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generating docu fails
by Oliver Kowalke 05 Dec '12

05 Dec '12

Hello, 'quickbook context.qbk' generates context.xml but generating the html via bjam fails: /boost_1_52_0/tools/build/v2/build/generators.jam:1085: in ensure-type from module generators error: target { context.qbk. } has no type /boost_1_52_0/tools/build/v2/build/generators.jam:1319: in generators.construct from module generators /boost_1_52_0/tools/build/v2/build/targets.jam:1495: in construct from module object(typed-target)@927 /boost_1_52_0/tools/build/v2/build/targets.jam:1298: in object(typed-target)(a)927.generate from module object(typed-target)@927 /boost_1_52_0/tools/build/v2/build/targets.jam:732: in generate-really from module object(main-target)@958 /boost_1_52_0/tools/build/v2/build/targets.jam:704: in object(main-target)(a)958.generate from module object(main-target)@958 /boost_1_52_0/tools/build/v2/build/targets.jam:258: in object(project-target)(a)926.generate from module object(project-target)@926 /boost_1_52_0/tools/build/v2/build-system.jam:736: in load from module build-system /boost_1_52_0/tools/build/v2/kernel/modules.jam:283: in import from module modules /boost_1_52_0/tools/build/v2/kernel/bootstrap.jam:142: in boost-build from module /boost_1_52_0/boost-build.jam:17: in module scope from module how can it be fixed? Oliver

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[mpl] [bimap] BOOST_MPL_LIMIT_METAFUNCTION_ARITY issue on g++ 4.6.3 and boost 1.50
by Adam Lach 05 Dec '12

05 Dec '12

Hi, I have already asked for help on Boost.users, but with no luck, see here <http://boost.2283326.n4.nabble.com/Problems-in-boost-mpl-aux-template-arity…> . Since then I have managed to reproduce this problem in a simpler case: #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_METAFUNCTION_ARITY 10 #include <boost/mpl/inherit.hpp> #include <boost/bimap.hpp> struct S0 {}; struct S1 {}; struct S2 {}; struct S3 {}; struct S4 {}; struct S5 {}; template<typename T0, typename T1, typename T2, typename T3, typename T4, typename T5> struct example : boost::mpl::inherit<T0,T1,T2,T3,T4,T5> {}; int main() { example<S0,S1,S2,S3,S4,S5> pasta; return 0; } The weird thing is that it occurs only if bimap.hpp is included. Please help. Thank you in advance, Adam Lach -- View this message in context: http://boost.2283326.n4.nabble.com/boost-mpl-bimap-BOOST-MPL-LIMIT-METAFUNC… Sent from the Boost - Dev mailing list archive at Nabble.com.

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Looking for someone with MSVC 8 or MSVC 9
by Marshall Clow 04 Dec '12

04 Dec '12

One of the string_ref tests is failing on these two compilers - neither of which I have access to. I would appreciate some help debugging this failure [ FWIW, the same tests pass on MSVC 10 and 11 ] Thanks in advance! -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

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Re: [boost] [iterator] UB when implicitly using default constructed counting_iterator<unsigned>
by Peter Sommerlad 04 Dec '12

