April 2010 - Boost-users - lists.preview.boost.org

Compiling on HPUX RISC
by Marc Bernier 08 Apr '10

08 Apr '10

We are compiling the boost library (just the RegEx portion) on an HP-UX machine using the aCC compiler v A.03.70. Straight off, it does not compile (a #error in hp_acc.hpp reports that version A.03.80 or higher is needed). We can suppress the error, but we quickly run into a compiler error "Not enough memory is available to finish the compilation". My suspicion is that the aCC compiler restriction was imposed because of this very problem and that there is no work-around. But I'd like to confirm this, and if I'm wrong, are there any suggestions or work-arounds that anyone may have. Unfortunately, we cannot upgrade our compiler due to customer requirements. --Marc Bernier

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logical operators in lambda
by Conoscenza Silente 08 Apr '10

08 Apr '10

Hi All I am trying to use boost::lambda using logicat operator. I would like to use it in a STL std::find_if call. What I receive is always the same error error: no match for ‘operator==’ in ‘boost::lambda::<unnamed>::_1 == 13’ Do you know what I am doing wrong? Thanks AFG using namespace boost::assign; int main( int argc, char** argv ){ std::vector< int > v; v += 12,13,14,15; bool found_tmp = false; boost::lambda::var_type< bool >::type found( boost::lambda::var(found_tmp) ); std::find_if( v.begin(), v.end(), ( found = ( boost::lambda::_1 == 13 ), return found ) ); }

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boost::filesystem::rename
by immanuel litzroth 08 Apr '10

08 Apr '10

Morning List, looking at the documentation of >template <class Path1, class Path2> void rename(const Path1& from_p, const Path2& to_p); > > Requires: Path1::external_string_type and Path2::external_string_type are the same type. > > Effects: Renames from_p to to_p, as if by POSIX rename(). > > Postconditions: !exists(from_p) && exists(to_p), and the contents and attributes of the file originally named from_p are otherwise unchanged. > > [Note: If from_p and to_p resolve to the same file, no action is taken. Otherwise, if to_p resolves to an existing file, it is removed. A symbolic link >is itself renamed, rather than the file it > resolves to being renamed. -- end note] that does not seem to be what the code does since it checks whether to_p exists and throws an error if it does. I need an atomic overwrite to an existing file since that filename is generated by mkstemp. What will be the semantics of rename i.e. is the documentation in error or is the code (or am I missing something)? Thanks in advance, Immanuel

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Re: [Boost-users] std::list and intrusive_list
by Hicham Mouline 08 Apr '10

08 Apr '10

-----Original Message-----From: strasser(a)uni-bremen.deDate: 07/04/2010 10:28 PMTo: boost-users(a)lists.boost.orgSubject: Re: [Boost-users] std::list and intrusive_listZitat von Hicham Mouline <hicham(a)mouline.org>;: > Hello, I have say 10 (could very well be 1000) instances of const > std::list containers holding the same type T.T is a boost::tuple, > the first field of which is boost::gregorian::date, 4 other double > fields.All the lists are ordered by date. The first, last dates > ranges overlap across lists.The size of each list is of the order of > a 10000 entries. The lists may have different sizes.Further > development of the product may lead to millions of entries in each > list.The objective is to get a uniform set of 10 ranges of dates > from these 10 lists.That is, 1. we apply first an external > [start,finish] date range and reduce the viable entries in each list > to those included in this range.2. As start and finish might not > match a date present in some/all the lists, we further reduce this > date range until we find a range [actual_start, actual_finish] with > these bounds present in all the 10 lists.3. At this stage, we want > to take the union of all the dates available in all the 10 lists, > and where the dates are missing, set the entries to values from the > previous entry in the same list.As the lists are const, and may be > very large, I wish not to modify nor copy the lists to add the > missing dates in each of the 10 list.Instead I thought of adding a > second std::list for each of the 10 lists, and somehow treat the > combined 2 lists as 1 input, using a begin/end pair of iterators > that would iterate over the combined 2 lists as if they were 1 > list.This is impossible to do if I also want to have these iterators > _be_ std::list<T>::iterator.However, if I relax this constraint, I > should be able to write a new iterator class (bidirectional like > list's) that take the 2 lists and would let me iterate over the > combination.Can Boost.Intrusive's list help with this?regards,that was slightly confusing, but IIUC you need an iterator that merges multiple sorted ranges. you could write a boost::iterator_facade that uses a std::priority_queue to decide which of the underlying lists contains the next value. if you can store the resulting list, you can use std::merge/std::inplace_merge instead. _______________________________________________ All right, I will use a boost::iterator_facade. Thank you,

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[Boost.Test] Floating point NAN comparison
by Brian O'Kennedy 08 Apr '10

08 Apr '10

Hi, This bit of Boost.Test code fails: ////////////////////////////////////////////////////////////////////// BOOST_AUTO_TEST_CASE( nantest ) { float a,b; a = b = 1.0; BOOST_CHECK_EQUAL( a, b ); // passes a = b = NAN; BOOST_CHECK_EQUAL( a, b ); // fails } ////////////////////////////////////////////////////////////////////// The failure is because, by definition, NAN != NAN. What I'm after is a test macro which takes this into account and will pass the equality test when both elements are NAN. BOOST_CHECK_CLOSE has the same behaviour. Is the best solution to write my own custom predicate? Brian

