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[program_options][filesystem] custom validator for std::vector<filesystem::path>
by Chris Weed 19 Jan '06

19 Jan '06

Hi, I made a custom validator for filesystem::path and that works, but I can't seem to get the same to work for std::vector<filesystem::path>. I keep getting an exception about multiple_occurrences when I use it. Here is the code for the validator: void validate(boost::any& v, const std::vector<std::string>& values, std::vector<boost::filesystem::path>* target_type, int) { using namespace boost::program_options; // Make sure no previous assignment to 'v' was made. validators::check_first_occurrence(v); std::vector<boost::filesystem::path> result; for(size_t i=0;i<values.size();++i) { result.push_back(boost::filesystem::path(values[i])); } v = boost::any(result); } Thanks, Chris

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[Boost-bugs] [ boost-Bugs-1409932 ] boost::archive tmpdir.hpp multiply defined symbol
by SourceForge.net 19 Jan '06

19 Jan '06

Bugs item #1409932, was opened at 2006-01-19 09:35 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1409932&group_… Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: serialization Group: None Status: Open Resolution: None Priority: 5 Submitted By: Billy B (baxissimo) Assigned to: Robert Ramey (ramey) Summary: boost::archive tmpdir.hpp multiply defined symbol Initial Comment: Revision 1.6 of boost/boost/boost/archive/tmpdir.hpp just contains a plain function right there in the header. If it gets #included into multiple translation units then it creates multiply defined symbols. The simple solution is to declare it as 'inline'. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1409932&group_… ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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[constrained_types] Use cases survey
by Robert Kawulak 19 Jan '06

19 Jan '06

Hi, Some time ago there was a discussion on the Constrained Types library. Unfortunately other duties didn't let me work on it for a long time (I apologise for this long break), but recently I started the work again. As a reminder, or short description for those who missed the discussion, there's a brief summary of usage of the library at the end of this message. I need help in determining the most common use cases of the library. Therefore I ask anybody who ever needed such a facility to write what exactly he needed it for, what were his expectations and requirements for functionality and efficiency. In particular, answers for the following questions would be useful (but all opinions and suggestions are valuable): - Is it worth to make different implementation of increment/decrement functions for integer types to make them much more efficient than the generic versions? This needs complicating the design a little bit (but not the usage). OTOH only ++/-- would be optimised, other operators not. So is ++/-- operation actually more common than the others that it's worth it? - Is such a feature likely to be needed: a possibility to select different out-of-bounds policies for both the bounds, e.g. throw when the lower bound is exceeded, clip when upper bound is exceeded. - How often would people need this library to work with types other than integral or floating-point? What kind of types would it be (cheap/expensive to copy)? Any answers, suggestions, advice and questions are welcome. Best regards, Robert EXAMPLES: struct is_even { bool operator()(int v) const { return (v % 2) == 0; } }; constrained<int, is_even>::type even_int(0); even_int += 4; // OK even_int = 1; // error - throws BOOST_DEFINE_VALUE_GENERATOR(abc_type, std::string, "abc"); BOOST_DEFINE_VALUE_GENERATOR(xyz_type, std::string, "xyz"); bounded<std::string, abc_type, xyz_type>::type my_string; // my_string == "abc" s = "x"; // OK s += "zz"; // throws - "xzz" is not within the range bounded_int<int, 0, 5, error::do_nothing>::type my_int; // my_int == 0 my_int++; // OK my_int *= 100; // invalid operation ignored, still my_int == 1 wrapping_int<unsigned_int, 5, 10>::type wraps; // wraps == 5 wraps--; // wraps == 10 wraps += 2; // wraps == 6 saturating<std::string, abc_type, xyz_type>::type clips; // clips == "abc" clips = "z"; // clips == "xyz" - value clipped to the upper bound These are just the simpliest examples. Other features are: - policy-based design allowing customizations like different constraint, error or out-of-bounds policy classes, - any of the bounds may be excluded from the allowed set of values (open ranges), - bounds may be adjustable at run-time or defined at compile-time, - and some more I can't remember at the moment ;-) ------------------------------------------------------------------- Zmyslowa czerwien... >>> http://link.interia.pl/f18f0

