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[BGL] Is there a way to avoid a sequence of edges while traversing a Graph?
by Rohit Wadhwa 10 Aug '06

10 Aug '06

The problem we are trying to solve is as follows: The figure below describes a section of a graph. D ----------*--------------- | | | B F ----------*-------*-------* C | | | | | | ------------------*-------* A E We want to achieve the following via traversal: 1. Avoid the sequence from A->B->C->D. 2. Still be able to traverse to D from A via other paths, if available (eg. A->E, E->F, F->B, B->C, and C->D) We would like to be able to represent this in a graph (BGL) in a manner that will allow algorithms (such as DSP, connected_components etc.) to not take the 'prohibited path' into account. Is there a way to disable a particular path via traversal? Thanks in advance, Rohit.

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[program_options] changes in CVS are partial correct
by Ovanes Markarian 10 Aug '06

10 Aug '06

Hello, what should I do if changes in CVS are partial correct? Should I post correct one here or directly to CVS? With Kind Regards, Ovanes Markarian

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boost::logging - Problem with scoped log example.
by boost＠david-williams.info 10 Aug '06

10 Aug '06

Hi guys, I've just been experimenting with boost::logging. I've got some of the examples to work but can't get scoped logging to work. The folowing code should work, according http://www.torjo.com/code/log/scoped.html 1 : #include <boost/log/log.hpp> 2 : #include <boost/log/functions.hpp> 3 : 4 : using namespace boost::logging; 5 : 6 : int main(int argc, char** argv) 7 : { 8 : logger gui("app.gui"); 9 : gui.stream() << "hey - I've done something GUIsh" << std::endl; 10: 11: return 0; 12: } However I get a compile error saying: BuildTest\Main.cpp(9): error C2676: binary '<<' : 'boost::logging::logger_stream' does not define this operator or a conversion to a type acceptable to the predefined operator Any ideas? Thanks, David

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[program_options] bug or not... change proposal
by Ovanes Markarian 10 Aug '06

10 Aug '06

In my former post I wrote about assertions in program_options library... Since nobody answered I had to debug some boost::code. As I found out, current assertion of po relies in the following: in the function format_paragraph (option_description.cpp:365) is written: //... if (line_begin + (line_length - indent) > par_end) //... line_begin is of type std::string::const_iterator; line_length - indent is 51 in the last line only one word is written, which is shorter then 51 characters. By adding 51 to an iterator an assertion check is made, that the addition will produce an iterator out of string bounds. I know that iterators should behave like pointers, but in this case it is impossible to debug. Would be nice if some of boost developers decide to make a workaround. I will fix it locally. With Kind Regards, Ovanes Markarian

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Re: [Boost-users] Cross-compiling boost
by Hughes, James 10 Aug '06

10 Aug '06

Hi, I cross compile to an Arm platform with the following... bjam "-sGCC_ROOT_DIRECTORY=/opt/montavista/mobilinux/devkit/arm/iwmmxt_le" "-sGCC=iwmmxt_le-gcc" "-sGXX=iwmmxt_le-g++" stage This builds the libs to a stage folder, rather than installing them. You can then copy to the target from there. I used to get a hat load of compile faults, but it turned out to be a fault with the Montavista GCC compiler - fixed now. James > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Pfligersdorffer, Christian > Sent: 09 August 2006 14:51 > To: Boost-Users (E-Mail) > Subject: [Boost-users] Cross-compiling boost > > Dear boost-community, > > has anyone experience in cross-compiling boost? I tried to > build the whole thing using eldk ppc_6xx-gcc for linux @ > power pc, doing the build process on linux @ x86. It > generated object code for x86 whatever I did. Thought about > writing a toolset but I don't understand a single bit of what > happens in gcc-tools.jam :-( > > In effect I'd need the possibility to add a prefix for the > gcc-tools, because all the gcc, g++, ld etc. are named > ppc_6xx-gcc, ppc_6xx-g++, ppc_6xx-ld instead. And I'd want to > specify PPC as the target platform while building on a > different (x86) platform. > > Hoping that someone has an idea. > Yours, Christian Pfligersdorffer > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately.

