July 2009 - Boost-users - lists.preview.boost.org

boost programmer_option.hpp
by Narendra R 09 Jul '09

09 Jul '09

Hi, i was trying to use boost program option I can compile the code written using the program_option.hpp, but i am getting linker error can any one help me? Using gcc compiler

2 1

Possible to put path to boost library somewhere else than Jamroot file?
by s seelenluft 09 Jul '09

09 Jul '09

Hi, my question is whether I can put the path to the boost library in a another file than the Jamroot file (eg, boost-build.jam)? I run run longish simulations on multiple workstations, essentially Debian and Mac OS X machines. For good or bad reasons, the path to the boost library is differs between machines. I give the path via an <include> in the Jamroot file. Thus the Jamroot file has to be different on each machine. However, my code is synchronized via Subversion between the machines which poses a problem for the Jamroot file. Thus, I either can only do one-way synchronisation from one master computer and edit the Jamroot file on the other machines locally (marking the conflict as resolved after the first update after this edit) or exclude the Jamroot file from Subversion. Since I probably do modify the Jamroot file from time to time, it would be nice to include it in Subversion. Currently, I solve the problem by sticking to one-way synchronisation but if there would be another place to put the path, this would be nicer. Thanks. Markus

4 7

[BGL] Large graphs
by Sebastian Weber 09 Jul '09

09 Jul '09

Hi! I am using the BGL to represent a fractal structure which I iteratevley grow. As I intend to handle large structures I usually preallocate the required space for the final fractal in the beginning. My construction process then uses the graph object to put in new edges into the same graph object. Now, if I always use the same graph object things get messed up for large fractals. However, if I use 2 graph structures, one which represents the last and one the comming generation, everything is ok (which doubles memory requirements for nothing). I have no clue what the problem here is. For small fractals both schemes produce correct fractals, but not for large ones. I suspect that there are some really strange problems here with allocated memory going on. BTW, is there a way to preallocate the required memory for the edges of a adjacency_list graph? I do know ahaed how many edges in total and how many edges per vertex will be in the final graph, so that I could preallocate memory if it is possible. Preallocating vertices is easy... In case someone may have an idea, but needs the code I am having trouble with, no problem, just contact me. Thanks in advance, Sebastian

2 1

[graph] named vertices?
by Noah Roberts 09 Jul '09

09 Jul '09

I notice that in the changes for the newest boost that "named vertexes" is now supported in adjacency_list. I can't find anything on this feature though. I have the book, have searched the web. Only thing I find is comments in adjacency_list.hpp that maybe refers to a NamedGraph concept? I don't see that in the docs either: http://www.boost.org/doc/libs/1_39_0/libs/graph/doc/table_of_contents.html Could someone give me an overview of what this feature is and why I might use it? Probably better...point me to some place that documents it?

2 1

[boost-build][doc][boostbook][doxygen] Problems with using boost documenting tools
by Andrey Torba 09 Jul '09

09 Jul '09

I've attached simple project with documentation. There are two problems:1. doxygen generates documentation with full paths to headers <D:/c++/my_project/include/my_project/h1.hpp> instead of <my_project/h1.hpp> As you can see in attachment, i configure doxygen by defining STRIP_FROM... directives, where $(TOP)/include = D:/c++/project/include: <doxygen:param>STRIP_FROM_PATH=$(TOP)/include <doxygen:param>STRIP_FROM_INC_PATH=$(TOP)/include TOP variable i define in Jamroot as: path-constant TOP : . ; What do i do wrong? 2. Paths to images looks like <img src="../../doc/html/images/next.png" alt="Next">. Path goes up by two directories and then down, it seem through the Jamroot I need simple <img src="images/next.png" alt="Next"> How to generate forward relative paths? -- Regards, Andrey

1 0

write_graphviz requires not only VertexListGraph, but also EdgeListGraph
by Richard Ulrich 09 Jul '09

09 Jul '09

Hi everybody, this is my first post to the boost mailing list. I'm using boost_1_39 I wanted to use write_graphviz today with my custom graph adapter that implements VertexListGraph as well as IncidenceGraph. The documentation states, that write_graphviz only requires a VertexListGraph. But inside, it uses an edge_iterator, and calls edges(g), both of which belong to the EdgeListGraph. Am I right here, or did I miss something? If yes, should I implement a specialization that only calls out_edges() for every vertex, and thus a VertexListGraph would be sufficient? With kind regards Richard

