March 2005 - Boost - lists.boost.org

Is there any way to get typeid() to return the derived class name?
by Chris Just 01 Mar '05

01 Mar '05

Hi, I've been looking through the boost library and I haven't been able to find anything that works like typeid() that returns the exact (i.e. derived) class name instead of just the base class. I want to compare two derived classes to make sure that they are of the same class, but typeid() only returns the name of the base class. If there is a boost function that does this, or if someone has a way of doing it could you please point me in the right direction? Thanks, Chris Just __________________________________ Do you Yahoo!? Yahoo! Mail - You care about security. So do we. http://promotions.yahoo.com/new_mail

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[mpl] sequence details
by Tobias Schwinger 01 Mar '05

01 Mar '05

Hi, What is the best way to convert the result of a mutating mpl intrinsic metafunction (such as 'mpl::push_back', for example) to numbered form ('vectorN<a1,a2,..>') ? I tried using the type-member (which only works on some compilers - not with GCC for example) and figure 'copy' could probably do the trick (but is a quite complex operation) so there might be a better recipe for this. In a library I'm currently working on, I use a decorator pattern to make a class model of a sequence it holds (i.e. give it a tag type member and specialize *_impl with delegate semantics). After applying the delegate metafunction I need the sequence in a form I can match with partial specialization. Thanks for your help, Tobias

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[numeric/conversion] doc's example not up-to-date
by Samuel Krempp 01 Mar '05

01 Mar '05

Is the documentation for numeric/conversion finalized yet ? It seems that at least the code sample in numeric/conversion/doc/numeric_cast.html hasn't been kept up-to-date. This sample 1/ includes inexistent header 2/ uses boost::bad_numeric_cast instead of boost::numeric::bad_numeric_conversion and same for the other exception classes and most of all : 3/ // This works, because unsigned integral types cannot cause overflow. unsigned char c=numeric_cast<unsigned char>(l); But this line does raise an overflow exception (as it should, I guess). I guess the comment was about unsigned types implementing modulo-arithmetics, but in the end does numeric_cast check for unsigned overflows, or not ?? -- Samuel

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Re: [boost] Re: review of FSM nears to the end - any more reviews?
by Iain Hanson 01 Mar '05

01 Mar '05

Hi, On Tue, 2005-03-01 at 02:56 +0100, Pavel Vozenilek wrote: > "Jonathan Turkanis" wrote: > > [snip] > > I think the review should be extended. If you do so, > > I will commit to writing a > > review, even though I don't know much about FSMs. I am also working on a review of the library and will submit it in a couple of days. > > > > I have not read the FSM reviews yet, but unfortunately IMO even if all the > > reviews are very favorable there simply have not been enough yet to > > justify > > accepting a medium sized library. It looks to me like only four people > > other > > than you and Andreas have posted on FSM so far. I agree. > Perhaps it could be interpreted: as the library reached > mature state where everybody's happy enough. > No. I think that silence is probably better interpreted as apathy or I don't have enough time to review something of this size and do it justice. I would not like to see libraries adopted into boost by default when they have not received a decent review. Just my 2p worth. > I feel current model of reviews is not designed > to deal with big libraries well. > I very much agree. /ikh

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mpl::vector & push_back question ?
by Zhang, Karl 01 Mar '05

01 Mar '05

Hi: When I am reading mpl source code. I notice that push_bck algorithm, Look as following: template<> struct push_back_traits< aux::vector_tag > { template< typename Vector, typename T > struct algorithm { typedef vector_node<T,Vector> type; }; }; My question is: when generate new sequence, vactor_node<T, vector>, why skip "size" argument ? How does it increase sequence size in push_back? About push_front, It increase sequence size when generating new sequence. Regard Karl

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RE: [boost] Re: Iostreams Question: Best way to output towin32debugger\outwindow ?
by Brian Braatz 01 Mar '05

