September 2006 - Boost-users

[function] How do you bind two boost::function objects together?
by Jason House 01 Oct '06

01 Oct '06

I'm trying to convert the input argument to a function object using a small helper function object. The code below looks relatively simple, but it doesn't seem to compile. Any ideas what could be wrong? template<typename inputType, typename outputType> boost::function<outputType (int)> convert(boost::function<outputType (inputType)> &object_to_convert){ boost::function<intputType (int)> input_converter(...); // The following fails to compile boost::function<outputType (int)> converted_function (boost::lambda::bind(object_to_convert, input_converter)); return converted_function }

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[Property Tree] Latest version and CVS
by Chris Weed 01 Oct '06

01 Oct '06

Hi, I am interested in using the new Property Tree library, and I was wondering where I can get the latest version. Chris

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[Date_Time]A better algorithm for from_undelimited_string(string)
by 张沈鹏 01 Oct '06

01 Oct '06

It's seems faster than the algorithm now in use. The execute file and project file please see the attach. DateValidate cost : 00:00:17.765546 boost_date_validate cost : 00:00:50.232232 Below is cpp source of the algorithm and test ---------------------------------------------------------------------------------------- #include <boost/lexical_cast.hpp> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <iostream> #include <string> #include <boost/date_time/posix_time/posix_time.hpp> using namespace std; using namespace boost; using namespace boost::posix_time; using namespace boost::gregorian; int create_date() { int year=rand() %200+1900; int month=rand() %20; int day=rand() %40; return year*10000+month*100+day; } void date_validate(int date) { static int daysOfMonth[] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 }; int monthDay = date % 10000; if (monthDay >= 1300) throw bad_month(); if (monthDay > 1231) throw bad_day_of_month(); if (monthDay == 229) { int year = date / 10000; if ( (year % 4) != 0) throw bad_day_of_month(); if (year %100 == 0 && year % 16 != 0) throw bad_day_of_month(); } int month = monthDay / 100; int day = monthDay % 100; if (! (day > 0 && day <= daysOfMonth[month]) ) throw bad_day_of_month(); } bool DateValidate (string date) { try { date_validate( lexical_cast<int> (date)); return true; } catch (...) { return false; } } bool boost_date_validate (string date) { try { from_undelimited_string (date); return true; } catch (...) { return false; } } int main() { int n=1000000; ptime createDateBegin (microsec_clock::local_time() ); for (int i=0;i<n;i++) { int r=create_date(); string t=lexical_cast<string> (r); } ptime createDateEnd (microsec_clock::local_time() ); time_duration createTime=createDateEnd-createDateBegin; cout<<"create_date cost : "<<createDateEnd-createDateBegin<<"\n"; createDateBegin=microsec_clock::local_time(); for (int i=0;i<n;i++) { int r=create_date(); string t=lexical_cast<string> (r); DateValidate (t); } createDateEnd=microsec_clock::local_time(); cout<<"DateValidate cost : "<<createDateEnd-createDateBegin-createTime<<"\n"; createDateBegin=microsec_clock::local_time(); for (int i=0;i<n;i++) { int r=create_date(); string t=lexical_cast<string> (r); boost_date_validate (t); } createDateEnd=microsec_clock::local_time(); cout<<"boost_date_validate cost : "<<createDateEnd-createDateBegin-createTime<<"\n"; cin.get(); return 0; }

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[date_time] Warnings in VC8
by Arkadiy Vertleyb 01 Oct '06

01 Oct '06

Hi, I am getting a few "possible loss of data" warnings while using the datetime library. For example, VC8 complains about the following code in microsec_clock.hpp: boost::uint64_t filetime = ... ... boost::uint32_t sub_sec = (filetime % 10000000) / 10; // microseconds The compiler also complains about similar issue in from_ftime. Is this a known issue? Regards, Arkadiy

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[date_time/posix_time] [Fwd: Warnings with microsec_time_clock.hpp with VC8.0]
by Bill Somerville 01 Oct '06

01 Oct '06

-- Bill Somerville This message has been scanned by MailController - www.MailController.altohiway.com

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date_time: convert std::time_t to printable date in local time
by Andreas Ntaflos 01 Oct '06

01 Oct '06

Hello boost-users, I am quite new to Boost and this is my first post to this list. My problem is quite similar to one posted to this list two years ago [1]. Since there don't seem to be any follow-ups to that message I hope to find an answer by posting here. A program of mine reads a Unix timestamp from a database (the field is simply of type NUMERIC(10,0), written to by PHP's time() [2] function) into a `std::time_t time' object, holding the seconds since the epoch, in UTC. No time zone adjustments are applied as far as I understood. I need to convert this time_t to a ptime (or any other kind of printable, readable string) with time zone adjustments applied. Converting with the from_time_t() method works fine, except that the resulting date and time are still in UTC. What would be the most simple way to have the time_t converted to a ptime with local time zone adjustments? The time zone could be any but it would suffice if it is the one the computer running the program is in. I could even hardcode the time zone into the program. Hopefully I made enough sense to have someone knowing help me out. RTFM answers are most welcome, although I have read much of the docs on the date_time library on the Boost homepage. So if possible please point me to the section in the that is relevant to my problem. If this is not possible with Boost are there any other functions I could use, probably from the standard library? Thanks a lot in advance! Andreas [1] Very long Google cache link: http://www.google.com/search?q=cache:s-MYu63Ev8UJ:lists.boost.org/MailArchi… [2] http://www.php.net/manual/en/function.time.php -- Andreas "daff" Ntaflos Vienna, Austria GPG Fingerprint: 6234 2E8E 5C81 C6CB E5EC 7E65 397C E2A8 090C A9B4

