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Is 'double' a signed type? (boost type traits)
by cdmh 21 Dec '12

21 Dec '12

Hi, I have found some surprising behaviour with boost type traits using MSVC2012 (v11). I used boost::is_signed<T>::value where T is double and it evaluates to false, but I expected true as double can hold negative numbers. More surprisingly, I found that, for double, is_unsigned is not the inverse of is_signed, and hence this static assert produces a compiler error. BOOST_STATIC_ASSERT(boost::is_unsigned<double>::value == !boost::is_signed<double>::value); I am missing a rationale for this, or it is a bug? Thanks -- Craig -- View this message in context: http://boost.2283326.n4.nabble.com/Is-double-a-signed-type-boost-type-trait… Sent from the Boost - Users mailing list archive at Nabble.com.

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boost::bind for C function
by Philipp Kraus 21 Dec '12

21 Dec '12

Hello, I have got a a C library function call, which defines a function: typedef int (*CFunction) (State* K); So I would like to use boost::bind / boost::function to create the binding to a class method: boost::function<CFunction>( boost::bind(&MyClass::myMethod, this) ) so that I can use the class method with the CFunction signature. I would like to call a class method with the object context like a C function. Can anybody help me to create a correct binding? Thanks Phil

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[Property Message] How to store variant in property tree
by Elizabeta 21 Dec '12

21 Dec '12

Hi I want to store variant object in my property tree. The variant for now will have only 3dPoint object, but it should vary multiple types in future. I tried the following code , and I am getting compiler errors. I know that maybe I need to write some kind of translation code for this to work,but don't know how to do that exactly and having hard time to grasp the concept. So how can I do this if possibly at all ? A code example would be great class 3dPoint { public: 3dPoint(double,double,double); double x; double y; double z; }; typedef boost::variant<ON_3dPoint> MyVariant; using namespace boost::property_tree; typedef basic_ptree<std::string,MyVariant> my_ptree; my_ptree pt; MyVariant point_variant = 3dPoint(1,2,3); pt.put("point",point_variant); MyVariant point_variant2 = pt.get("point"); boost::property_tree::xml_writer_settings<char> settings('\t', 1); write_xml("C:\\property.xml",pt,std::locale(),settings);

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Symbol 'is_arithmetic' could not be resolved, Symbol 'is_const' could not be resolved, Symbol 'value' could not be resolved
by Tanya 21 Dec '12

21 Dec '12

Dear Boost Users, I have a code with: BOOST_STATIC_ASSERT(::boost::is_arithmetic<T>::value); and it gives error message: - Symbol 'is_arithmetic' could not be resolved - Symbol 'value' could not be resolved and, BOOST_STATIC_ASSERT(!::boost::is_const<T>::value); and it gives error message: - Symbol 'value' could not be resolved - Symbol 'is_const' could not be resolved what should I include to get rid of these error message? I use: - Boost 1.46.1. - Compiler : Mingw with gcc - IDE: Eclipse Indigo Indigo Service Release 2 - Windows XP Professional SP 3, v. 2002 Any help, hints, would be highly appreciated! Best Regards, Tanya

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BOOST::ASIO load key.pem with passphrase
by Alvaro Leiva 21 Dec '12

21 Dec '12

Currently I'm working with this: ... ctx.use_certificate_chain_file("./C/cert.pem"); ctx.use_private_key_file("./C/key.pem", boost::asio::ssl::context::pem); ctx.load_verify_file("./C/ca.pem");... So far everything works perfect, but what I really need to do is load the same key.pem but with a passphrase, Looking at asio docs found ssl::context::set_password_callback<http://www.boost.org/doc/libs/1_52_0/doc/html/boost_asio/reference/ssl__con…> wich according to the info calls SSL_CTX_set_default_passwd_cb<http://www.openssl.org/docs/ssl/SSL_CTX_set_default_passwd_cb.html> and allows to handle encrypted PEM files, please remember that I'm much more familiarized with high level languages like python, so c++ is not my forte any help is appreciated, Thank you ! -- Alvaro Leiva

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Link problem on Mac - tag_original_exception_type
by John M. Dlugosz 20 Dec '12

20 Dec '12

I'm getting a linker error when I build my program on the Mac, that __ZTSPN5boost27tag_original_exception_typeE is duplicate defined. This is the only symbol that is giving this problem. Any ideas what's special about that one, or what it might be?

