of discussion to Boost-Users(a)yahoogroups.com?) dkottowk(a)yahoo.com writes: [snip] > my question is, how do i get a copy of PyGenome_Callback, > which also is a copy of the python-side of the object ? I'd also be interested in a pointer to an elegant way to do this, as well as an example of a from_python function that converts PyObject* to PyGenome_Callback. Brute force does work for me -- i.e. if you need the derived class and can't construct the object in Python code, you can call the derived constructor from the C++ side like this: PyObject* theMod=PyImport_ImportModule("mymodule"); PyObject* theDict=PyModule_GetDict(theMod); py::ref theRef(theDict); py::dictionary modDict(theRef); py::ref constructor=bDict.get_item(py::string("theObject").reference()); PyObject* theInstance=PyObject_CallObject(constructor.get(),0); This was ugly enough so that I added a python wrapper around my extension to construct the derived objects I needed in Python and pass them back to C++. Phil

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boost tokenizer
by pjgrenyer＠iee.org 23 Nov '01

23 Nov '01

Dear All I'm using the boost tokenizer to tokenise lines similar to this one: first_initial |23|1| This gives me: first initial 23 1 but what I actually want is: first_initial 23 1 Does anyone know how to get it to ignore the underscore? Thanks Paul

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passing data to a thread
by d33pmind＠yahoo.fr 23 Nov '01

23 Nov '01

How can I pass data to a thread ? Why does the boost::thread's constructor takes a boost::function0<void> as parameter, instead of a boost::function1<void> which would have allowed to pass it a pointer to a thread safe structure ? Julien.

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core dump when invoking jam
by d33pmind＠yahoo.fr 23 Nov '01

23 Nov '01

On a Linux Mandrake 8.1 (i586), I succesfully built jam, but when I invoke it I got no output except a core dump. Has anyone encountered the same problem ? I compiled it with gcc 3.0.1, and modified gcc-tools.jam to use gcc- 3.0.1 and g++-3.0.1 instead of gcc and g++ (which are 2.96). Thanks. Julien.

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What's safe_bool?
by mr_lilirong＠yahoo.com 23 Nov '01

23 Nov '01

Hi, The following code is excerpted from Boost.Function. I just don't unstanding it. Why use "safe_bool"? What's the advantage? Can any one explain it to me? Thanks. // code from <boost/function/function_base.hpp> // ===> private: struct dummy { void nonnull() {}; }; typedef void (dummy::*safe_bool)(); public: operator safe_bool () const { return (this->empty())? 0 : &dummy::nonnull; } safe_bool operator!() const { return (this->empty())? &dummy::nonnull : 0; } // code from <boost/function/function_base.hpp> // <===

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aCC compilator
by lokys1976＠yahoo.com 22 Nov '01

22 Nov '01

Is it possible using aCC A.03.27 to use boost libraries? When I try to compile using boost examples, it dosn't understand "using namespece std" and so on, when I try to use aCC -AA than it can not find some libraries. Any suggestions how must I use aCC with boost libraries is welcomed very much thank you Paulius

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Threads on MSVC 6.0
by brian_todoroff＠yahoo.com 22 Nov '01

22 Nov '01

I've been trying for a few hours now to get the threads lib examples to compile. I built the libraries with jam and all but python built correctly. When I create a new Win32 console application and copy the code ( See end of message from the thread class example and attempt to compile I get: ===================Start Error --------------------Configuration: threadtest - Win32 Debug----------- --------- Compiling... threadtest.cpp c:\projects\boost\threadtest\threadtest.cpp(27) : error C2228: left of '.join' must have class/struct/union type Error executing cl.exe. Creating browse info file... threadtest.exe - 1 error(s), 0 warning(s) ===================End Error Can't figure out what I'm doing wrong. Thanks for any help. Brian Todoroff ========================Start Code (to end) #include <boost/thread/xtime.hpp> #include <boost/thread/thread.hpp> #include <iostream> struct thread_alarm { thread_alarm(int secs) : m_secs(secs) { } void operator()() { boost::xtime xt; boost::xtime_get(&xt, boost::TIME_UTC); xt.sec += m_secs; boost::thread::sleep(xt); std::cout << "alarm sounded..." << std::endl; } int m_secs; }; int main(int argc, char* argv[]) { int secs = 5; std::cout << "setting alarm for 5 seconds..." << std::endl; boost::thread thrd(thread_alarm(secs)); thrd.join(); // Line 27 - Error here return 0; }