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Cross-compiling boost
by Pfligersdorffer, Christian 10 Aug '06

10 Aug '06

Dear boost-community, has anyone experience in cross-compiling boost? I tried to build the whole thing using eldk ppc_6xx-gcc for linux @ power pc, doing the build process on linux @ x86. It generated object code for x86 whatever I did. Thought about writing a toolset but I don't understand a single bit of what happens in gcc-tools.jam :-( In effect I'd need the possibility to add a prefix for the gcc-tools, because all the gcc, g++, ld etc. are named ppc_6xx-gcc, ppc_6xx-g++, ppc_6xx-ld instead. And I'd want to specify PPC as the target platform while building on a different (x86) platform. Hoping that someone has an idea. Yours, Christian Pfligersdorffer

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Re: [Boost-users] random number generator 160 bit.
by james.jones＠firstinvestors.com 10 Aug '06

10 Aug '06

From: "chun ping wang" <cablepuff(a)gmail.com> > [code skipped] > T n(Random::randint<T>(numeric_cast<T>(pow(2.0, num_digits - 1)), > numeric_cast<T>(pow(2.0, num_digits))) > [code skipped] > > now num_digits is number of bits. If i pass 160 bit as like for DSA > algorithm the program crashes. I pass 8 and it works, how come? Is there a > better way to do this? Oh f is any function that can deteremine if a number > is most likely a prime or not.... My guess is that numeric_cast<T>(pow(2.0, num_digits)) throws an overflow exception. I don't know what you're using for T, but obviously even a long long can't hold a 160-bit integer (at least not on any architecture I'm aware of). To verify this, catch on overflow_error and see if this prevents the crash. - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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Boost.Random mt19937 seeding
by Matt Holland 10 Aug '06

10 Aug '06

Hi all, I'm having some difficulty understanding my options for seeding the base generators in mersenne_twister.hpp. I'm interested in the array initialization that is somewhat obtusely mentioned in the documentation. In boost/random/mersenne_twister.hpp I see the following relevant items: template<class It> mersenne_twister(It& first, It last) { seed(first,last); } ... template<class It> void seed(It& first, It last) { int j; for(j = 0; j < n && first != last; ++j, ++first) x[j] = *first; i = n; if(first == last && j < n) throw std::invalid_argument("mersenne_twister::seed"); } I gather that "It" is some kind of iterator, and the natural candidate would be something like std::vector<uint32_t>::iterator, but not having truly come to terms with templates, it is unclear to me how to actually call this. The following minimal code snippet fails to compile with g++ (gcc version 3.3 20030304 (Apple Computer, Inc. build 1671)). Errors below. #include <iostream> #include <vector> #include <boost/random.hpp> typedef boost::mt19937 Mt19937BaseGenerator; // base generator typedef boost::uniform_real<> UniformReal; // distribution // variate generator typedef boost::variate_generator<Mt19937BaseGenerator&, UniformReal> Mt19937UniformRealGenerator; int main() { std::vector<uint32_t> seedVector(4); seedVector[0] = 12345u; // make up some seeds seedVector[1] = 98765u; seedVector[2] = 12942u; seedVector[3] = 20343u; // attempt to seed with vector iterators Mt19937BaseGenerator mt19937Generator(seedVector.begin(), seedVector.end()); UniformReal distribution(0, 1); Mt19937UniformRealGenerator myGen(mt19937Generator, distribution); for (unsigned i = 0; i < 100; ++i) { std::cout << myGen() << std::endl; } return 0; } mt19937Seed.cpp: In function `int main()': mt19937Seed.cpp:18: error: no matching function for call to ` boost::random::mersenne_twister<uint32_t, 32, 624, 397, 31, 0x09908b0df, 11, 7, 0x09d2c5680, 15, 0x0efc60000, 18, 0x0c77666de>::mersenne_twister( __gnu_cxx::__normal_iterator<uint32_t*, std::vector<uint32_t, std::allocator<uint32_t> > >, __gnu_cxx::__normal_iterator<uint32_t*, std::vector<uint32_t, std::allocator<uint32_t> > >)' /sw/include/boost/random/mersenne_twister.hpp:43: error: candidates are: boost::random::mersenne_twister<uint32_t, 32, 624, 397, 31, 0x09908b0df, 11, 7, 0x09d2c5680, 15, 0x0efc60000, 18, 0x0c77666de>::mersenne_twister(const boost::random::mersenne_twister<uint32_t, 32, 624, 397, 31, 0x09908b0df, 11, 7, 0x09d2c5680, 15, 0x0efc60000, 18, 0x0c77666de>&) /sw/include/boost/random/mersenne_twister.hpp:69: error: boost::random::mersenne_twister<UIntType, w, n, m, r, a, u, s, b, t, c, l, val>::mersenne_twister(It&, It) [with It = __gnu_cxx::__normal_iterator<uint32_t*, std::vector<uint32_t, std::allocator<uint32_t> > >, UIntType = uint32_t, int w = 32, int n = 624, int m = 397, int r = 31, UIntType a = 0x09908b0df, int u = 11, int s = 7, UIntType b = 0x09d2c5680, int t = 15, UIntType c = 0x0efc60000, int l = 18, UIntType val = 0x0c77666de] /sw/include/boost/random/mersenne_twister.hpp:68: error: boost::random::mersenne_twister<UIntType, w, n, m, r, a, u, s, b, t, c, l, val>::mersenne_twister(UIntType) [with UIntType = uint32_t, int w = 32, int n = 624, int m = 397, int r = 31, UIntType a = 0x09908b0df, int u = 11, int s = 7, UIntType b = 0x09d2c5680, int t = 15, UIntType c = 0x0efc60000, int l = 18, UIntType val = 0x0c77666de] /sw/include/boost/random/mersenne_twister.hpp:60: error: boost::random::mersenne_twister<UIntType, w, n, m, r, a, u, s, b, t, c, l, val>::mersenne_twister() [with UIntType = uint32_t, int w = 32, int n = 624, int m = 397, int r = 31, UIntType a = 0x09908b0df, int u = 11, int s = 7, UIntType b = 0x09d2c5680, int t = 15, UIntType c = 0x0efc60000, int l = 18, UIntType val = 0x0c77666de] Any help? I always have a really hard time interpreting template-related compiler errors. Thanks, Matt -- Matt Holland Population Biology Graduate Group University of California Davis, CA 95616