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[preprocessor]:issues with expansion.
by Littlefield, Tyler 20 Dec '12

20 Dec '12

hello all: I have the following code: #define REGISTER_MODULE(module)(\ #ifdef BOOST_PP_EQUAL(BOOST_PP_LIST_SIZE(MODULES), 0)\ //there are currently no modules in the list. #define MODULES((module), BOOST_PP_NIL) #else BOOST_PP_LIST_APPEND(MODULES, module)\ #endif ) I am somewhat of a newb at preprocessor magic, so any advice would be useful. For whatever reason this translates out to 'module)' when I try to compile it with -E -P. The idea is that it will add to the modules list (assuming the modules list exists) the module to be registered, which should just be a type. Thanks, -- Take care, Ty http://tds-solutions.net The aspen project: a barebones light-weight mud engine: http://code.google.com/p/aspenmud He that will not reason is a bigot; he that cannot reason is a fool; he that dares not reason is a slave.

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C++ gurus - really dumb question regarding partial speciallization.
by Robert Ramey 20 Dec '12

20 Dec '12

I've got the following code which fails to compile. I'm really stumped by this. I've consulted the standard document on the subject and for the life of me I can't see anything wrong with it. It fails with the same message on vc 9.0 as well as gcc 4.5.3. It's so simple it can't be a compiler issue. I appoligize in advance for spaming the list here - but I'm really, really stuck. Robert Ramey // primary template template< class T, int MIN, int MAX > struct safe_range1{}; // instantiate primary as a test safe_range1<int, 0, 1> t1; // partial specialization # 1 template< int MIN, int MAX > struct safe_range1<int, MIN, MAX>{}; // instantiate partial specialization - what the ??? // fails with "too few template parameters" !!! safe_range1<0, 1> t2; // partial specialization # 2 template<class T> struct safe_range1<T, 0, 1> {}; // also fails with "too few template parameters" !!! safe_range1<int> t3;

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[polygon] bug with self intersecting polygons ?
by Renaud Lepère 20 Dec '12

20 Dec '12

Hello, I'm trying to remove some internal loops on polygons as illustrated in the following drawing : +---------------+ +---------------+ | | / | / | |\ / | / | | X | X | |/ \ | \ | / \ | \ +----->---------+ +----->---------+ I need strong numerical robustness, i am using boost polyon with integer coordinates (using boost-1.52 + win32). It works on a lot of samples but i encounter a bug on an example. I reduced to the following sample which is roughtly a triangle (IMHO it should return a triangle). #include <boost/polygon/polygon.hpp> #include <vector> #include <iostream> using namespace boost::polygon; using namespace std; typedef point_data< int > point; typedef vector< point > points; typedef polygon_set_data< int > polygon_set; typedef polygon_with_holes_data< int > polygon_with_holes; typedef vector< polygon_with_holes > polygons_with_holes; /* * A triangle A, B, C with some nearly aligned points between B and C. * * A * + * |\ * | \ * | \ * | \ * | \ * | \ * | \ * | \ * | /-+ C * B +--- */ polygon_with_holes MakeRawPolygon() { points ps; ps.push_back(point(-181928106,288346744)); // A ps.push_back(point(-15311797,-289428209)); // B ps.push_back(point(56093690,-270295166)); ps.push_back(point(24502047,-278760121)); ps.push_back(point(57745146,-269852659)); ps.push_back(point(56791908,-270108078)); ps.push_back(point(-14613579,-289241121)); ps.push_back(point(82923673,-263106094)); // C polygon_with_holes poly; set_points(poly, ps.begin(), ps.end()); return poly; } int main() { polygon_with_holes polygon(MakeRawPolygon()); polygon_set ps; ps.insert(polygon); // first unrool polygons_with_holes unrolled_polygons; ps.get(unrolled_polygons); if (unrolled_polygons.size() == 0u) { std::cout << "error" << endl; } } Is there something wrong in my code ? or is this a real bug. Thanks for your help and time. Renaud

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[Boost.Test] Command line arguments
by Noah Roberts 20 Dec '12

20 Dec '12

I want to add command line arguments to my unit test but I cannot find how to do so. I found the place to get argc and argv from the main suite, but when I pass in arguments that the framework doesn't already know about I get heap corruption. Is there a way to instruct the unit test framework about additional command line arguments you want to process in your test?

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