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breadth_first_searchable graph, without invalidable vertex descriptors
by cristipp＠ics.uci.edu 21 Nov '01

21 Nov '01

Hello, I am trying to use the BCG as backbone for a ControlFlowGraph in a compiler project. It seems that I cannot use BCG for this task because of the follow contradicting (from BCG point of view) requirements: 1. I want to be able to breadth_first_search through my graph. 2. I want to be able to keep descriptors to vertices 'for ever' so I can refer a specific vertex at any given time (for removal or whatever other reasons). To implement requirement 1 my adjacency_list should have its VertexList of type vecS. To implement requirement 2 my adjacency_list should have its VertexList of type listS. Unfortunately those are mutualy exclusive and it seems that BCG is unsuited for the job. But I can't really think of a decent generic graph library unable to support those requirements. After all, it's all about being able to use basic graph traversals on randomly mutating graphs. STL has the list which has those nice properties, why a graph library should be different?! Perhaps I am missing something and I am asking for help: how should I declare my graph and how can I do a bfs on it? Thanks in advance, Cristi

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RE: [Boost-Users] question about any class ...
by scleary＠jerviswebb.com 10 Nov '01

10 Nov '01

> any is really a powerful class, but sometimes I would also be > able to know directly the type stored into it without 'guessing', for > example to use it in template code. > What I would like to have is something as > > type_info::real_type for the value hidden into any (not legal > C++, maybe > legal C++0x ?), This actually wouldn't help you, still. How would the declaration look? typeof() wouldn't work, either... > or, alternatively, virtual template functions (again not > legal C++) to be > able to write generic > code depending on both hidden value's type and types 'from the outside > world' (sorry cannot explain it better :-( than this) I have run into this same problem. To re-phrase it, Gianni is trying to do an "operation" on a contained value. 'any' supports the "operations" of copying and destruction as-is; manual modification of 'any' could support other "operations" (this is what Gianni means when he talks about "visiting" the any class, below): any { ... void f() { if (content) content->f(); } }; any::placeholder { ... virtual void f() = 0; }; any::holder<...> ... { ... virtual void f() { held.f(); } }; The problem is how to do this generically (i.e., provide a solution for any "operation"). Another way of looking at this is to force 'any' to call a function that is overloaded on the type of the contained value. Strictly speaking, this isn't possible because 'any' makes the compile-time info into run-time info. > I have tried various approaches, but if I 'visit' the any > class adding a > virtual function to reach hidden value I loose generic type > information > (lack of virtual template functions) from the outside while from the > outside of any > I cannot obtain directly the type of the hidden value ... > > is there a way to do the above ? I have not been successful. Again, 'any' changes compile-time information into run-time information, and to go the other way is just not possible in this language. You could take a "nasty-hack" approach, if you *really* wanted to: 1) Add an 'any_base' class with a virtual function 2) Extend 'any' to return an 'any_base *' referring to the held value, using C-cast notation (derived-to-base when possible, reinterpret when not) 3) Derive your held value types from a common base class 'my_base', which was derived from 'any_base'; add the operations you want to perform to 'my_base' 4) Call the 'any' function returning 'any_base *', downcasting it to 'my_base'. This will result in undefined behaviour if the contained value is not actually derived from 'my_base' (because of the reinterpret_cast behaviour in step 2) I *think* that will work (never tried it). Messy, though, and IMO not generic enough to mess with. Alternatively, you could: 1) Visit 'any'/'any::placeholder'/'any::holder' to provide: void any::action(any which) { content->action(which); } virtual void any::holder::action(any which) { any_action(held, which); } 2) Declare a function 'any_action(T, any)', where the any parameter designates which "operation" to perform. Overloading is then possible on T. Also, where T is a user-defined type, Koenig lookup can be used (abused?) to create different (non-overlapping) sets of "operations". Just some thoughts. Again, I've never tried it. -Steve

