- Boost-users - lists.boost.org

RE: [Boost-users] Spirit
by Foster, Gareth 15 Oct '04

15 Oct '04

Thanks Ron, Joel, What i was after was the link Joel actually posted, but thats for the tip anyway Ron. Much appreiated both. Now i just have to get boost working with cygwin :) Regards, Gaz -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Ronald Garcia Sent: 14 October 2004 17:21 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Spirit Are you referring to code that translates C++ into an xml-ish parse tree, or code that makes c++ code look pretty as html? I am aware of an html pretty-printing program for c++ sources written using boost.regex, if that's what you seek. Cheers, Ron On Oct 14, 2004, at 8:24 AM, Foster, Gareth wrote: Hello all, I am trying to find some source code that uses spirit to parse C++ and convert it to HTML, i found some on google, but i misplaced it and i can't find it again. It looked like it could have been an example provided with the library, but i can't see it listed in the documentation. On a side note, anyone know the best way to use boost with cygwin? From source? Is there even another way? Thanks for any help! Gaz _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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for_each on container of any
by Frank Birbacher 15 Oct '04

15 Oct '04

Hello! I like the idea of containers (e.g. std::vector) of boost::any. But I'd like to execute some operation on each item of the sequence. Unfortenuately I would need to know the set of types in the container and check every one of them if I was going to use the std::for_each with a void(*)(boost::any&). That's not good at all. I'd like to pass a function object like: struct MyOperation { template<typename T> void operator() (T&) const; }; How can I do so? Is there any algorithm for doing so provided by boost? Frank

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max_element matrix
by Vicente Palazón González 15 Oct '04

15 Oct '04

Hello, sorry, I'm a beginner with uBLAS, and I think these are simple questions, is there a simple way to obtain the maximum element of an uBLAS matrix? is there an special iterator for ubLAS matrices to use with std::max_element? Vicente Palazón.

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BOOST_STATIC_ASSERT with intel compiler at class scope
by Thomas S. Urban 15 Oct '04

15 Oct '04

The BOOST_STATIC_ASSERT documentation indicates I can use it at template class scope (private recommended) - the assert shouldn't get triggered unless the class is instantiated. This seems to work ok with gcc-3.* but not with the intel compiler (8.1). // begin example program #include "boost/static_assert.hpp" template<class T> struct foo { foo (int) { } private: BOOST_STATIC_ASSERT (false); }; template <> struct foo<int> { foo (int i) { } }; int main () { foo<int> f (7); } // end example program I get the following error: foo.cpp(8): error: incomplete type is not allowed BOOST_STATIC_ASSERT (false); ^ compilation aborted for foo.cpp (code 2) Whether I provide the specialization for int or not, or whether I ever use struct foo in main or not. Is this a know issue? Do I have a build problem? I'm using boost version 1.30.2. Thanks Scott

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Spirit
by Foster, Gareth 14 Oct '04

14 Oct '04

Hello all, I am trying to find some source code that uses spirit to parse C++ and convert it to HTML, i found some on google, but i misplaced it and i can't find it again. It looked like it could have been an example provided with the library, but i can't see it listed in the documentation. On a side note, anyone know the best way to use boost with cygwin? From source? Is there even another way? Thanks for any help! Gaz

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boost::bind, MSVC7.1 and volatile-qualification
by Schalk_Cronje＠McAfee.com 14 Oct '04

14 Oct '04

Is there a known problem with boost::bind, volatile-qualified member functions and MSVC7.1? The following snippet of code happily compiles with various incantations of gcc, but fails with MSVC7.1. The same applies for 'const volatile'. #include <boost/function.hpp> #include <boost/bind.hpp> struct TEST { void gv0() volatile; void gvc0() volatile const; int gv2(int,int) volatile; int gvc2(int,int) volatile const; }; void instantiate() { TEST T; boost::function< void() > gv0 =boost::bind(&TEST::gv0,&T); // boost::function< int(int,int) > gv2 =boost::bind(&TEST::gv2,&T,_1,_2); // boost::function< void() > gcv0=boost::bind(&TEST::gvc0,&T); // boost::function< int(int,int) > gcv2=boost::bind(&TEST::gvc2,&T,_1,_2); } cl -c -TP -GS -GF -GR -vmv -vmg -EHsc -Zc:forScope -Zc:wchar_t -Op -Gm- -D_DEBUG -Od -Zi -Yd -MDd msvc71bind.cpp (Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.10.3077 for 80x86) ******\boost\mem_fn.hpp(256) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\bind\bind_template.hpp(156) : see reference to class template instantiation 'boost::_mfi::dm<R,T>' being compiled with [ R=void (void) volatile, T=TEST ] msvc71bind.cpp(21) : see reference to class template instantiation 'boost::_bi::bind_t<R,F,L>' being compiled with [ R=void (__thiscall &)(void) volatile, F=boost::_mfi::dm<void (void) volatile,TEST>, L=boost::_bi::list_av_1<TEST *>::type ] ******\boost\mem_fn.hpp(264) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\mem_fn.hpp(274) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\mem_fn.hpp(288) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\mem_fn.hpp(293) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\mem_fn.hpp(307) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\bind.hpp(1572) : warning C4180: qualifier applied to function type has no meaning; ignored msvc71bind.cpp(21) : see reference to function template instantiation 'boost::_bi::bind_t<R,F,L> boost::bind<void(void) volatile,TEST,TEST*>(void (__thiscall TEST::* ),A1)' being compiled with [ R=void (__thiscall &)(void) volatile, F=boost::_mfi::dm<void (void) volatile,TEST>, L=boost::_bi::list_av_1<TEST *>::type, A1=TEST * ] ******\boost\mem_fn.hpp(286) : error C4716: 'boost::_mfi::dm<void __thiscall TEST::(void)volatile ,TEST>::operator()' : must return a value