01 Mar '05

> -----Original Message----- > On Behalf Of Jonathan Turkanis > Sent: Monday, February 28, 2005 3:09 PM > > Brian Braatz wrote: > > First off THANK YOU Johnathon Turkanis for help with "tee" earlier. > > That saved me a great amount of pain. > > Glad to be of service ;-) > [Brian Braatz Writes:] :) > > Below is part of what I am trying to use it with. > > > > My next question is what is the best way to deal with an "output" > > device having a different cr\lf than another one? > > Have you tried to use a newline filter: > > http://www.kangaroologic.com/iostreams/libs/iostreams/doc/?path=6.2.2 > [Brian Braatz Writes:] I have this sinking feeling this is like when I am standing in front of the fridge and say "Honey, WHERE IS THE MILK?" > ? > > I'm not familiar with the function OutputDebugString, but you might be > able to > do this: > > struct debug_out_sink : boost::iostreams::sink > { > void write(const char* s, std::streamsize n) > { > std::string s(s, n); > OutputDebugString(s.c_str()); > } > }; > > void Test_Profile() > { > // Note: library now uses namespace iostreams > > using namespace boost::iostreams; > filtering_ostream out; > std::ofstream log("log.txt"); > debug_out_sink dbosink; > out.push(tee(log)); > out.push(tee(std::cout)); > out.push(newline_filter(newline::windows)); > out.push(dbosink); > > out << "LINE ONE" << endl > << "Next line" << endl > << "third line" << endl; > } > > Jonathan [Brian Braatz Writes:] OutputDebugString() is a win32 function, basically when you build your app and hit the "debug" button in the IDE, it launches your app as a child process. If your app calls OutputDebugString() the text sent is marshaled across the process boundaries back to the parent process (MSVC debugger) and then it puts the string into the "debug window" in the IDE. (I point this out because it is semi-important to note that the process OutputDebugString has to go through is SLOW. I.e. just for reference, you would NOT want to call OutputDebugString() for each char) The problem with above, IF I UNDERSTAND iostreams properly, is that I just want a filter on the debug_out_sink because it needs the \r\n. Everything else needs a \n. Doesn't the above line apply the filter to everything? Do I need to weave in the filter on the debug_out_sink class? (either by "has a" or "is a")? What I am after is the "user" of debug_out_sink can just "push" it in without having to know about \r\n vs \n weirdness.

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Global cleanups and typo fixes (affects whole tree)
by Julio M. Merino Vidal 01 Mar '05

01 Mar '05

Hi, I'm resending here several typo fixes and other whitespace/indentation cleanups I've been sending during the last few days (in these messages): http://lists.boost.org/MailArchives/boost/msg79319.php http://lists.boost.org/MailArchives/boost/msg79267.php (Can't find the third one in the archives.) This message follows David Abrahams suggestions (as seen in http://lists.boost.org/MailArchives/boost/msg79323.php) I.e., non-gzipped attachment, a single patch containing everything, and a descriptive subject line mentioning that it affects the global tree. Note that the patch is straightforward and non-intrusive. It mostly fixes several typos found in documentation and comments, and also solves some formatting issues in the jam build files (incorrect indentation and very long lines in help messages). In case you have questions about some changes (I really doubt so), the previous emails (linked at the beginning) have some more information. I hope it's better now. Thanks, -- Julio M. Merino Vidal <jmmv84(a)gmail.com> http://www.livejournal.com/users/jmmv/ The NetBSD Project - http://www.NetBSD.org/

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RE: [boost] Re: Re: Iostreams Question: Best way tooutputtowin32debugger\outwindow ?
by Brian Braatz 01 Mar '05