2 1

question about any class ...
by Gianni Luciani 10 Nov '01

10 Nov '01

Hi, any is really a powerful class, but sometimes I would also be able to know directly the type stored into it without 'guessing', for example to use it in template code. What I would like to have is something as type_info::real_type for the value hidden into any (not legal C++, maybe legal C++0x ?), or, alternatively, virtual template functions (again not legal C++) to be able to write generic code depending on both hidden value's type and types 'from the outside world' (sorry cannot explain it better :-( than this) I have tried various approaches, but if I 'visit' the any class adding a virtual function to reach hidden value I loose generic type information (lack of virtual template functions) from the outside while from the outside of any I cannot obtain directly the type of the hidden value ... is there a way to do the above ? Gianni Luciani

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Re: any question
by Kevlin Henney 09 Nov '01

09 Nov '01

> From: Thomas Matelich <toms-mailing-lists(a)home.com> > >In the docs, it uses a function called any_ptr, but I don't think it >exists. Could someone please explain? Yes, nothing more elaborate than a typo, I'm afraid! Should be any_cast. Kevlin ____________________________________________________________ Kevlin Henney phone: +44 117 942 2990 mailto:kevlin@curbralan.com mobile: +44 7801 073 508 http://www.curbralan.com fax: +44 870 052 2289 Curbralan: Consultancy + Training + Development + Review ____________________________________________________________

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casting shared_ptr while preserving use_count..
by John Liberty 09 Nov '01

09 Nov '01

I'd like to essentially downcast (to derived) from a base class with virtual methods while preserving (and incrementing) the use_count.. for an upcast, I can simply assign a shared_ptr<Child> to shared_ptr<Parent>. But for the downcast, I need to incorporate a dynamic_cast<childType> to get what I want.. With an older compiler that didn't like member templates, the boost conf would leave the internal pointer and use count as public, so I wrote my own casting function.. However, the newer compiler doesn't give this public access, so I may be stuck without modifying the header... any thoughts?

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How to build the latest release?
by Sinan 08 Nov '01