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lambda boost::array operator[] error
by Levent Yilmaz 30 Sep '06

30 Sep '06

Hi All, Please take a look these two similar set of statements. One uses vector, the other boost::array : /**/ using std::vector; using boost::array; using std::for_each; using boost::lambda::_1; // This one compiles: typedef vector<int> Vector; Vector v(2); vector<Vector> vv(5,v); for_each( vv.begin(), vv.end(), (_1[0]=10, _1[1]=9) ); // This one doesn't: typedef array<int,2> Array; vector<Array> va(5); for_each( va.begin(), va.end(), (_1[0]=10, _1[1]=9) ); /**/ With MSVC 7.1, I get: ===== d:\boost\include\boost-1_33_1\boost\lambda\detail\operator_lambda_func_base.hpp(237): error C2679: binary '=' : no operator found which takes a right-hand operand of type 'const boost::tuples::cons<HT,TT>::stored_head_type' (or there is no acceptable conversion) with [ HT=const boost::lambda::detail::parameter_traits_<const int,const boost::lambda::detail::IF<false,const int &,const int>::RET>::type, TT=boost::tuples::detail::map_tuple_to_cons<boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>::type ] ====================================================== With gcc 3.4.4, I get a moderately sized novel, whose last line reads: ===== /usr/local/include/boost/lambda/detail/operator_lambda_func_base.hpp:136: error: conversion from `int' to non-scalar type `boost::lambda::detail::unspecified' requested ======================================================= This is boost version 1.33.1. What could be wrong? thx

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BoostCon 2007 Call for Proposals
by Beman Dawes 30 Sep '06

30 Sep '06

The first annual Boost conference will take place in Aspen, Colorado, May 14-18, 2007. BoostCon 2007 is looking for session presenters. We invite you to propose a session. For details on how to become a presenter, see www.boost.org/more/BoostCon07_session_call.html This inaugural Boost conference promises to be the main face-to-face venue for all things Boost, from using libraries to writing them, from evangelizing Boost to deployment within your organization, from infrastructure and process to vision and mission, and from TR1 to TR2. Given the range and interests of the participants, the event is going to be intense and in-depth. For more information about the conference, see www.boost.org/more/BoostCon07.html --The Organizing Committee David Abrahams Beman Dawes Jeff Garland Joel de Guzman Kevlin Henney Howard Hinnant Scott Meyers Eric Niebler Sean Parent Rene Rivera Jeremy Siek Matthias Troyer

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Fwd: boost regex library problem with release build
by Maggie Nguyen 30 Sep '06

30 Sep '06

I fixed the problem. For debug: my project setting as: C/C++ > Code Generation > Runtime LIbrary as "Multi-threaded DLL (/MD)" But in my release setting: C/C++ > Code Generation > Runtime LIbrary as "Multi-threaded (/MT)" When I changed it to "Multi-threaded DLL (/MD)", then it works! As indicated in the boost/boost/config/user.hpp, which needs _DLL flag. Thanks, Maggie ---------- Forwarded message ---------- From: maggie.nguyen(a)gmail.com <maggie.nguyen(a)gmail.com> Date: Sep 29, 2006 9:45 AM Subject: boost regex library problem with release build To: Hi, I use Visual Studios 2005. In my project file, I include the library in linker: "Additional Library Directories: ..\..\boost\lib" I have these libs in the boost\lib directory: libboost_date_time-vc80-mt-1_33_1.lib libboost_date_time-vc80-mt-gd-1_33_1.lib libboost_regex-vc80-mt-1_33_1.lib libboost_regex-vc80-mt-gd-1_33_1.lib libboost_thread-vc80-mt-1_33_1.lib libboost_thread-vc80-mt-gd-1_33_1.lib When I build my project as a debug build. it compiles fine. However, if I change to release build, it gives me this error: Error 1 fatal error LNK1104: cannot open file 'libboost_regex-vc80-mt-s-1_33_1.lib' Please let me know what I need to do to have it point to "libboost_regex-vc80-mt-1_33_1.lib" instead of "libboost_regex-vc80-mt-s-1_33_1.lib". Thanks very much, Maggie

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boost regex library problem with release build
by Maggie Nguyen 29 Sep '06

29 Sep '06

Hi, I use Visual Studios 2005. In my project file, I include the library in linker: "Additional Library Directories: ..\..\boost\lib" I have these libs in the boost\lib directory: libboost_date_time-vc80-mt-1_33_1.lib libboost_date_time-vc80-mt-gd-1_33_1.lib libboost_regex-vc80-mt-1_33_1.lib libboost_regex-vc80-mt-gd-1_33_1.lib libboost_thread-vc80-mt-1_33_1.lib libboost_thread-vc80-mt-gd-1_33_1.lib When I build my project as a debug build. it compiles fine. However, if I change to release build, it gives me this error: Error 1 fatal error LNK1104: cannot open file 'libboost_regex-vc80-mt-s-1_33_1.lib' Please let me know what I need to do to have it point to "libboost_regex-vc80-mt-1_33_1.lib" instead of "libboost_regex-vc80-mt-s-1_33_1.lib". Thanks very much, Maggie

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