- Boost-users - lists.boost.org

serialization pointer to primitive type
by Cheok Yan Cheng 23 Aug '06

23 Aug '06

hello, i have an int pointer, which pointer to the starting address of an array. currently, i need to serialize the array elements one by one, at the same time serialize the size of the array too. i try to serialize the dynamic allocated array, just like what i did on vector, but fail. vector<int> v; ar & vector; /* no problem. */ int *i = new int[10]; ar & i; /* compile error. */ i was understand that the serialization library had no idea on the size of dynamic allocated array either during run-time or compiled time. i just want to know whether there is any better way to serialize on the above mentioned data? here is the error i get from vc++ 2003. C:\Boost\include\boost-1_33_1\boost\serialization\access.hpp(109): error C2228: left of '.serialize' must have class/struct/union type the below are my full source code. thanks! #include <fstream> // include headers that implement a archive in simple text format #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> ///////////////////////////////////////////////////////////// // gps coordinate // // illustrates serialization for a simple type // class gps_position { private: friend class boost::serialization::access; // When the class Archive corresponds to an output archive, the // & operator is defined similar to <<. Likewise, when the class Archive // is a type of input archive the & operator is defined similar to >>. template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & degrees; ar & minutes; ar & seconds; ar & data; } int degrees; int minutes; float seconds; int* data; public: gps_position(){}; gps_position(int d, int m, float s) : degrees(d), minutes(m), seconds(s) {data = new int[5];} }; int main() { // create and open a character archive for output std::ofstream ofs("filename"); // create class instance const gps_position g(35, 59, 24.567f); // save data to archive { boost::archive::text_oarchive oa(ofs); // write class instance to archive oa << g; // archive and stream closed when destructors are called } // ... some time later restore the class instance to its orginal state gps_position newg; { // create and open an archive for input std::ifstream ifs("filename", std::ios::binary); boost::archive::text_iarchive ia(ifs); // read class state from archive ia >> newg; // archive and stream closed when destructors are called } return 0; } __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Problem wih regex_search_example.cpp
by david v 23 Aug '06

23 Aug '06

Hello, I'm trying to adapt the example script regex_search_example.cpp to do what i want, that is basically search for all the patterns in a file and get their position. I'm trying to match the pattern "test" in a file that called "testfile" that looks like that: ############ file "testfile" this_is _the_file_that_contains_twice_the_word_test_test. ########### ####### In file regex_search_example.cpp i have only changed the line const char* re = "test"; ####### The output looks like that: >Processing file testfile 1 matches found class "" found at position: 56 Class is empty ?? How can i retrive all the patterns and all the positions. I thought the example was supposed to do so ?? Any help would be great. david

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Re: [Boost-users] opengl and boost::function casting problems. .
by Nat Goodspeed 23 Aug '06

23 Aug '06

________________________________________ From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of chun ping wang Sent: Tuesday, August 22, 2006 10:36 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] opengl and boost::function casting problems. . Hi, sorry for another problem... i have a simple question to ask... lets say say i have base class struct GeomObject { // draws an wire shape virtual void drawAbstract(const GLfloat& x, const GLfloat& y, const GLfloat& z) = 0; // draws a solid shape. virtual void drawSolid(const GLfloat& x, const GLfloat& y, const GLfloat& z) = 0; } Now i have bunch of stuff that inherits it.. Like class Circle, class Sphere, class Cylinder, class Cone and all of them implement drawSolid and drawAbstract (radius base assumed). I have a function call drawCircle(const std::string& r, (someBoostFunctionParam)) { Circle cir(4.0, r); // construct a circle with radius 4.0 and name r cir.someBoostFunctionParam(x, y, z); } thus if i say drawCircle("solid", &Circle::drawSolid); drawCircle("abstract", &Circle::drawAbstract); How do you do that? Or whats the best way to do it. [Nat] Since drawCircle() is specifically drawing a Circle, it would work to use an ordinary member function pointer: void drawCircle(const std::string& r, void (Circle::*drawFunction)(const GLfloat&, const GLfloat&, const GLfloat&)) { Circle cir(4.0, r); // construct a circle with radius 4.0 and name r GLfloat x = 0, y = 0, z = 0; // set values for x, y, z somehow (cir.*drawFunction)(x, y, z); } Normally I'd use typedef to tame member function pointer syntax, but it appears that you'd want a different subclass-specific member function pointer for each such drawSomething() free function.