08 Nov '01

No matter what I try, ( I set JAMBASE, specified boost-base.jam etc... I always get the following error kanita% jam -f./tools/build/allyourbase.jam -sTOOLS="suncc" ./tools/build/allyourbase.jam: line 1608: syntax error at keyword ( don't know how to make all ...found 1 target... ...can't find 1 target... kanita% Line 1608 is the one that says: rule remember-binding ( target : bound-path ) { gBINDING($(target)) = $(bound-path) ; } ... How do I make jam understand the extended syntax ? ( Using FTjam 2.3.5 ...) Sinan Karasu ---------- # (C) Copyright David Abrahams 2001. Permission to copy, use, # modify, sell and distribute this software is granted provided this # copyright notice appears in all copies. This software is provided # "as is" without express or implied warranty, and with no claim as # to its suitability for any purpose. # compute directories for invoking WS6U2 WS6U2_BIN_DIRECTORY ?= $(WS6U2_ROOT_DIRECTORY)$(SLASH)bin ; WS6U2_BIN_DIRECTORY ?= "" ; # Don't clobber tool names if WS6U2_ROOT_DIRECTORY not set WS6U2_INCLUDE_DIRECTORY ?= $(WS6U2_ROOT_DIRECTORY)$(SLASH)include ; WS6U2_STDLIB_DIRECTORY ?= $(WS6U2_ROOT_DIRECTORY)$(SLASH)lib ; flags cc LINKFLAGS <runtime-link>static : -Bstatic ; flags cc CFLAGS <debug-symbols>on : -g ; flags cc LINKFLAGS <debug-symbols>on : -g ; flags cc CFLAGS <optimization>off : -xO0 ; flags cc CFLAGS <optimization>speed : -xO4 ; # Other optimizations we might want for WS6U2 # # flags cc CFLAGS <optimization>space : -xO2 ; flags cc CFLAGS <inlining>off : -xinline=no%func ; flags cc CFLAGS <inlining>on : -xinline=%auto ; flags cc CFLAGS <inlining>full : -xinline=%auto ; flags cc CFLAGS <profiling>on : -xpg ; flags cc LINKFLAGS <profiling>on : -xpg ; flags cc DEFINES <define> ; flags cc UNDEFS <undef> ; flags cc HDRS <include> ; flags cc STDHDRS : $(WS6U2_INCLUDE_DIRECTORY) ; flags cc STDLIBPATH : $(WS6U2_STDLIB_DIRECTORY) ; flags cc CFLAGS <shared-linkable>true : -KPIC ; flags cc LINKFLAGS <shared-linkable>true : -KPIC ; flags cc LINKFLAGS <target-type>DLL : -G ; flags cc LIBPATH <library-path> ; flags cc NEEDLIBS <library-file> ; flags cc FINDLIBS <find-library> ; #### Link #### rule Link-action { # This will appear before the import library name when building a DLL, but # will be "multiplied away" otherwise. The --exclude-symbols directive # proved to be neccessary with some versions of Cygwin. ##sik IMPLIB_COMMAND on $(<) = "-Wl,--exclude-symbols,_bss_end__:_bss_start__:_data_end__:_data_start__ -Wl,--out-implib," ; # IMPLIB_COMMAND on $(<) = "-Wl,--out-implib," ; cc-Link-action $(<) : $(>) ; } # for cc, we repeat all libraries so that dependencies are always resolved actions cc-Link-action bind NEEDLIBS { $(WS6U2_BIN_DIRECTORY)CC $(IMPLIB_COMMAND)$(<[2]) $(LINKFLAGS) -o "$(<[1])" -L$(LIBPATH) -L$(STDLIBPATH) "$(>)" "$(NEEDLIBS)" "$(NEEDLIBS)" -l$(FINDLIBS) -znodefs } # older actions # $(WS6U2_BIN_DIRECTORY)dlltool -e $(<[1]:S=:D=:G=) -l "$(<[2])" "$(>)" # $(WS6U2_BIN_DIRECTORY)CC $(LINKFLAGS) -L$(STDLIBPATH) "$(>)" "$(NEEDLIBS)" "$(NEEDLIBS)" -o "$(<[1])" #### Cc ##### rule Cc-action { cc-Cc-action $(<) : $(>) ; } actions cc-Cc-action { $(WS6U2_BIN_DIRECTORY)cc -c -U$(UNDEFS) -D$(DEFINES) $(CFLAGS) -I$(BOOST_ROOT) -I"$(HDRS)" -I"$(STDHDRS)" -o "$(<)" "$(>)" } #### C++ #### rule C++-action { cc-C++-action $(<) : $(>) ; } actions cc-C++-action { $(WS6U2_BIN_DIRECTORY)CC -c -U$(UNDEFS) -D$(DEFINES) $(CFLAGS) $(C++FLAGS) -I$(BOOST_ROOT) -I"$(HDRS)" -I"$(STDHDRS)" -o "$(<)" "$(>)" } #### Archive #### rule Archive-action { cc-Archive-action $(<) : $(>) ; } actions updated together piecemeal cc-Archive-action { ar ru "$(<)" "$(>)" } [Non-text portions of this message have been removed]

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any question
by Thomas Matelich 08 Nov '01