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library linking
by mh00219＠surrey.ac.uk 08 Apr '10

08 Apr '10

hello, I am a new student to C++ and using boost libraries in my project. I have a problem please solve it. I am using boost header files in my programs. When I compile using g++ on cygwin by giving the path of boost root directory (c:\boost\boost_1_42_0) it is ok. But when I try to make .exe file from .o file then it gives me error. Please tell me how should I link boost libraries to my program? in which directory are these boost libraries.? please reply must. my whole project is just a pice of writing nothing else. thank you

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How to use property_map?
by Yaohua Xiong 08 Apr '10

08 Apr '10

Hi, I'm trying to figure out how to use property_map in boost graph, after I reduce the problem to the minimal I still don't know what the problem is. Can someone help with this? Thanks in advance. Here is the simplified example: #include <iostream> #include <map> #include <string> #include <boost/property_map/property_map.hpp> using std::string; using boost::put; using boost::get; int main() { typedef std::map<std::string, int> Map; typedef boost::associative_property_map<Map> PMap; PMap map; put(map, string("acc"), 1); get(map, string("acc")); return EXIT_SUCCESS; } This version compiles OK with mingw 4.4, but crash when running. If I make a change from "PMap map;" into "PMap map();" which I think is equivalent, then this code fail to compile, and say D:\myproject\test\boost_test\property_map\pp.cpp: In function 'int main()': D:\myproject\test\boost_test\property_map\pp.cpp:15: error: no matching function for call to 'put(main()::PMap (&)(), std::string, int)' D:\myproject\test\boost_test\property_map\pp.cpp:16: error: no matching function for call to 'get(main()::PMap (&)(), std::string)' What's the problem is? -- Yaohua Xiong Traffic and Transportation Engineering College, Tongji Univ. Cao An Road 4800#, Jia Ding District, Shanghai, China

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[Boost.UTF] Documentation issues
by Adam Nielsen 07 Apr '10

07 Apr '10

Hi all, Just reporting a couple of issues I've come across with the Boost test framework documentation. Would it be possible to get an explanation of the --break_exec_path option added to the runtime parameter reference? http://www.boost.org/doc/libs/1_42_0/libs/test/doc/html/utf/user-guide/runt… On the main doc page http://www.boost.org/doc/libs/1_42_0/libs/test/doc/html/utf.html the link to BOOST_TEST_PASSPOINT goes to the wrong page. Cheers, Adam.

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[Boost.UTF] Suggestion - test tracking
by Adam Nielsen 07 Apr '10

07 Apr '10

Hi all, I have a suggestion for the Boost unit-test library. If this is already possible and I've just missed it, please let me know. It would be nice if there was a sure-fire way to guarantee certain parts of the code were being tested. For example an if/else statement would ideally have tests that cover both execution paths, but at the moment this relies on coding the tests correctly. It's possible to make a mistake in the test and cause it to succeed without actually testing the code in question, and because the test succeeds you may never notice. Would it be possible to have something like a BOOST_TESTED_BY macro, which causes the named test to fail if it completes without running that line? (As well as documenting where that part of the code is tested.) For example: if (condition) { BOOST_TESTED_BY(my_test); } else { BOOST_TESTED_BY(my_other_test); } BOOST_AUTO_TEST_CASE(my_test) { // This test fails if BOOST_TESTED_BY(my_test) doesn't run } Of course this is a simplified example, you'd probably want counts and things as well, but I thought it might be a useful addition to the test framework (assuming it can't be done already!) Thanks, Adam.

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std::list and intrusive_list
by Hicham Mouline 07 Apr '10

07 Apr '10

Hello, I have say 10 (could very well be 1000) instances of const std::list containers holding the same type T.T is a boost::tuple, the first field of which is boost::gregorian::date, 4 other double fields.All the lists are ordered by date. The first, last dates ranges overlap across lists.The size of each list is of the order of a 10000 entries. The lists may have different sizes.Further development of the product may lead to millions of entries in each list.The objective is to get a uniform set of 10 ranges of dates from these 10 lists.That is, 1. we apply first an external [start,finish] date range and reduce the viable entries in each list to those included in this range.2. As start and finish might not match a date present in some/all the lists, we further reduce this date range until we find a range [actual_start, actual_finish] with these bounds present in all the 10 lists.3. At this stage, we want to take the union of all the dates available in all the 10 lists, and where the dates are missing, set the entries to values from the previous entry in the same list.As the lists are const, and may be very large, I wish not to modify nor copy the lists to add the missing dates in each of the 10 list.Instead I thought of adding a second std::list for each of the 10 lists, and somehow treat the combined 2 lists as 1 input, using a begin/end pair of iterators that would iterate over the combined 2 lists as if they were 1 list.This is impossible to do if I also want to have these iterators _be_ std::list<T>::iterator.However, if I relax this constraint, I should be able to write a new iterator class (bidirectional like list's) that take the 2 lists and would let me iterate over the combination.Can Boost.Intrusive's list help with this?regards,

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