- Boost-users - lists.boost.org

multi_array, resize and remove a row
by gast128 29 Aug '08

29 Aug '08

Dear all, this is yet another post on multi_array. It seems possible that the multi_array's are resizable (using default construction :( ). However we have no the problem that a specific row should be removed (which is not necessarily the last row). Using the resize option it seems not possbile. Am I correct? Wkr.

2 2

[spirit2] push_back not fully understood - vc8 rejects code, why?
by Markus Werle 29 Aug '08

29 Aug '08

> Hi! Though I appreciate simple examples in the docs it is indeed helpful to have examples with fully qualified names. I am having hard times figuring out which versions of "_1", "at_c", etc. are in use. the fusion/phoenix/proto/mpl chaos is hard to keep track of. In summary: using declaratives are nice for toy examples but drive you nuts, once you #include more files and have ADL destroying the idyll of simplicity. Below is a piece of code that nearly compiles. One line has a problem: A semantic action, namely a push_back fails under vc8 and the error message is far from being helpful. So could you please be so nice and give me some hint on how to fix this. (BTW, Joel: "iter+30" directives from the spirit2 examples are assert-catched by the VC8 debugging STL, so I changed that part a little bit to first check the distance and doing iterator arithmetics afterwards. See below.) best regards, Markus ---snip--- #define BOOST_SPIRIT_DEBUG_OUT std::cerr #define BOOST_SPIRIT_DEBUG #include "Enforce.h" #include <boost/tr1/functional.hpp> #include <boost/tr1/tuple.hpp> #include <boost/mpl/assert.hpp> #include <boost/mpl/at.hpp> #include <boost/config/warning_disable.hpp> #include <boost/spirit/include/qi.hpp> #include <boost/spirit/include/phoenix_core.hpp> #include <boost/spirit/include/phoenix_operator.hpp> #include <boost/spirit/include/phoenix_fusion.hpp> #include <boost/spirit/include/phoenix_stl.hpp> #include <boost/spirit/include/phoenix_container.hpp> #include <boost/fusion/include/adapt_struct.hpp> #include <boost/variant/recursive_variant.hpp> #include <boost/foreach.hpp> #include <boost/preprocessor/repetition.hpp> #include <boost/preprocessor/arithmetic/sub.hpp> #include <boost/preprocessor/punctuation/comma_if.hpp> #include <list> #include <string> #include <vector> #include <iostream> #include <iterator> using namespace boost::spirit; using namespace boost::spirit::qi; using namespace boost::spirit::ascii; using namespace boost::spirit::arg_names; using boost::phoenix::push_back; namespace fusion = boost::fusion; namespace phoenix = boost::phoenix; namespace { //////////////////////////////////////////////////////////////////////////////// // parser traits struct parser_traits { template <typename T, int Dummy = 0> struct parser; #define PARSER_TRAITS(TYPE, PARSER_T) \ template <int Dummy> struct parser<TYPE, Dummy> \ { \ typedef PARSER_T type; \ \ static inline \ PARSER_T p() \ { \ PARSER_T result; \ return result; \ } \ } // int PARSER_TRAITS(int, int_type); // unsigned int PARSER_TRAITS(unsigned int, uint_type); // double PARSER_TRAITS(double, double_type); }; //////////////////////////////////////////////////////////////////////////////// // parser template <typename Iterator, typename Tuple> struct tuple_grammar; template <typename Iterator, typename T1, typename T2> struct tuple_grammar<Iterator, std::tr1::tuple<T1, T2> > : grammar<Iterator, std::list<std::tr1::tuple<T1, T2> >(), space_type> { typename parser_traits::parser<T1>::type p1; typename parser_traits::parser<T2>::type p2; typedef typename std::tr1::tuple<T1, T2> tuple_t; tuple_grammar() : tuple_grammar::base_type(rule_tuple_list) { using phoenix::at_c; using boost::spirit::arg_names::_1; // using boost::spirit::container::push_back; using boost::phoenix::push_back; rule_tuple = '(' >> p1[at_c<0>(_val) = _1] >> ',' >> p2[at_c<1>(_val) = _1] >> ')' ; rule_tuple_list = // COMPILER FALS ON THIS SEMANTIC ACTION - WHY? *(rule_tuple[push_back(ref(_val), _1)]) ; } rule<Iterator, tuple_t(), space_type> rule_tuple; rule<Iterator, std::list<tuple_t>(), space_type> rule_tuple_list; }; //////////////////////////////////////////////////////////////////////////////// // string_to_list_of_tuples template <typename Tuple> struct string_to_list_of_tuples; template <typename T1, typename T2> struct string_to_list_of_tuples<std::tr1::tuple<T1, T2> > { typedef std::tr1::tuple<T1, T2> tuple_t; static std::list<tuple_t> apply(std::string const & s) { std::list<tuple_t> result; typedef tuple_grammar<std::string::const_iterator, tuple_t> tuple_grammar; tuple_grammar tg; std::string::const_iterator iter = s.begin(); std::string::const_iterator end = s.end(); bool r = phrase_parse(iter, end, tg, result, space); if (r && iter == end) { std::cout << "-------------------------\n"; std::cout << "Parsing succeeded\n"; std::cout << "-------------------------\n"; } else { std::size_t dist = std::distance(iter, end); std::string::const_iterator some = dist > 30 ? iter+30 : end; std::string context(iter, some); std::cout << "-------------------------\n"; std::cout << "Parsing failed\n"; std::cout << "stopped at: \"" << context << "...\"\n"; std::cout << "-------------------------\n"; } return result; } }; } // namespace int main() { try { { typedef std::tr1::tuple<int, int> tuple_t; std::list<tuple_t> test = string_to_list_of_tuples<tuple_t>::apply (" ( 1, 2 ) ( 3, 4)(5,6)"); std::copy(test.begin(), test.end(), std::ostream_iterator<tuple_t>(std::cout, "\n")); } // { // typedef std::tr1::tuple<unsigned int, int, double> tuple_t; // std::list<tuple_t> test = // string_to_list_of_tuples<tuple_t>::apply // (" ( 1, -2 , 5.123) ( 3, 4,7.9)(5,6,8.6789)"); // std::copy(test.begin(), test.end(), // std::ostream_iterator<tuple_t>(std::cout, "\n")); // } } catch (std::exception const & e) { std::cerr << e.what() << std::endl; } }