08 Nov '01

In the docs, it uses a function called any_ptr, but I don't think it exists. Could someone please explain? -- Thomas O Matelich Senior Software Designer Zetec, Inc. matelich(a)home.com tmatelich(a)zetec.com

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Boost release 1.25.1 now available
by Beman Dawes 07 Nov '01

07 Nov '01

Boost release 1.25.1 is now available at www.boost.org: * Boost Build System: Continued improvements. * Config Library: Continued refinements. * Graph Library: Final cleanup for upcoming the Boost Graph Library book. * Thread Library: Minor fixes - tests now pass on most Win32 and POSIX systems including Linux and Solaris. Semaphore removed as too error prone. * Function Library: direct support for member function pointers and documentation updates. * Boost-Users mailing list has been created to address topics of interest to users of Boost libraries. * Boost Wiki web added. Provides a place for Boost users to openly discuss and document the use of Boost libraries. It is not officially maintained by Boost developers. This release uses a new ftp program for updating the web site; the program used in the past was prone to get confused about dates, and didn't recover gracefully from network or server errors. Please let me know if you spot any out-of-date web pages on the site. --Beman

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Boost-Users announcement in 1.25.1
by Douglas Gregor 02 Nov '01

02 Nov '01

Hello all, We should announce the existence of the Boost-Users group in the 1.25.1 release of Boost. I've added a bullet to the "Latest News" entry for the release (just check index.htm in the top level of CVS). My two questions are: - Is there a more precise goal statement that should be in the announcement? (i.e., more precise that "address topics of interest to users of Boost libraries", which is intentionally vague) - Should we mention the Wiki? (with the usual not-Boost-moderated disclaimer) Doug

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RE: [Boost-Users] array -v- array_traits
by Jim.Hyslop 25 Oct '01

25 Oct '01

Duane Murphy [SMTP:duanemurphy@mac.com] wrote: > I noticed that array.hpp uses > > #ifndef BOOST_ARRAY_HPP > #define BOOST_ARRAY_HPP > .. > #endif > > and array_traits.hpp uses: > > #if !defined(BOOST_ARRAY_HPP) > #define BOOST_ARRAY_HPP 1 > .. > #endif > > This means that you cant use them both at the same time? The first one wins? > > These are certainly similar classes but they dont seem to collide. > > Is this a subtle bug or intentional? Hi, Duane. I don't know the answer, but I've cc'd this to the Boost developer's list. Someone there should have an answer ;-) -- Jim Hyslop (moderator, Boost-Users group)

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array -v- array_traits
by Duane Murphy 25 Oct '01

25 Oct '01

I noticed that array.hpp uses #ifndef BOOST_ARRAY_HPP #define BOOST_ARRAY_HPP .. #endif and array_traits.hpp uses: #if !defined(BOOST_ARRAY_HPP) #define BOOST_ARRAY_HPP 1 .. #endif This means that you cant use them both at the same time? The first one wins? These are certainly similar classes but they dont seem to collide. Is this a subtle bug or intentional? ..Duane

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FW: [boost] any
by Jim.Hyslop 19 Oct '01

19 Oct '01

rajanikanth jammalamadaka [SMTP:rajanik3@rediffmail.com] wrote: > Hi! Jim, > Could you please tell me why this code is not working: > > #include <iostream> > #include <boost/any.hpp> > using namespace boost; > int main() > { > > any holdsanything ; > holdsanything = 9; > std::cout<<holdsanything<<endl; > holdsanything = std::string("hello"); > std::cout<<holdsanything<<endl; > return 0; > } Hi, Raj You didn't specify what problems you were having. Am I correct in assuming you get a compiler error on the std::cout lines? If so, then the problem is that class 'any' does not have an extraction operator defined. If you change the lines to: std::cout << any_cast<int>(holdsanything)<<std::endl; and std::cout << any_cast<const char *>(holdsanything) << std::endl; it should work properly. -- Jim