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[Boost.Threads] MSVC memory leak detected in boost v1.33.1
by Aubrey, Jason 23 Aug '06

23 Aug '06

Hello, My questions are: 1) Is there any ETA for releasing a fix? 2) Otherwise, is there an recommended fix I can apply myself? Environment: * MSVC 8.0 * boost v1.33.1 It seems that it's a known issue that has been present for quite a while (at least since 1.30): "Perhaps this is the same leak reported by gast128 in the thread "Memory leak reported using threads library". A mutex is created in DLLMain -> on_process_enter -> init_threadmon_mutex. It seems that this mutex is never deleted and there is no comments that this is intentional. On Windows the size of the mutex is 8 bytes and it creates a CRITICAL_SECTION in its constructor - 24 bytes." I'm not concerned much by the size of the leak nor the semantics of whether it is truly a leak. My concern is that I'm receiving an alert from VS indicating "Detected memory leaks!" and regardless of how MS's detecting this, it's obviously not a good situation for me. Regards, Jason

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Converting epoch(long) to ptime in Boost.Date_Time
by gdprosch＠micron.com 23 Aug '06

23 Aug '06

I would like to convert epoch(long) time values to boost ptime and vice versa. On the surface this seems relatively easy but some of the functions needed are missing and there is an issue ensuring that the local time is properly applied. Has someone come up with an easy way to do this? I can convert to ptime like this... long epoch_in = 1140411002; // 2006-Feb-19 21:50:02 std::time_t stdtime ( epoch_in ); ptime = from_time_t( stdtime ); To convert from ptime back to epoch(long) there is no conversion provided the other way. I found some code the author supplied a few years ago here: http://lists.boost.org/MailArchives/boost-users/msg07254.php Unfortunately, the result does not correctly apply local time. The following code... std::time_t to_time_t(ptime t) { ptime start(gregorian::date(1970,1,1),time_duration(0,0,0)); return (t-start).total_seconds(); } ... produces a date with the value: 2006-Feb-20 04:50:02 and not 2006-Feb-19 21:50:02 (I am in US MST). I've played around with applying the local offset but I end up with a lot of lines of code that leave me wondering if there is a better way. It would be nice if it were simple like this (assuming local time adjustment is correctly applied)... long epoch_in = 1140411002; // 2006-Feb-19 21:50:02 ptime pt = from_epoch( epoch_in ); long epoch_out = to_epoch( pt ); Many thanks, > Greg Prosch > Micron Technology, Inc.

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opengl and boost::function casting problems. .
by chun ping wang 23 Aug '06