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boost::serialization - serializing boost::smart_ptrs won't work
by Sascha Friedmann 09 Aug '06

09 Aug '06

Hello, I have a problem with serializing smart_ptrs. I have tried both the boost::scoped_ptr and the boost::shared_ptr but I get always the same error: Boost1-33\include\boost-1_33\boost\archive\detail\oserializer.hpp(566): error C2027: Use of undefined type "boost::STATIC_ASSERTION_FAILURE<x>" with [ x=false ] My example program: #include <boost/archive/tmpdir.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/shared_ptr.hpp> struct Foo { int i; Foo( int j ) : i( j ) { } template< class T > void serialize( T& ar, const unsigned int ver ) { ar & i; } }; struct Test { boost::shared_ptr< Foo > t1; boost::shared_ptr< Foo > t2; Test() : t1( new Foo( 3 ) ), t2( t1 ) { } template< class Ar > void save( Ar& ar, const unsigned int ver ) { ar << t1; ar << t2; } template< class Ar > void load( Ar& ar, const unsigned int ver ) { ar >> t1; ar >> t2; } BOOST_SERIALIZATION_SPLIT_MEMBER(); }; int main( int argc, char* argv[] ) { Test t; std::ofstream ofs( "test.txt" ); boost::archive::text_oarchive out( ofs ); out << t; } I hope someone can help me (google and the documentation couldn't :() Sascha Friedmann

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[lambda] Correct way to use lamda with boost.array?
by Michael Marcin 09 Aug '06

09 Aug '06

What is the proper syntax for using lamda with with array? i.e. how do I do something like namespace lambda = ::boost::lambda; boost::array< boost::array<int,2>, 4 > foo = {{ {-1,1}, {0,0}, {1,-1}, {2,-2} }}; std::for_each( foo.begin(), foo.end(), std::cout << lambda::constant( "first = " ) << lambda::_1[0] << ' ' << lambda::constant( "second = " ) << lambda::_1[1] << '\n' ); Thanks

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