04 Dec '12

Hi Jeff, On 04.12.2012, at 18:59, Jeffrey Lee Hellrung, Jr. wrote: > On Sun, Dec 2, 2012 at 8:41 AM, Peter Sommerlad <peter.sommerlad(a)hsr.ch>wrote: > just consider the following small program: >> >> #include <iostream> >> #include <boost/iterator/counting_iterator.hpp> >> >> int main(){ >> std::cout << unsigned() << '\n'; // zero >> std::cout << *boost::counting_iterator<unsigned>()<< '\n';// >> undefined behavior >> } >> > > Not quite UB :) It just outputs an undefined value. It won't blow up the > moon, for example. That is not true. According to the standard reading an uninitialized value incurs undefined behavior. While in practice your computer might not explode, it is inherently unsafe and unportable to rely on something like this. See below. Therefore my concerns (I am a regular attendant of the standard committee meetings, so I can check with the real experts about that, if you doubt). 4.1 Lvalue-to-rvalue conversion [conv.lval] • 1 A glvalue (3.10) of a non-function, non-array type T can be converted to a prvalue.53 If T is an incomplete type, a program that necessitates this conversion is ill-formed. If the object to which the glvalue refers is not an object of type T and is not an object of a type derived from T, or if the object is uninitialized, a program that necessitates this conversion has undefined behavior. If T is a non-class type, the type of the prvalue is the cv-unqualified version of T. Otherwise, the type of the prvalue is T.54 > > I understand your concerns, I think, but I believe it's somewhat misguided. > I believe your proposal could do at least as much to mask errors as it will > to find errors. Indeed, your original example would've silently worked as > expected (with the present implementation of filter_iterator, anyway) with > your proposed change, even though it's (still) incorrect usage. I still believe it is much better for a library to not incur silently undefined behavior, but to provide a defined default value, even if it is unusable in general, but detectable. if I would have used 0 as the start iterator in the original example instead of 1 I would have seen something is wrong with my unit tests. However, the undefined behavior didn't help me detecting it. Regards Peter. -- Prof. Peter Sommerlad Institut für Software: Bessere Software - Einfach, Schneller! HSR Hochschule für Technik Rapperswil Oberseestr 10, Postfach 1475, CH-8640 Rapperswil http://ifs.hsr.ch http://cute-test.com http://linticator.com http://includator.com tel:+41 55 222 49 84 == mobile:+41 79 432 23 32 fax:+41 55 222 46 29 == mailto:peter.sommerlad@hsr.ch

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[BGL] status of maximum adjacency search
by Fernando Vilas 03 Dec '12

03 Dec '12

Hi, What remains to get ticket 6780 ready to commit? -- Thanks, Fernando Vilas fvilas(a)iname.com

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[functional/hash] error: more than one instance of overloaded function "fpclassify" matches the argument list:
by Vicente J. Botet Escriba 02 Dec '12

02 Dec '12

Hi, there is a compile error that making fail all the tests in this tester. Could someone take care of it? Best, Vicente Test output: lazy piranha fedora 17 64 C++11 - thread - async__async_p / intel-linux-13.0.1 Rev 81655 / Sat, 1 Dec 2012 18:49:57 +0000 *Report Time: *Sun, 2 Dec 2012 12:54:01 +0000 Compile [2012-12-02 03:35:40 UTC]: fail "/opt/intel/bin/icpc" -c -xc++ -std=c++11 -O0 -g -w2 -inline-level=0 -pthread -fPIC -wd1418 -wd193,304,383,444 -wd2415 -wd593,981 -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED -DBOOST_THREAD_USE_DLL=1 -I".." -c -o "/home/michael/boost_testing/results/boost/bin.v2/libs/thread/test/async__async_p.test/intel-linux-13.0.1/debug/threading-multi/sync/futures/async/async_pass.o" "../libs/thread/test/sync/futures/async/async_pass.cpp" ../boost/functional/hash/detail/hash_float.hpp(214): error: more than one instance of overloaded function "fpclassify" matches the argument list: function "fpclassify(double)" function "std::fpclassify(double)" argument types are: (double) switch (fpclassify(v)) { ^ detected during: instantiation of "std::size_t={unsigned long} boost::hash_detail::float_hash_value(T) [with T=double]" at line 312 of "../boost/functional/hash/hash.hpp" instantiation of "boost::hash_detail::float_numbers<T>::type boost::hash_value(T) [with T=double]" at line 413 of "../boost/functional/hash/hash.hpp" compilation aborted for ../libs/thread/test/sync/futures/async/async_pass.cpp (code 2) TinyUrl <javascript:make_tinyurl()>

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Fwd: [iterator] UB when implicitly using default constructed counting_iterator<unsigned>
by Jeffrey Lee Hellrung, Jr. 01 Dec '12

