July 2006 - Boost - lists.preview.boost.org

interest in sorted vector containers?
by Lewis Hyatt 02 Aug '06

02 Aug '06

Hi Everyone- Is there any interest in providing Boost container classes with the same functionality as set/map implemented with sorted vectors? I have four simple classes vset, vmap, vmultiset, vmap which do this. It seems like it would be quite useful, especially since, in my experience, set and map are heavily overused because of their convenience even when the insertion efficiency and iterator invalidation guarantees are not necessary. My classes provide the same interface as the STL equivalent, with additional functions such as nth_element() that take advantage of the random access iterators, and some conveniences like key-only and value-only iterators for vmap and vmultimap. I can post the code with a first attempt at making it appropriate for Boost if people think it is worth it? -Lewis

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Is there any interest in a UTF-8 library?
by Nemanja Trifunovic 02 Aug '06

02 Aug '06

Hello everybody. I have just released Beta 2 version of a small (one header file) generic library for handling UTF-8 encoded strings - you can read more about it at http://utfcpp.sourceforge.net/ . Is there any interest in adding this library too Boost? Either as a separate library or maybe as an addition to some of existing ones. Thanks. Nemanja Trifunovic --------------------------------- See the all-new, redesigned Yahoo.com. Check it out.

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[serialization] facets for non-finite numbers
by Johan Råde 02 Aug '06

02 Aug '06

At the suggestion of Robert Ramey's, I have put together facets for reading and writing non-finite numbers, such as infinity and not-a-number, to text streams, in a consistent and portable way. The code, with documentation and tests, is available in the Boost Vault, serialization/non_finite_num_facets.zip. If there is enough interest in the code, I will submit it for a mini-review, in order to have it added to the serialization lib. --------------------------------------------- What does the code do? The following test fails on VC++ 7.1: stringstream s; double x = numeric_limits<double>::infinity(); double y; ss << x; ss >> y; assert(x == y); The situation gets even worse when text files are required to be portable between different platforms. But the following test succeeds: stringstream s; locale old_locale; locale tmp_locale(old_locale, new extended_num_put<char>); locale new_locale(tmp_locale, new extended_num_get<char>); s.imbue(new_locale); double x = numeric_limits<double>::infinity(); double y; ss << x; ss >> y; assert(x == y); For more info, read the documentation. ------------------------------------------------------------ --Johan Råde

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is_nan
by Joe Gottman 02 Aug '06

02 Aug '06

Several libraries have an is_nan() function buried deep in the code. Are there any plans to make a general is_nan function available? This would be quite useful, as well as similar functions like is_finite. Joe Gottman

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numeric::interval::abs() bug
by Terry Golubiewski 02 Aug '06

02 Aug '06

The following code does not compile with g++ nor MSVC 2003 because of ambiguity of first argument to std::max() in numeric::abs(). Is a typecast needed in interval/utility.hpp? terry #include <boost/numeric/interval.hpp> #include <iostream> typedef boost::numeric::interval<short> Interval; std::ostream& operator<<(std::ostream& os, const Interval& x) { return os << x.lower() << ".." << x.upper(); } int main() { Interval r1(-3, 7); std::cout << "r1=" << r1 << std::endl; Interval r2 = boost::numeric::abs(r1); std::cout << "r2=" << r2 << std::endl; return 0; } // main

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bind/lambda/phoenix and result_of
by David Abrahams 02 Aug '06

02 Aug '06

One happy day, we'll have auto and decltype... Until then, we have no reasonable way to declare the type of bind expressions. So I got to thinking, maybe something like this could be made to work: result_of<bind_(std::minus<int>, int, _1_)>::type f = bind(std::minus<int>(), 3, _1); For lambda, I guess we could do something like this: result_of<minus_(int, _1_)>::type f = 3 - _1; Does this direction make sense? -- Dave Abrahams Boost Consulting www.boost-consulting.com

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Getting a xsd:datetime from boost::date_time
by Joe Van Dyk 02 Aug '06

02 Aug '06

Hi, (sorry if this is off topic) I need to get the current date and time and convert it into a string that follows the xsd:datetime time stamp format: [-]CCYY-MM-DDThh:mm:ss[Z|(+|-)hh:mm]. (timezone should be UTC) Any ideas on how to do that? The Boost::Date_Time library documentation is confusing to my feeble mind. Thanks, Joe

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library for type erasure
by Steven Watanabe 01 Aug '06

01 Aug '06

AMDG Is there any interest in a library for type erasure? My basic idea is to define each operation separately and use a sequence of them. As a simple example: void f() { erasure<boost::mpl::vector<ostreamable, incrementable> > object(0); ++object; std::cout << object; //prints 1 } In Christ, Steven Watanabe

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[boostbook] Extra space after void parameter declaration
by Julio M. Merino Vidal 01 Aug '06

01 Aug '06

Hi, I usually write function declarations that do not take any parameters using the "old" C style; that is: int foo(void); I've now started documenting my code using Doxygen and integrating the resulting documentation into a Quickbook document. The class summary is correctly formatted because it does not include the parameter names, but the function prototypes in their description show: int foo(void ); Note the extra space after void. It looks ugly and I believe it should not be there. The attached patch seems to fix this issue. Can it be integrated? Thanks, -- Julio M. Merino Vidal <jmmv84(a)gmail.com> The Julipedia - http://julipedia.blogspot.com/

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Boost regression testing status
by Gennaro Prota 01 Aug '06

01 Aug '06

Hi, I'd like to point your attention toward the current status of our regression testing. I'll not express opinions, but these are some facts about 1.34: - Huang-WinXP-x64 - graph - graphviz_test / msvc-8.0 LINK : fatal error LNK1181: cannot open input file '[...]\bgl-viz-vc80-gd-1_34.lib' - For some failures no error message is reported, so that it is pretty much impossible for the developer to fix them; e.g.: http://tinyurl.com/zmpwk - metacomm-v2 - algorithm/minmax - minmax / msvc-7.0 'vsvars32.bat' is not recognized as an internal or external command... - OSL4-V2 - python - andreas_beyer / sun-5.8 #error Python 2.2 or higher is required for this version of Boost.Python. - RudbekAssociates-V2 - iostreams - bzip2_test / msvc-7.1 LINK : fatal error LNK1181: cannot open input file '[...]\boost_iostreams-vc71-gd-1_34.lib' The list is not exhaustive. -- [ Gennaro Prota, C++ developer for hire ]

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