3 2

Null shared pointer confusion
by Carl Hetherington 09 Jul '09

09 Jul '09

Hi, In the following program... #include <boost/shared_ptr.hpp> #include <boost/weak_ptr.hpp> class A {}; int main () { boost::shared_ptr<A> x; // A: bad_weak_ptr thrown // boost::shared_ptr<A> x ((A *) 0); // B: works boost::weak_ptr<A> y (x); boost::shared_ptr<A> z (y); } ... I observe that with line A included (but not line B), a bad_weak_ptr is thrown by the line which declares z. With line B included (but not line A), all is well. >From looking at the boost source, it seems that line A results in a shared_ptr to nothing (use_count() == 0), and line B results in a shared_ptr to 0 (use_count() == 1). I can work around this, I'm sure. Can anyone clarify my muddled thinking and explain why boost is behaving correctly in this situation (if indeed it is!) Many thanks Carl

2 1

[serialization] 1.34.1 -> 1.35 vector bug
by Josh Kelley 08 Jul '09

08 Jul '09

I'm upgrading from C++Builder 2007 with Boost 1.34.1 to C++Builder 2009 with Boost 1.35. (I realize that this is a few versions behind, but C++Builder compatibility seems problematic enough that I'm going to try sticking with 1.35, which is what the vendor officially supports. Or would people here recommend using a later version?) I'm running into problems loading XML archives containing vectors that were created by Boost 1.34.1. This appears to be the same problem that others have reported: https://svn.boost.org/trac/boost/ticket/1774 https://svn.boost.org/trac/boost/ticket/2271 http://lists.boost.org/boost-users/2009/05/48292.php If I understand those pages correctly, to work around this problem, I should be able to copy the relevant changes from Boost 1.39.0's boost/serialization/vector.hpp and boost/serialization/array.hpp, plus change BOOST_SERIALIZATION_VECTOR_VERSION from 3 to 4, and my copy of 1.35 will work both with 1.34.1 and with 1.36 and above. Is this correct? Thanks. Josh Kelley

1 0

boost::random distribution is not working within a custom class
by Oliver Fochler 08 Jul '09

08 Jul '09

Hey there, I'm having a problem with the boost::random library and I can't figure out what's going on, so maybe you guys might help me out. Here's the scenario (code below): I wrote a small class that should encapsulate a random number generator (floating point, uniform in [0,1) ) so that I ultimately can switch between different approaches (boost and non-boost) without the rest of my code ever caring. Within this class I have a boost::mt19937 object and a pointer to a boost::uniform_01<boost::mt19937&, double> as private members. Within the constructor I actually create an instance of uniform_01 via new and initialize it with the mt19937 RNG. Now within the constructor (see cout statement) the ran_boost->operator()() or (*ran_boost)() work perfectly and yield some random double between 0 and 1. However, when using the randomNumberGenerator object created in main.cpp I'm struck with segfault. Doing some backtrace it turns out that it fails with in boost::random::mersenne_twister<unsigned int, 32, 624, 397, 31, 2567483615u, 11, 7, 2636928640u, 15, 4022730752u, 18, 3346425566u>::operator() ( this=0x89485ed18949ed31) at /home/fochler/usr/include/boost/random/mersenne_twister.hpp:275 If I try to use global object ran2 (declared extern in random2.h and defined in random2.cpp) I also get a segfault, this time with in boost::random::detail::pass_through_engine<boost::random::mersenne_twister<unsigned int, 32, 624, 397, 31, 2567483615u, 11, 7, 2636928640u, 15, 4022730752u, 18, 3346425566u>&>::base (this=0x0) at /home/fochler/usr/include/boost/random/detail/pass_through_engine.hpp:42 42 base_type& base() { return helper_type::ref(_rng); } I don't really know (a) what is going on and what I've messed up and (b) whether these two errors (using the local and the global object) are connected. It would be great if somebody could help me out. Cheers, Oliver Some minimal example ----------------- random2.h ----------------- #ifndef RANDOM_NG_H #define RANDOM_NG_H #include <stdint.h> #include <boost/random.hpp> class randomNumberGenerator { public: randomNumberGenerator( const uint32_t s ); double operator()() { return ran_boost->operator()(); } private: boost::mt19937 rng_mt_boost; boost::uniform_01<boost::mt19937&, double> * ran_boost; }; extern randomNumberGenerator ran2; #endif ----------------- random2.cpp ----------------- #include <iostream> #include <boost/random.hpp> #include "random2.h" randomNumberGenerator ran2; randomNumberGenerator::randomNumberGenerator( const uint32_t s ) { boost::uniform_01<boost::mt19937&, double> * ran_boost = new boost::uniform_01<boost::mt19937&, double>( rng_mt_boost ); rng_mt_boost.seed( s ); std::cout << ran_boost->operator()() << std::endl; } ----------------- main.cpp ----------------- #include "random2.h" int main(int argc, char **argv) { randomNumberGenerator ran3( 1234567 ); double a = ran2(); double b = ran3(); return 0; }