01 Dec '12

[Sorry, forgot to reply-all.] ---------- Forwarded message ---------- From: Jeffrey Lee Hellrung, Jr. <jeffrey.hellrung(a)gmail.com> Date: Fri, Nov 30, 2012 at 5:53 PM Subject: Re: [boost][iterator] UB when implicitly using default constructed counting_iterator<unsigned> To: Peter Sommerlad <peter.sommerlad(a)hsr.ch> On Fri, Nov 30, 2012 at 1:14 AM, Peter Sommerlad <peter.sommerlad(a)hsr.ch>wrote: > Hi Jeffrey, hi all, > > I believe the usability of counting iterator could be improved, by > value-initializing its Iterator type in the default constructor, because > integral types won't be initialized by its default constructor. This can > lead to hard to recognize user errors, e.g., when wrapping such a counting > iterator with a filter iterator. > > counting_iterator is special in that sense, because to my understanding it > is intended to adapt integral types to become iterators. And a default > initialized scalar type, isn't. > "isn't"...what, exactly? > I suggest a one line change: > > counting_iterator() { } > > should become > > counting_iterator() : super_t(Incrementable()) { } > Well, that's one thing you can do... > The following example program shows the interesting UB, because the 3rd > argument of make_filter_iterator, default constructs a > counting_iterator<unsigned>(). > > Any thoughts? Objections? Teachings... > > Regards > Peter. > > =====>8 > #include <iostream> > #include <boost/iterator/filter_iterator.hpp> > #include <boost/iterator/counting_iterator.hpp> > #include <algorithm> > #include <iterator> > #include <functional> > > struct is_prime{ > bool operator()(unsigned int val) const { > if (val < 2) return false; > using std::placeholders::_1; > auto ce=boost::make_counting_iterator(val); > return ce==std::find_if_not(boost::make_counting_iterator(2u),ce, > > bind(std::modulus<unsigned>{},val,_1)); > } > }; > int main(){ > > std::copy_n(boost::make_filter_iterator(is_prime{},boost::make_counting_iterator(1u) > // if the following line is omitted we have undefined behavior, > because of uninitialized unsigned value > // > ,boost::make_counting_iterator(std::numeric_limits<unsigned>::max()) // > must be different from above value > ),40,std::ostream_iterator<unsigned>{std::cout,", > "}); > } > > =====8< The thing that bothers me about this is that a default-constructed iterator frequently is an end iterator; indeed, that's the assumption that filter_iterator appears to be making if no end iterator is supplied. So if the default-constructed iterator is not an end iterator, and you're wrapping it with a filter_iterator and not explicitly supplying the end, I'd say you're automatically asking for trouble, regardless of whether you're using a counting_iterator or not. On the other hand, I'm not sure what a sensible default value is for counting_iterator< [integral type] >; 0 is almost never going to be the end value; std::numeric_limits<>::max() might be a better choice, but really the end value is context-dependent. I'm not opposed to giving defined behavior to a default constructed counting_iterator< [integral type] >, I'm just not sure what that defined behavior should be. Maybe I'm over-analyzing it... - Jeff

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Re: [boost] [locale] [filesystem] Windows local 8 bit encoding
by Thiel, Bjoern 30 Nov '12

30 Nov '12

Hi Artyom, > Currently win32 API supports only UTF-8 encodings, so you need to one of: > > - compile with ICU > - select std backend (because the default without ICU on windows is win32) > - disable win32 backend (in build options) so only std backend would be used. But you should note that under > Windows only MSVC has std backend support, for gcc and ANSI encodings you need ICU, Is there reason why win32 and std backend behave differently here? Using std locale get_system_locale() method works for code pages of the form 'windows-XXX'. Others e.g. 'Shift_JIS' should fail. And if you want the CURRENT locale on Microsoft Windows, I simply can't see how to get that. But why not add generator.generate( void ) giving exactly that. Best regards Bjoern.

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[mpl] Determining when a type is a placeholder expression
by Edward Diener 30 Nov '12

30 Nov '12

Is there any way to determine when a type is an MPL placeholder expression ? I can determine whether a type is a metafunction class ( it has a class template called 'apply' ), but I can't think of any sure way to determine whether or not a type is a placeholder expression. Ideally if a type in one of my templates is an MPL lambda expression ( its either a metafunction class or placeholder expression ) I want to invoke it with some compile-time data, otherwise I want to do something else with that type. Of course a less elegant solution is to have another template boost::mpl::bool_ parameter telling which it is but I was hoping to avoid it if I can figure it out myself.

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i am not able to login in to the Trac
by Nilesh Raghuvanshi 29 Nov '12

29 Nov '12

Hi, please help me out with this. how to get to know my username and password. Thanks & regards Nileshkumar K R

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