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compiling boost on Win2k
by Mike Owens 19 Oct '01

19 Oct '01

I got a this suggestion from Damien Mulligan which worked really well. Use subst to map a drive letter to the path for the MSVC directory then use that drive letter in the VISUALC environment variable. Works like a charm. I should of thought of that. Thanks Damien. Mike > Date: Thu, 18 Oct 2001 08:12:05 -0400 > From: Anthony Kolarik <a.kolarik(a)computer.org> >Subject: RE: Digest Number 11 > >I don't have an answer for your specific JAM/Boost problem but I've seen >similar build problems (using cons)on NT and ended up using temp files to >hold the command line for the linker, rather than try to figure out why the >command lines worked fine on some machines and were too much for others. >You could look into registry settings to extend the buffer size for the >command interpreter but unless you can do it programmatically the temp file >approach would probably be a better. > -- Tony K.

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RE: [Boost-Users] Digest Number 11
by Anthony Kolarik 18 Oct '01

18 Oct '01

I don't have an answer for your specific JAM/Boost problem but I've seen similar build problems (using cons)on NT and ended up using temp files to hold the command line for the linker, rather than try to figure out why the command lines worked fine on some machines and were too much for others. You could look into registry settings to extend the buffer size for the command interpreter but unless you can do it programmatically the temp file approach would probably be a better. -- Tony K. > Date: Wed, 17 Oct 2001 15:47:58 -0700 > From: Mike Owens <mikeo(a)medifor.com> > Subject: Build Problem > > I am trying to build boost on windows 2000 and I get "The > input line is too > long" errors. I have included some sample output from jam. > Please note I > switched to short file names to try and alleviate this > problem. Anyone have > any suggestions on overcoming this problem? > > "C:\Progra~1\micros~2\VC98"\bin\cl /Zm400 -nologo -GX -c > -DNDEBUG > -DBOOST_ > RE_NO_LIB=1 /O2 /GX /GR /MD -I"libs\regex\build" > -I"libs\regex\build\..\..\.. > " -I""C:\Progra~1\micros~2\VC98"\include" > -Fo"libs\regex\build\bin\libboost_re > gex.lib\msvc\release\runtime-link-dynamic\posix_api.obj" > -Tp"libs\regex\build\. > ./src\posix_api.cpp" > > ...failed msvc-C++-action > libs\regex\build\bin\libboost_regex.lib\msvc\release\r > untime-link-dynamic\posix_api.obj ... > msvc-C++-action > libs\regex\build\bin\libboost_regex.lib\msvc\release\runtime-lin > k-dynamic\regex.obj > The input line is too long. >

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Build Problem
by Mike Owens 17 Oct '01

17 Oct '01

I am trying to build boost on windows 2000 and I get "The input line is too long" errors. I have included some sample output from jam. Please note I switched to short file names to try and alleviate this problem. Anyone have any suggestions on overcoming this problem? "C:\Progra~1\micros~2\VC98"\bin\cl /Zm400 -nologo -GX -c -DNDEBUG -DBOOST_ RE_NO_LIB=1 /O2 /GX /GR /MD -I"libs\regex\build" -I"libs\regex\build\..\..\.. " -I""C:\Progra~1\micros~2\VC98"\include" -Fo"libs\regex\build\bin\libboost_re gex.lib\msvc\release\runtime-link-dynamic\posix_api.obj" -Tp"libs\regex\build\. ./src\posix_api.cpp" ...failed msvc-C++-action libs\regex\build\bin\libboost_regex.lib\msvc\release\r untime-link-dynamic\posix_api.obj ... msvc-C++-action libs\regex\build\bin\libboost_regex.lib\msvc\release\runtime-lin k-dynamic\regex.obj The input line is too long.