2 3

[filesystem] Catching permissions errors?
by Allen Cronce 29 Aug '08

29 Aug '08

Hi all, I need to programmatically test for permissions errors during path iteration. I think what I need to do is catch the filesystem exception, then drill out the error code and compare it to the permission_denied error value. Here's a code fragment written under boost 1.35 that demonstrates what I'm talking about: try { // Force a permissions error on *nix machines when not running as root. // Note that this code is is for demonstration purposes only. Assume that // in the real implementation I'm doing something else here with the // filesystem that *might* throw a permissions error. boost::filesystem::path testDirPath( "/usr/local/cant_touch_this" ); create_directory(testDirPath); } catch(const boost::filesystem::filesystem_error& e) { // Check the error code to see if it's a permissions error if (boost::system::posix_error::permission_denied == e.code().value()) { std::cout << "The error code indicates a permissions error, as expected. " << std::endl; } else { std::cout << "Hmm... I didn't get a permissions error. That's wrong." << std::endl; } } Is this basically the right approach? Note that one concern I have is maintainability. A coworker wrote similar code to the above, but under boost 1.33.1. That code broke under 1.35 due to significant changes to the filesystem exceptions mechanism. I understand that there are no guarantees moving forward to new boost versions. I knew the job was dangerous when I took it ;-) But if there's anything I can do today to future-proof a little bit, that would be great. Thanks in advance for any feedback or suggestions. Best, -- Allen Cronce

1 1

[exception] RTTI
by Anteru 28 Aug '08

28 Aug '08

Hi, I just upgrade to Boost 1.36, and while I'm not using Boost::exception, it gets included somewhere (gotta investigate that). That's no problem, but as my project does not use RTTI, but Boost::exception does, I'm getting warnings that the typeid() operator is used. Happens at two lines, Q:\Boost\include\boost/exception/exception.hpp(74) : warning C4541: 'typeid' used on polymorphic type 'boost::exception' with /GR-; unpredictable behavior may result Q:\Boost\include\boost/exception/exception.hpp(81) : warning C4541: 'typeid' used on polymorphic type 'boost::exception' with /GR-; unpredictable behavior may result Is there any way to disable this? After all, I'm not using boost::exception specifically, and I don't want to enable RTTI just to get rid of the warning. I'm fine if the diagnostic message becomes garbage then, after all, one usage is just to get the name of the class (typeid(*this).name), which may even return bogus results as typeid is not required to return some meaningful name. Cheers, Anteru