01 Mar '05

Are you running it in VC in debug mode? (you have to do Debug-Start from the IDE- then View Menu- Other Windows- Output- you might have to scroll it) Too bad we don't have a boost.socket, because it would be fairly reasonable to take and make a sink for debug out, on windows it would use OutputDebugString- or on windows \ unix\ it could spit debug info to a socket). If we had a Socket library, all the rest of the pieces are there... I am going farther down the profiling path, (and Christopher Diggins has been INCREDIABLY helpful there). But as I think about it- boost isn't really that far off from having a profiler\debugger\logger. I think the iostreams lib would be an excellent thing to build that on top of... Anyways, just mindless meandering.. Ill give the code below a run tonight and see if it works for me (3-4 hours from now). > -----Original Message----- > From: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] > On Behalf Of Jonathan Turkanis > Sent: Monday, February 28, 2005 5:11 PM > To: boost(a)lists.boost.org > Subject: [boost] Re: Re: Iostreams Question: Best way > tooutputtowin32debugger\outwindow ? > > Okay Brian, > > The following apparently works, but when OutputDebugString is called I > don't see > any output. I'm not sure if the previous version worked or not; I've run > out of > time for now. > > Jonathan > > struct debug_out_sink : boost::iostreams::sink { > debug_out_sink () > { > using namespace boost::iostreams; > chain_.push(newline_filter(newline::windows)); > chain_.push(debug_out_sink_impl()); > } > > void write(const char* s, std::streamsize n) > { > chain_.write(s, n); > } > > boost::iostreams::detail::chain<boost::iostreams::output> chain_; > }; > > > > > > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost

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multi_index_container
by Volker Vieth 01 Mar '05

01 Mar '05

Hi, using multi_index_container I've got strange errors. Simple source code leaned on official examples doesn't compile. Hardly modified code that seems to be equivalent does compile however. I've reduced it to two examples. I'm using Visual C++ .NET 7.09466 (i.e. cl.exe 13.00.9466) with boost 1.32.0 under Win XP. This first example is a shortened version of boost_1_32_0\libs\multi_index\example\basic.cpp. It reveals 4 subversions, but 2 of them only compile without erros. Why the other don't? 01 #include <boost/multi_index_container.hpp> 02 #include <boost/multi_index/member.hpp> 03 #include <boost/multi_index/ordered_index.hpp> 04 #include <string> 05 06 using boost::multi_index_container; 07 using namespace ::boost; 08 using namespace boost::multi_index; 09 10 11 struct employee 12 { 13 int id; 14 std::string name; 15 int age; 16 17 employee(int id_,std::string name_,int age_):id(id_),name(name_),age(age_){} 18 }; 19 20 21 struct id{}; 22 struct name{}; 23 struct age{}; 24 25 26 typedef multi_index_container< 27 employee, 28 indexed_by< 29 ordered_unique< 30 tag<id>, BOOST_MULTI_INDEX_MEMBER(employee,int,id)>, 31 ordered_non_unique< //remove for versions C, D 32 tag<name>,BOOST_MULTI_INDEX_MEMBER(employee,std::string,name)>, 33 ordered_non_unique< 34 tag<age>, BOOST_MULTI_INDEX_MEMBER(employee,int,age)> > 35 > employee_set; 36 37 38 //use exact one of following versions, remove the other lines 39 40 //version A: does NOT compile 41 //causes basic.cpp(42) : error C2976: 'boost::multi_index::index' : too few template arguments 42 typedef employee_set::index<id>::type employee_set_by_id; 43 44 //version B: DOES compile 45 typedef index<employee_set,id >::type employee_set_by_id; 46 typedef index<employee_set,age>::type employee_set_by_age; 47 48 //remove the name index (lines 31, 32) for following versions 49 50 //version C: DOES compile 51 typedef index<employee_set,id >::type employee_set_by_id;; 52 53 //version D: does NOT compile 54 //causes ...\include\boost-1_32\boost\mpl\vector\aux_\preprocessed\no_ctps\vector10.hpp(398) : 55 // error C2039: 'item3' : is not a member of 'boost::mpl::vector2<T0,T1>' 56 typedef index<employee_set,age>::type employee_set_by_age; My second example consists of 2 tiny programs. The former compile fine. Using the qualified name should do the same, but outputs ...\include\boost-1_32\boost\multi_index_container.hpp(60) : error C2039: 'multi_index_node_type' : is not a member of 'boost::detail' Where's the difference? 60 #include <boost/multi_index_container.hpp> 61 #include <boost/multi_index/ordered_index.hpp> 62 63 using boost::multi_index_container; 64 65 int main( int argc, char* argv[] ) 66 { 67 multi_index_container< int > mic; 68 return 0; 69 } 70 #include <boost/multi_index_container.hpp> 71 #include <boost/multi_index/ordered_index.hpp> 72 73 int main( int argc, char* argv[] ) 74 { 75 boost::multi_index_container< int > mic; 76 return 0; 77 } -- DSL Komplett von GMX +++ Superg�nstig und stressfrei einsteigen! AKTION "Kein Einrichtungspreis" nutzen: http://www.gmx.net/de/go/dsl