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Re: Extending the boost::thread class
by arno.schaefer＠sqs.de 14 Oct '04

14 Oct '04

> For what it's worth, William Kempf began an implementation of thread > priorities and an exception-based thread cancellation scheme on the > thread_dev branch before he stopped working on Boost.Threads. If it's > completed enough (I haven't examined it closely enough yet to tell), > I hope to move it into the a Boost release after the upcoming 1.32. > That won't help you right now, however. I feel sorry about that, but perhaps it is possible to get a look to the actual state? Arno

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Boost & VC2005 (Whidbey)
by S.I.M. van Keulen 14 Oct '04

14 Oct '04

Hi all, recently I started 'porting' some projects to 64 bit Windows (AMD) using Visual Studio 2005. I noticed that the Compiler had trouble with Boost. Searching the net didn't provide much helpfull information. I wondered if any of you had tried anything with Boost and VC2005/Whidbey compilers. Or if any of you could direct me to some information source on the net. Thank you! Serge van Keulen

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Re: "smart list" container?
by David Jones 13 Oct '04

13 Oct '04

"Caleb Epstein" <caleb.epstein(a)gmail.com> wrote in message news:<989aceac041012063240b6aa3(a)mail.gmail.com>... > On Mon, 11 Oct 2004 10:19:54 -0600, David M. Jones <djones(a)keymark.com> wrote: > > - The container itself would act more or less identically to std::list; > > - The iterators on the container would act like boost::weak_ptr in that they > > would know that they are invalid when the list element that they point to is > > removed. > > Can't you just do this with a std::list<boost::shared_ptr>? You can > convert the *iterators to weak_ptrs as needed. Or am I missing > something? There are a couple of reasons that std::list<boost::shared_ptr> is less than ideal. First, using the algorithms becomes cumbersome/annoying. Instead of being able to write std::list<boost::shared_ptr<int> > lst; // ... Populate the list int i; // ... Set the value of i std::list<boost::shared_ptr<int> >::iterator = std::find(lst.begin(), lst.end(), i); I instead need to create a function object to represent a boost::shared_ptr<int> having the desired value and then use find_if(). Second, I would lose the ability to store iterators and then check them later for validity. Suppose that I have a std::list<boost::shared_ptr<int> > named lst and I have two std::list<boost::shared_ptr<int> >::iterator objects it1 and it2 that happen to reference the same node in the list. If I call lst.erase(it1) then it2 also becomes invalid. If I call boost::weak_ptr<int>(*it2) I get an error because I cannot dereference the iterator because it is already invalid. This is how std::list objects are supposed to work but what I want to be able to do is now call something like it2.expired() to determine that the node being refered to by it2 is not invalid/expired/removed. One way to get around this is to store boost::weak_ptr objects derived from std::list<boost::shared_ptr>::iterator objects instead of storing it1 and it2 directly. But then I lose the advantage of having stored iterators: I cannot (after checking for expiration and being at the end of the list) call operator++() to move the iterator forward. Fundamentally, I don't want to be storing a "list of nodes of shared pointers of objects" but a "list of nodes of objects whose pointers to each other are shared pointers". And I want the iterators to be weak pointers to the nodes. Potentially a way to do this would be to write a custom allocator my_alloc that declares typedef boost::shared_ptr pointer; and then create a std::list<T, my_alloc<T> > This works because std::list uses the allocator rebinding mechanism to call my_alloc<node<T> > rather than my_alloc<T>. (In fact, my_alloc<T> is never used to allocate anything in std::list<T>!) However, there is a problem because the interface (concept a la Austern) of boost::shared_ptr is different than that of a regular pointer. So when the std::list code tries to call _Myhead = 0; I get a compiler error. (I am using MSVC 7.1: although this particular error may be STL implementation dependent, I do believe that the problem I am describing will occur with any STL implementation.) But I digress... The question of why the boost::shared_ptr interface/concept does not conform to that of a normal pointer is probably a topic for a separate posting.

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RE: [Boost-users] Extending the boost::thread class
by Foster, Gareth 13 Oct '04

13 Oct '04

Could you make it something like "enum { eLow, eNormal, eHight }; myThread.priority(eHigh);"? Maybe something non specific would be do-able, and it might still be useful to those who aren't after lots of control? Not that I am well clued up, just a thought. Cheers! Gaz -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Ben Hutchings Sent: 13 October 2004 17:45 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Extending the boost::thread class arno.schaefer(a)sqs.de wrote: > Hi all, > I want to use the boost thread library as a base for my multiplatform > thread class. After I have studied the documentation I recognize that > there are not all things available at the moment what I need, so I try > to find out what is the best way to start my implementation. What I > need, is to implement the following additional methods: suspend, resume, > stop (or terminate), set_priority, get_priority, get_state and I want to > have the possibility to create threads in a suspend mode. <snip> Why do you think you want suspend, resume and terminate? There are very few safe uses for these operations, and programs that use them tend to suffer from data corruption and/or deadlocks. It would be fairly easy to add support for priority settings to Boost.Thread, but since priority values are only meaningful in the context of a scheduling policy and policies vary between operating systems it would be hard to provide a genuinely portable priority system. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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