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[fusion] adapt std::tuple to be a fusion sequence?
by Nathan Ridge 19 Jul '11

19 Jul '11

Hello, Is it possible to adapt std::tuple to be a fusion sequence? I'm thinking it may be possible to do it for a specific number of elements using BOOST_FUSION_ADAPT_TPL_ADT, but I haven't tried. Is there some functionality like this already in fusion? Thanks, Nate.

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Boost::Asio SSL Handshake - Payload in TDS package
by Andi Clemens 19 Jul '11

19 Jul '11

Hi, I need to parse TDS packages that contain SSL as their payload. For example the TDS package type 0x12 (PreLogin) will have the SSL handshake as its payload. Can I extract this payload and somehow tell Boost::Asio to use this data for an SSL handshake (async_handshake)? Andi

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What result_type ? And why?
by John M. Dlugosz 19 Jul '11

19 Jul '11

I wrote the following functor: struct ASCII_lower { template< typename CharT > CharT operator() (const CharT& ch) const { if (ch >= 'A' && ch <= 'Z') return ch+0x20; return ch; // unchanged } }; and when I used it to create a transformed_range, I get an error that it doesn't find result_type in ASCII_lower. Since the return type depends on the argument, how could I declare a result_type? And why do I need it? Lambda functions don't have it, and I thought it was fairly old fashioned and optional for helping figure out the result type if necessary.

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invalid conversion from 'bool
by Eric Lin 19 Jul '11

19 Jul '11

Dear Advanced c/g++ on boost programers: I have copied and testd a simple (Copy a file with Boost) program from page 372, Example10-10, book(C++ cookbook) but I got compile error ----------------------------- eric@eric-laptop:~/cppcookbook/ch10$ g++ Example10-10.cpp Example10-10.cpp: In function ‘int main(int, char**)’: Example10-10.cpp:17:47: error: invalid conversion from ‘bool (*)(const std::string&)’ to ‘boost::enable_if_c<true, void>::type*’ Example10-10.cpp:17:47: error: initializing argument 2 of ‘boost::filesystem3::path::path(const Source&, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type> >::type*) [with Source = char*, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type> >::type = void]’ Example10-10.cpp:18:47: error: invalid conversion from ‘bool (*)(const std::string&)’ to ‘boost::enable_if_c<true, void>::type*’ Example10-10.cpp:18:47: error: initializing argument 2 of ‘boost::filesystem3::path::path(const Source&, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type> >::type*) [with Source = char*, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type> >::type = void]’ Example10-10.cpp:18:48: error: expected ‘)’ before ‘;’ token ----------------------------- This is my program, you can download and test by your self from http://examples.oreilly.com/9780596007614/ ----------------------------------------------------- // Example 10-10. Copying a file with Boost #include <iostream> #include <string> #include <boost/filesystem/operations.hpp> #include <boost/filesystem/fstream.hpp> #include <boost/filesystem/path.hpp> using namespace std; using namespace boost::filesystem; int main(int argc, char** argv) { // Parameter checking... try { // Turn the args into absolute paths using native formatting path src = complete(path(argv[1], native)); path dst = complete(path(argv[2], native); copy_file(src, dst); } catch (exception& e) { cerr << e.what() << endl; } return(EXIT_SUCCESS); } ---------------------------------------------------------------------------- I ever check around web, there is some suggestion ask me to get rid native, but in my test/system, it only generate more errors. my boost version probably is 1.46.1 and I am on g++ 4.5.2 and Ubuntu10.04/linuxKernel2.6.35-25 Need and thanks your help a lot in advance, Eric

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Boost.Iterator and future standards?
by John M. Dlugosz 19 Jul '11

19 Jul '11

The documentation for Boost.Iterator says "Both iterator_facade and iterator_adaptor as well as many of the specialized adaptors <http://www.boost.org/doc/libs/1_46_1/libs/iterator/doc/index.html#specializ…> mentioned below have been proposed for standardization, and accepted into the first C++ technical report" But I don't see that in <http://www.boost.org/doc/libs/1_46_1/doc/html/boost_tr1.html> or notice anything concerning them in other TR1 writeups. Can someone clarify the situation?

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[icl] possible bug for set difference
by Thomas Taylor 18 Jul '11

18 Jul '11

Hi! First let me express my happiness for having this library, as it makes a lot of my programming tasks much easier! While using it I think I discovered a bug for interval_set, when a difference is calculated; please find a test case attached. This was compiled against recent svn (r73190). cheers, Thomas

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Boost.Log
by asif saeed 18 Jul '11

18 Jul '11

Hi, What is the status of Boost.Log? Is operating system log (e.g. Windows Event Log, Unix's Syslog) supported? If logging via OS is not supported then how it can be implemented, would you please give me a link or some examples/guidelines? Best, Asif

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[Rational] "r.den > zero" assertion failure
by Pierre Cagne 18 Jul '11

18 Jul '11

Hi, I'm having a weird dynamic failure using Boost.Rational. Using some rationals and doing a calculus, i'm ending with a rational with a negative denominator, and so unusable for comparison (hence the r.den > 0 assertion failure during the execution). More precisely, here is a piece of code : (with typedef boost::rational<mpz_class> rat) std::cout << xa << " " << ya << " " << xb << " " << yb << " " << xc << " " << yc << " " << xd << " " << yd << std::endl; // determinant rat delta = (xb - xa)*(yc - yd) - (yb - ya)*(xc - xd); std::cout << "Delta : " << delta << std::endl; /* ... some comparisons on delta ...*/ For the following result : 0/1 1/4 1/2 0/1 0/1 0/1 1/1 0/1 Delta : 1/-4 Assertion failed: (r.den > zero), function operator<, file /usr/local/include/boost/rational.hpp, line 388. How does it come that Boost does not maintain the assertion correct ? I precise that the same code with the type boost::rational<int> does not produce the failure. Thankfully. P.S. : i'm new on this mailing-list ; does my message match with the common pattern of this list ? -- Pierre Cagne pierre.cagne(a)gmail.com

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in the makefile, how to find/configure boost lib path and include path on different machines?
by deqiang sun 17 Jul '11

17 Jul '11

Hi all, I am writing a small program depending on boost libs. However, my work environment unfortunately includes many computers with boost installed on different locations. In such scenario, how should I write the makefile to make it correctly include headers and link to libs? Thanks very much, DSUN

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exception problem with boost::filesystem under cygwin
by Kraus Philipp 17 Jul '11

17 Jul '11

Hello, I'm using boost::filesystem within my project (boost 1.47.0). I have compiled the boost under cygwin with bjam. I have some problems with exception throws / catches: The following example shows the problem: #include <stdexcept> #include <boost/filesystem.hpp> int main(int argc, char* argv[]) { throw std::runtime_error("xxx"); return 0; } If I compile this code under Cygwin and link cygboost_filesystem and cygboost_system, the programs terminates with this messages: terminate called after throwing an instance of 'std::runtime_error' terminate called recursively If I remove the boost/filesystem include the program produce the correct message: terminate called after throwing an instance of 'std::runtime_error' what(): xxx If I change the program to: int main(int argc, char* argv[]) { try { throw std::runtime_error("xxx"); } catch (...) {} return 0; } the program breaks down with the filesystem include: terminate called after throwing an instance of 'std::runtime_error' terminate called recursively without the include always works fine. Can anyone help me to solve the problem? Thanks a lot Phil

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