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IoStreams- can it basically work in vc70 with limited functionality ? was[ RE: Iostreams Question: Best way to output to win32 debugger\outwindow ?]
by Brian Braatz 01 Mar '05

01 Mar '05

In working with the code below, I just moved it to VC70. The iostreams docs point me to not officially supporting vc71, but they do say some of the support has been left in. While trying to compile below, I got caught up with a static assert, I noticed the #ifndef BOOST_IOSTREAMS_NO_FULL_SMART_ADAPTER_SUPPORT Was around the static assert. So being a gambling sorta guy, I #defined BOOST_IOSTREAMS_NO_FULL_SMART_ADAPTER_SUPPORT and that got rid of that static assert. I am now having issues with detail::resolve_traits // Deduces the return type of resolve. template<typename Mode, typename Ch, typename T> struct resolve_traits { BOOST_STATIC_ASSERT(!is_const<T>::value); I have been digging through trying to figure this one out. I have not yet. My Question- is there a workaround that allows for minimal \ limited useage of iostreams with VC70. (I have a project I am working on code for that is STUCK on that compiler).. The code below is what I am trying to make work. Many Thanks, Brian -----Original Message----- From: Brian Braatz Sent: Monday, February 28, 2005 1:54 PM To: 'boost(a)lists.boost.org' Subject: Iostreams Question: Best way to output to win32 debugger\outwindow ? First off THANK YOU Johnathon Turkanis for help with "tee" earlier. That saved me a great amount of pain. Below is part of what I am trying to use it with. My next question is what is the best way to deal with an "output" device having a different cr\lf than another one? My basic problem is this- I want to be able to take cout << "hi" << endl << "there" << endl; and have it properly give an end of line for the MSVC debugger (the same issue exists with the windows edit control) the problem is with both the windows edit control and the MSVC debug out window, you need to give it a \r\n instead of just a \n As you will see in my code below, there is "stupidity" (i.e. look for the memcpy :) ) My question is this- What is your suggested way to do what I am trying to do. (code below DOES work) using namespace std; using namespace boost::io; struct tee : boost::io::multichar_output_filter { tee(std::ostream& dest) : dest(dest) { } template<typename Sink> void write(Sink& snk, const char* s, std::streamsize n) { // Write to the downstream Sink boost::io::write(snk, s, n); // Write to the stored ostream: dest.write(s, n); } std::ostream& dest; }; struct debug_out_sink : public sink { debug_out_sink() { } void write( const char* s, std::streamsize n) { // copy the incoming data into a new location so we can NULL terminate char * sout = new char[(n+1)*2]; memcpy(sout,(void*)s,n); sout[n] = 0; // make a std::string from null terminated string std::string ssOut = sout; // replace all occurances of \n with \r\n // this is the end of line sequence used for the win32 debugger // (this is also for edit controls on the windows platform) boost::replace_all(ssOut,"\n","\r\n"); OutputDebugString(ssOut.c_str()); // clean up delete [] sout; sout = NULL; } }; void Test_Profile() { using namespace boost::io; filtering_ostream out; std::ofstream log("log.txt"); debug_out_sink dbosink; out.push(tee(log)); out.push(tee(std::cout)); out.push(dbosink); out <<"LINE ONE" << endl << "Next line" << endl << "third line" << endl; }

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