3 4

Serialize a Tree
by 张炜 08 Jul '09

08 Jul '09

i want to serialize a self-defined tree to a binary file and vice-versa. The data structure is as follows: class Node { public: Node(); Node(int type,const string &name); ~Node(); string getNodeName(); int getNodeType(); Node *getNodeParent(); bool setNodeName(string &name); bool setNodeType(int type); bool setNodeParent(Node *parent); ............................................................. private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & type; ar & name; } int type; string name; Node *parent; public: vector<Node *> children; // children list of current node vector<AttribNode *> attribList; // attribute list of current node }; class AttribNode { public: AttribNode(); AttribNode(string attribName,int attribType,const char* value); string getAttribName(); int getAttribType(); private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & name; ar & type; ar & asciiValue; ar & binSize; } string name; int type; string asciiValue; long binSize; char *binValue; }; the difficult is how to serialize the relation between different Nodes.and the binValue. while in the memory, there has a tree.the save function is as follows: bool ConfigRegistry::saveConfigTreeToLocal() { ofstream ofs("D:\\Config.bin",ios::binary); boost::archive::binary_oarchive oa(ofs); queue<Node *> nodeQueue; nodeQueue.push((Node *)root); while(!nodeQueue.empty()) { Node * temp = nodeQueue.front(); for (int i = 0;i < temp->children.size();i++) { nodeQueue.push(temp->children.at(i)); } oa << *temp; int attribNum = temp->attribList.size(); oa << attribNum; for(int i =0;i < temp->attribList.size();i++) { oa << *(temp->attribList.at(i)); if (temp->attribList.at(i)->getAttribType() == ATTRIBUTE_TYPE_BINARY) { char * ptr = temp->attribList.at(i)->binValue; long size = temp->attribList.at(i)->binSize; oa << ptr[size]; } } int childrenNum = temp->children.size(); oa << childrenNum; nodeQueue.pop(); } return true; } bool ConfigRegistry::getConfigTreeFromLocal() { ofstream ifs("D:\\Config.bin",ios::binary); boost::archive::binary_oarchive ia(ifs); int childNum = 0; int attribNum = 0; queue<Node *> nodeQueue; root = (void *)new Node(); Node *curNode = (Node *)root; nodeQueue.push(curNode); while(!nodeQueue.empty()) { ia >> *(curNode); ia >> attribNum; while(attribNum--) { AttribNode * attribNode = new AttribNode(); ia >> *attribNode; if (attribNode->getAttribType() == ATTRIBUTE_TYPE_BINARY) { attribNode->binValue = new char[attribNode->binSize]; ia >> attribNode->binValue; } else { attribNode->binValue = NULL; attribNode->binSize = 0; } curNode->attribList.push_back(attribNode); } ia >> childNum; while (childNum--) { Node * newNode = new Node(); curNode->addChild(newNode); nodeQueue.push(newNode); } nodeQueue.pop(); curNode = nodeQueue.front(); } return true; } the saveConfigTreeToLocal() is okay. but the getConfigTreeFromLocal() is error.y? how can i serialize the self-defined tree above?

2 1