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How about a link to the burgeoning Wiki?
by Jon Kalb 16 Oct '01

16 Oct '01

I've added a Wiki link to the Group Bookmarks and also a link to the FAQ on the Wiki. We need to build that up. :) I also added a link to the Group Bookmarks page on the Group home page. ===== Jon Kalb Kalb(a)LibertySoft.com __________________________________________________ Do You Yahoo!? Listen to your Yahoo! Mail messages from any phone. http://phone.yahoo.com

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precompiled jam executables uploaded
by Toon Knapen 13 Oct '01

13 Oct '01

I just uploaded precompiled jam executables to the Files section for linuxx86, irix and solaris. I also added an InstallingBoost page to the Wiki with links to these executables. I hope this helps people with using the Boost.Build system. I gzip'ed the executables (except for the linux one) since I'm not sure if users find it a hassle to gunzip them first. It would safe space in the Files section though. People with jam executables for other platforms, please add them or transfer them to me so I can put them on there. toon

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Building with Comeau
by Dale Peakall 12 Oct '01

12 Oct '01

Anyone had any success using the new build system with Comeau C++ on Win32 (MSVC6)? I'm using the pre-compiled Win32 jam binary from the FreeType project. Is this still suitable? I noticed Dave has checked in a whole bunch of changes to SourceForge. If not, is there an easy way to get the whole branch out of CVS? I've only ever used the web-interface which doesn't seem to provide this facility. The first problem I encountered was jam trying to use mv. After replacing the $(MV) instructions in the como-tools.jam with copy, I managed to get some obj files produced, but none of the libraries will link. First up, I noticed that the build system requires libcomo to be in a certain location, so I fixed that, but still nothing will link (lots of undefined external symbols - some to boost, some to std). I'm a Comeau newbie, so I may have messed up building libcomo (which would explain the missing std symbols), but not the missing boost symbols. Cheers, - Dale.

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boost/thread on Linux
by sebmarc＠yahoo.com 09 Oct '01

09 Oct '01

Has anyone successfully built boost/thread on Linux using g++ ?. I am getting two compilation errors. Seb.

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Thread Summary Experiment -- on the Wiki
by Jeff Garland 08 Oct '01

08 Oct '01

Last week we were having a discussion about the sort of content that might, or might not belong on the Wiki. I have tried another small experiment that might be a useful approach to augmenting the current boost information. The idea is to build a summary of mailing list discussion threads related to each library (or other topics). Many of the discussion on the mailing list can provide insight into the library design as well as solutions to specific problems not necessarily incorporated in the documentation. I built a small example for the function library. http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Function_Lib… -_Mail_Thread_Summary I have used the following convention for this: -- Order the thread names by date -- Title of the thread is either the email title, or a more precise title followed by the original thread title in parens The link performs a search that returns all the items in the thread from the yahoo groups site. One problem is that since the search is full text, some threads cannot be easily retrieved. For example searching "function review" will return a pile of email on threads and other topics unrelated to function. Despite the issues, this would seem to me this would be a useful contribution library users could build. Thoughts? Jeff

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concept_check and B&N trick
by Eric Ford 03 Oct '01

03 Oct '01

I ran into problems using BOOST_CLASS_REQUIRES in conjunction with the base class in the Barton-Nackman trick/Curiously recursive template technique. I want to require functions that take the derived type as an argument. So I declare a variable of the derived at struct level in the concept class, but then g++ (2.95) complains about it being an invalid use of undefined type... forward declaration... . Is there a way to make this work? If so, does anyone have/know of an example I can see how to order things to make it work? Thanks, E

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Building regex/1.25.0 with MSVC6SP5, STLPort 4.0
by Markus Schöpflin 02 Oct '01