23 Aug '06

here is the basic header file basicgl.hpp #include <windows.h> #include <GL/gl.h> #include <GL/glu.h> #include <GL/glut.h> #include <boost/function.hpp> #include <boost/static_assert.hpp> #include <boost/type_traits.hpp> #include <boost/cast.hpp> template <class T> boost::function<void*(const T&, const T&)> getVerxFunc2() { BOOST_STATIC_ASSERT(boost::is_integral<T>::value || boost::is_floating_point<T>::value); return (boost::is_floating_point<T>::value) ? &glVertex2d : &glVertex2i; } template <class T> boost::function<void*(const T&, const T&, const T&)> getVerxFunc3() { BOOST_STATIC_ASSERT(boost::is_integral<T>::value || boost::is_floating_point<T>::value); return (boost::is_integral<T>::value) ? &glVertex3i : &glVertex3d; } template <class T> void drawDot(const T& x, const T& y) { boost::function<void(const T&, const T&)> myFunc(getVerxFunc2<T>()); glBegin(GL_POINTS); myFunc(x, y); glEnd(); glFlush(); } template <class T> void drawDot(const T& x, const T& y, const T& z) { boost::function<void(const T&, const T&, const T&)> myFunc(getVerxFunc3<T>()); glBegin(GL_POINTS); myFunc(x, y, z); glEnd(); glFlush(); } template <class T> void drawLine(const T& x1, const T& y1, const T& x2, const T& y2) { boost::function<void(const T&, const T&)> myFunc(getVerxFunc2<T>()); glBegin(GL_LINE); myFunc(x1, y1); myFunc(x2, y2); glEnd(); glFlush(); } template <class T> void drawLine(const T& x1, const T& y1, const T& x2, const T& y2, const T& z1, const T& z2) { boost::function<void(const T&, const T&, const T&)> myFunc(getVerxFunc3<T>()); glBegin(GL_LINE); myFunc(x1, y1, z1); myFunc(x2, y2, z2); glEnd(); glFlush(); } drawLine(4.1, 5.2, 3.9, 4.2); When i compile i get the following errors. 16 D:\Data\cs classes\cs450\c++\BasicGL.hpp conditional expression between distinct pointer types `void (*)(GLdouble, GLdouble)' and `void (*)(GLint, GLint)' lacks a cast 46 D:\Data\cs classes\cs450\c++\BasicGL.hpp instantiated from `void drawLine(const T&, const T&, const T&, const T&) [with T = GLdouble]' 16 D:\Data\cs classes\cs450\c++\BasicGL.hpp invalid conversion from `void (*)(GLdouble, GLdouble)' to `void*' 16 D:\Data\cs classes\cs450\c++\BasicGL.hpp invalid conversion from `void (*)(GLint, GLint)' to `void*' 85 D:\Data\Devcpp\include\boost_1_33_1\boost\function\function_template.hpp ISO C++ forbids casting between pointer-to-function and pointer-to-object Is there a nice work around this? Thanks.

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(no subject)
by Juan Ramos 23 Aug '06

23 Aug '06

Hi everybody, I'm using VC++ .NET 2003 and when compile a file with connected_components.hpp I get the following compile error: Fatal error C1001: INTERNAL COMPILER ERROR (compiler file 'msc1.cpp', line 2844) Please choose the Technical Support command on the Visual C++ What can I do to fix this error? Thanks for your help Juan

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compile error under GCC 3.4.4, but successfully compiled by GCC 3.2.3
by sean yang 22 Aug '06

22 Aug '06

I successfully compiled my program with GCC 3.2.3 on a Linux (Red Hat Linux 3.2.3-56) box. When I tried to compile the same program with GCC 3.4.4 on a Solaris box, it gave me the following errors. Can anyone help me figure out why it is happening? #g++ -O -I./boost_1_25_1 -Wall beaconfsa.cpp ./boost_1_25_1/boost/config/compiler/gcc.hpp:57:7: warning: #warning "Unknown compiler version - please run the configu re tests and report the results" In file included from ./boost_1_25_1/boost/graph/graph_utility.hpp:42, from ./boost_1_25_1/boost/graph/detail/adjacency_list.hpp:43, from ./boost_1_25_1/boost/graph/adjacency_list.hpp:293, from beaconfsa.cpp:19: ./boost_1_25_1/boost/graph/depth_first_search.hpp: In function `void boost::depth_first_search(const VertexListGraph&, const boost::bgl_named_params<P, T, R>&)': ./boost_1_25_1/boost/graph/depth_first_search.hpp:167: error: there are no arguments to `make_dfs_visitor' that depend on a template parameter, so a declaration of `make_dfs_visitor' must be available ./boost_1_25_1/boost/graph/depth_first_search.hpp:167: error: (if you use `-fpermissive', G++ will accept your code, bu t allowing the use of an undeclared name is deprecated) In file included from ./boost_1_25_1/boost/graph/dijkstra_shortest_paths.hpp:39, from beaconfsa.cpp:22: ./boost_1_25_1/boost/pending/mutable_queue.hpp: In member function `bool boost::mutable_queue<IndexedType, RandomAccess Container, Comp, ID>::test()': ./boost_1_25_1/boost/pending/mutable_queue.hpp:131: error: `is_heap' is not a member of `std' In file included from beaconfsa.cpp:22: ./boost_1_25_1/boost/graph/dijkstra_shortest_paths.hpp: In member function `void boost::dijkstra_visitor<Visitors>::edg e_relaxed(Edge, Graph&)': ./boost_1_25_1/boost/graph/dijkstra_shortest_paths.hpp:70: error: `m_vis' undeclared (first use this function) ./boost_1_25_1/boost/graph/dijkstra_shortest_paths.hpp:70: error: (Each undeclared identifier is reported only once for each function it appears in.) ./boost_1_25_1/boost/graph/dijkstra_shortest_paths.hpp: In member function `void boost::dijkstra_visitor<Visitors>::edg e_not_relaxed(Edge, Graph&)': ./boost_1_25_1/boost/graph/dijkstra_shortest_paths.hpp:74: error: `m_vis' undeclared (first use this function) beaconfsa.cpp: In function `int transition_fsa(unsigned int*, unsigned int*)': beaconfsa.cpp:282: warning: comparison between signed and unsigned integer expressions make: *** [beaconfsa.o] Error 1 _________________________________________________________________ Windows Live Spaces is here! Its easy to create your own personal Web site. http://spaces.live.com/signup.aspx