7 18

Visual studio 2003 settings
by Sephiroth 28 Aug '08

28 Aug '08

Hello I'm new to boost and c++. I wanted to know where I can find the settings for Visual Studio 2003. Expecially the linking additional dependencies. Thank for the help Chris

2 1

new user with compile problems
by Brenda Orlin 28 Aug '08

28 Aug '08

I am trying to use Boost version 1.36 with Microsoft Visual Studio 2005. When I try to include the thread library, I get all kinds of compile errors. One example is: Error 1 error C2632: 'float' followed by 'float' is illegal C:\Program Files\Microsoft Visual Studio 8\VC\PlatformSDK\include\windef.h 155 This does not seem right, however, I don't know what to do about it. Please help! _________________________________________________________________ Get ideas on sharing photos from people like you. Find new ways to share. http://www.windowslive.com/explore/photogallery/posts?ocid=TXT_TAGLM_WL_Pho…

2 6

boost::reference_wrapper & polymorphism
by Robert Dailey 28 Aug '08

28 Aug '08

Does boost::reference_wrapper provide polymorphic behavior? For example, if I have a boost::reference_wrapper to a base type, and I assign a derived type to it, will the function calls be polymorphic?

2 3

[TR1] patch for tr1/detail/config_all.hpp ?
by Williams, Alan B 28 Aug '08

28 Aug '08

Hello, I'm using boost.TR1 in 1.36.0, and found that tr1/detail/config_all.hpp needs a little tweak in order to work with the PGI 7.1.4 compiler. Should I send a proposed diff or patch to this mailing list, or to some individual? Thanks, Alan

2 1

[logging] Milliseconds not logged on Windows
by Allen Cronce 28 Aug '08

28 Aug '08

Hi all, I'm using the latest boost logging library from the sandbox, in conjunction with boost 1.35.0. I'm seeing problems with millisecond strings in the log under Windows VS2005. The following formatter works fine under posix (specifically, Mac OS X): g_log_dbg()->writer().add_formatter( formatter::time("$hh:$mm.$ss. $mili ") ); Here's some sample output: 19:33.54.4196908 hello, world 19:33.54.4197788 this is so cool (but only in the debug build) 1 But the same code running under Windows always outputs a consistent, bogus millisecond value: 18:41.47.-858993460 hello, world 18:41.47.-858993460 this is so cool (but only in the debug build) 1 Looks like a sign extension problem. But I have to admit that I have not invested the time to determine whether this is a bug in the logging library proper, or a problem with the underlying boost 1.35.0 precision time and string utilities used by the logging library. Regardless I can probably live without milliseconds in my Windows logs, so I'll work around it with a platform conditional that specifies an alternate format string under Windows. Best, -- Allen Cronce