02 Oct '01

Hi there, I've been trying to build the regex library but failed miserably. The compiler always dies with an error in "regex_traits.hpp" C:\boost_1_25_0\libs\regex\build>nmake INCLUDES="-I%STL_INCLUDE%" -fvc6-stlport.mak Microsoft (R) Program Maintenance Utility Version 6.00.8168.0 Copyright (C) Microsoft Corp 1988-1998. All rights reserved. if not exist "vc6-stlport\" mkdir vc6-stlport if not exist "vc6-stlport\vc6-stlport-re300m\" mkdir vc6-stlport\vc6-stlport-re300m cl -IC:\STL\STLport-4.0\stlport /nologo /MT /W3 /GX /O2 /GB /GF /Gy /I..\..\..\ /D_MT /DWIN32 /DNDEBUG /D_MBCS /D_LIB / YX /FD /c -Fpvc6-stlport/vc6-stlport-re300m/vc6-stlport-re300m.pch -Fo./vc6-stlport/vc6-stlport-re300m/ -Fdvc6-stlport/vc6-stlport-re300m.pdb ../src/c_reg ex_traits.cpp c_regex_traits.cpp ..\..\..\boost/regex/regex_traits.hpp(596) : error C2059: syntax error : '<' ..\..\..\boost/regex/regex_traits.hpp(596) : error C2238: unexpected token(s) preceding ';' ..\..\..\boost/regex/regex_traits.hpp(597) : error C2059: syntax error : '<' ..\..\..\boost/regex/regex_traits.hpp(597) : error C2238: unexpected token(s) preceding ';' ..\..\..\boost/regex/regex_traits.hpp(688) : error C2059: syntax error : '<' ..\..\..\boost/regex/regex_traits.hpp(688) : error C2238: unexpected token(s) preceding ';' ..\..\..\boost/regex/regex_traits.hpp(689) : error C2059: syntax error : '<' ..\..\..\boost/regex/regex_traits.hpp(689) : error C2238: unexpected token(s) preceding ';' ..\..\..\boost/regex/regex_traits.hpp(690) : error C2059: syntax error : '<' ..\..\..\boost/regex/regex_traits.hpp(690) : error C2238: unexpected token(s) preceding ';' NMAKE : fatal error U1077: 'cl' : return code '0x2' Stop. The error stays the same if I try the new build system with the following command line: jam -ftools/build/allyourbase.jam -sTOOLS="msvc" -sBUILD="<include>%STL_INCLUDE%" If I look at the offending line in "regex_traits.hpp" it reads const std::ctype<char>* pctype; Obviously it doesn't know that ctype lives in the std namespace. It works if I use the STL supplied by Microsoft. Does anyone else use this combination of compiler and library and managed to successfully build the regex library? Markus 'mar

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RE: [Boost-Users] Building regex/1.25.0 with MSVC6SP5, STLPort 4. 0
by Jim.Hyslop 02 Oct '01

02 Oct '01

Markus Schöpflin [SMTP:markus.schoepflin@ginit-technology.com] wrote: > I've been trying to build the regex library but failed miserably. The > compiler always dies with an error in "regex_traits.hpp" [...] > It works if I use the STL supplied by Microsoft. I don't use STLPort, but you might try a slight modification to boost/config/suffix.hpp. Search for BOOST_NO_STDC_NAMESPACE, and you'll see the line: namespace std { using ::ptrdiff_t; using ::size_t; } Try adding "using ::ctype;" into the list of using declarations. This may not work, though; I don't know if a using declaration can nominate the name of a template. -- Jim

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How about a link to the burgeoning Wiki?
by Tom Matelich 01 Oct '01

01 Oct '01

http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl

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RE: [Boost-Users] How about a link to the burgeoning Wiki?
by Jim.Hyslop 01 Oct '01

01 Oct '01

Paul Baxter [SMTP:paul_baxter@ntlworld.com] wrote: > Organised snippets from the mailing list (ala cpptips with the guru/C++ > newsgroups) and additional real user FAQs would seem the most useful content > to add to Wiki? That's the beauty of a Wiki: do you see something missing? *You* can add it! -- Jim

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Test #3
by david.abrahams＠rcn.com 28 Sep '01

28 Sep '01

Ce n'est pas une pipe [Moderators note] Pas du tout...

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