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Re: [Boost-users] bind depending on the type
by Todd Greer 22 Aug '06

22 Aug '06

Minkoo Seo wrote: > vector< pair<string, int> > subjects; > subjects.push_back(make_pair("Math", 90)); > subjects.push_back(make_pair("English", 86)); > subjects.push_back(make_pair("Physics", 88)); > subjects.push_back(make_pair("Biology", 97)); > > long total; > total = accumulate(subjects.begin(), subjects.end(), 0, > _1 + bind(&pair<string, int>::second, _2)); > This is a simple score card application that computes the total score. > As you can see, I've used bind in calling accumulate and that > seems to be ugly. So, I modified the code as follows: Seems fine to me, but it's your code, so your opinion's the important one. > So, what I want to do is write a function get_score that successfuly > compiles and run the following: > > total = accumulate(subjects.begin(), subjects.end(), 0, get_score(_1) + > get_score(_2)); > > I've tried my best only to fail. Could anybody write get_score functions > for me? You're motivation is unclear. The usual reason to use Boost.Lambda is that you want to define all of the logic of the algorithm at the call site, rather than having auxiliary definitions elsewhere. If you're going to have some part of the algorithm get its own named definition, then it's simpler just to use a regular function or function object. Then everything is quite simple: total = accumulate(subjects.begin(), subjects.end(), 0, accumulate_scores); This assumes that accumulate_scores is something like: int accumulate_scores(int a, pair<char const*, int> const& b) { return a + b.second; } If you really do want to write "total = accumulate(subjects.begin(), subjects.end(), 0, get_score(_1) + get_score(_2));", you would need to write two get_score() overloads, one that takes a boost::lambda::placeholder1_type, and one that takes a placeholder2_type. They could return types with an overloaded addition operator that returned a boost::function of the appropriate type, or they could return types equivalent to bind expressions. Although the placeholder1_type overload would simply return its argument, the other would return a long, complex, and I think unspecified type, though I guess you could generate the type with boost::result_of. Frankly, it sounds like far too much trouble; I'd take the simple route, but it's your call. -- Todd Greer

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[BGL] How to add a vertex_descriptor in a graph property
by Manuel Yguel 22 Aug '06

22 Aug '06

Hello, I want to make tree class with the BGL and so I need to specify the root of the tree. Previously I did that by deriving a graph and adding a graph_descriptor member like the code below: typedef boost::adjacency_list< boost::listS, boost::listS, boost::directedS, int > Graph; class Tree : public Graph { public: typedef typename boost::graph_traits< Graph >::vertex_descriptor root; Tree(); }; The constructor create a Vertex then defines root equal to that first vertex. But with bundled property I wanted to know if it is possible to define the root in the graph property. In fact I tried it but I am a bit embarrassed by the cyclic problem: - graph property needs to know what a vertex_descriptor is, - graph needs to know what a graph property is, - graph defines what a vertex_descriptor is. I tried the Barton-Nackman trick but I failed. Is it a proper way to do that ? Some advices, or pointers will be really apreciated. Thanks, Manuel Yguel.

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