1 0

[logging] Build errors under VS2005 Unicode
by Allen Cronce 28 Aug '08

28 Aug '08

Hi all, I'm using the boost logging library from the sandbox, in conjunction with boost 1.35.0. I'm seeing problems building basic sample code under Windows VS2005 in projects where UNICODE and _UNICODE is defined. Here's an example line of problematic code: g_log_err()->writer().add_formatter( formatter::idx(), "[%] " ); Here's the error generated: --snip-- 1>c:\sources\logutils.cpp(56) : error C2664: 'void boost ::logging ::writer ::format_write < formatter_base ,destination_base ,lock_resource ,apply_format_and_write ,router_type ,formatter_array ,destination_array >::add_formatter<boost::logging::formatter::idx_t<>>(formatter,const boost::logging::char_type *)' : cannot convert parameter 2 from 'const char [5]' to 'const boost::logging::char_type *' 1> with 1> [ 1> formatter_base = boost ::logging ::formatter::base<boost::logging::default_,boost::logging::default_>, 1> destination_base = boost ::logging ::destination::base<boost::logging::default_,boost::logging::default_>, 1> lock_resource=boost::logging::lock_resource_finder::single_thread, 1> apply_format_and_write = boost ::logging ::format_and_write ::simple<boost::logging::optimize::cache_string_one_str<>>, 1> router_type=boost::logging::msg_route::simple<boost::logging::formatter::base<boost::logging::default_,boost::logging::default_>,boost::logging::destination::base<boost::logging::default_,boost::logging::default_>,boost::logging::lock_resource_finder::single_thread>, 1> formatter_array = boost ::logging ::array ::shared_ptr_holder < boost ::logging ::formatter ::base < boost ::logging ::default_,boost::logging::default_>,boost::logging::threading::mutex>, 1> destination_array = boost ::logging ::array ::shared_ptr_holder < boost ::logging ::destination ::base < boost ::logging ::default_,boost::logging::default_>,boost::logging::threading::mutex>, 1> formatter=boost::logging::formatter::idx_t<> 1> ] 1> Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast 1>c:\sources\logutils.cpp(58) : error C2440: '<function-style-cast>' : cannot convert from 'const char [19]' to 'boost::logging::formatter::time' 1> No constructor could take the source type, or constructor overload resolution was ambiguous 1>c:\sources\logutils.cpp(58) : error C2780: 'void boost ::logging ::writer ::format_write < formatter_base ,destination_base ,lock_resource ,apply_format_and_write ,router_type ,formatter_array,destination_array>::add_formatter(formatter,const boost::logging::char_type *)' : expects 2 arguments - 1 provided 1> with 1> [ 1> formatter_base = boost ::logging ::formatter::base<boost::logging::default_,boost::logging::default_>, 1> destination_base = boost ::logging ::destination::base<boost::logging::default_,boost::logging::default_>, 1> lock_resource=boost::logging::lock_resource_finder::single_thread, 1> apply_format_and_write = boost ::logging ::format_and_write ::simple<boost::logging::optimize::cache_string_one_str<>>, 1> router_type=boost::logging::msg_route::simple<boost::logging::formatter::base<boost::logging::default_,boost::logging::default_>,boost::logging::destination::base<boost::logging::default_,boost::logging::default_>,boost::logging::lock_resource_finder::single_thread>, 1> formatter_array = boost ::logging ::array ::shared_ptr_holder < boost ::logging ::formatter ::base < boost ::logging ::default_,boost::logging::default_>,boost::logging::threading::mutex>, 1> destination_array = boost ::logging ::array ::shared_ptr_holder < boost ::logging ::destination ::base < boost ::logging ::default_,boost::logging::default_>,boost::logging::threading::mutex> 1> ] 1> c:\sources\thirdpartylibs\installedwin32\individual\boost \include\boost\logging\detail\format_write_detail.hpp(232) : see declaration of 'boost ::logging ::writer ::format_write < formatter_base ,destination_base ,lock_resource ,apply_format_and_write ,router_type,formatter_array,destination_array>::add_formatter' 1> with 1> [ 1> formatter_base = boost ::logging ::formatter::base<boost::logging::default_,boost::logging::default_>, 1> destination_base = boost ::logging ::destination::base<boost::logging::default_,boost::logging::default_>, 1> lock_resource=boost::logging::lock_resource_finder::single_thread, 1> apply_format_and_write = boost ::logging ::format_and_write ::simple<boost::logging::optimize::cache_string_one_str<>>, 1> router_type=boost::logging::msg_route::simple<boost::logging::formatter::base<boost::logging::default_,boost::logging::default_>,boost::logging::destination::base<boost::logging::default_,boost::logging::default_>,boost::logging::lock_resource_finder::single_thread>, 1> formatter_array = boost ::logging ::array ::shared_ptr_holder < boost ::logging ::formatter ::base < boost ::logging ::default_,boost::logging::default_>,boost::logging::threading::mutex>, 1> destination_array = boost ::logging ::array ::shared_ptr_holder < boost ::logging ::destination ::base < boost ::logging ::default_,boost::logging::default_>,boost::logging::threading::mutex> 1> ] --snip-- According to the documentation, the library should automatically sense the UNICODE definition under Windows and do the right thing. But that doesn't seem to work right. I played around with trying to get this to work, but found that I had to always pass non-wide strings to the various interfaces. Ultimately I gave up and disabled the logging of wide character strings by defining the following: #define BOOST_LOG_DONOT_USE_WCHAR_T For my particular needs, logging 8 bit characters probably makes more sense anyway. But it's somewhat bothersome that the logging library did not work out of the box as documented. Sorry in advance if I missed some other configuration or nuance needed to get the logging library to work under UNICODE. Best, -- Allen Cronce

1 0