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Using CVS to get Boost work-in-progress
by Paul A Bristow 19 Jan '06

19 Jan '06

I have wanted to try out the latest Boost test, post 1.33.1 release, but I remembered what a hassle I found using CVS command line interface, and it was not obvious to me how to use the browser interface, fine for a single files, to get all the files for test, for example, headers, others sources, examples and docs, so I decided to try using a GUI version instead. After downloading WinCVS (and CVSNT) I started it up, but quickly decided something else was much more urgent ;-) It would be very helpful if someone could produce a "CVS/Boost for Dummies" guide to configuring/using so that one can get the latest (and hopefully greatest) for a **single project** without too much brain hurt. (I don't want the full Boost update - I think?). Suggestions most welcome. Paul -- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB Phone and SMS text +44 1539 561830, Mobile and SMS text +44 7714 330204 mailto: pbristow(a)hetp.u-net.com http://www.hetp.u-net.com/index.html http://www.hetp.u-net.com/Paul%20A%20Bristow%20info.html

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[Boost-bugs] [ boost-Support Requests-1409774 ] Building universal binary on MacOSX
by SourceForge.net 19 Jan '06

19 Jan '06

Support Requests item #1409774, was opened at 2006-01-19 12:00 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=207586&aid=1409774&group_… Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Building Boost Group: None Status: Open Resolution: None Priority: 5 Submitted By: Shai Shasag (shaishasag) Assigned to: Nobody/Anonymous (nobody) Summary: Building universal binary on MacOSX Initial Comment: I'm using boost libraries on Windows (VC++) And MacOSX (gcc). Currently on MacOSX boost compiles for PPC processor. As Apple is moving to Intel processors, I would like to be able to compile boost, on the Mac for both PPC and Intel. Apple created the universal binary format, where you compile and link the code twice, the only difference in the compilation is a single option: -arch ppc or -arch i386. Later a tool called CreateUniversalBinary is called upon the linked codes. CreateUniversalBinary merges the two binaries into one. During runtime, the operating system loads the code and chooses which part to run, according to the local processor. I tried looking into the jamfiles but was overwhelmed by the complexity. What would be the best method to achieve universal binary on MacOSX? ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=207586&aid=1409774&group_… ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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BOSOT_ENUM proposal rev 4
by Frank Laub 19 Jan '06

19 Jan '06

I've updated the BOOST_ENUM stuff in the file vault: *http://tinyurl.com/cznqu * Currently, there are three flavors of enumerated types available. 1. BOOST_ENUM This type of enum provides the user with a simple way to express an enum. example usage: BOOST_ENUM(boolean, (False) (True) ) This flavor does not allow each element of the enum to be defined. It is assumed that the first element will begin with the value 0 and the last element will be equal to the count of elements - 1. The following methods are available with this type: static const_iterator begin() static const_iterator end() static boost::optional<const T> get(size_t index) static boost::optional<const T> parse(const char* str) const char* str() const bool operator == (const T& rhs) const bool operator != (const T& rhs) const ostream& operator << (ostream& os, const T& rhs) 2. BOOST_ENUM_VALUES This flavor of enum is the same as the basic enum flavor but it allows the user to specify values for each element. example usage: BOOST_ENUM_VALUES(VirtualKey, (Space)(0x20) (Prior)(0x21) (Next)(0x22) (End)(0x23) (Home)(0x24) ) In addition to the methods described above with the basic flavor, these are also available: static boost::optional<const T> make(size_t value) size_t value() const 3. BOOST_BITFIELD A bitfield is much like a BOOST_ENUM_VALUES except that each value is interpreted as a bitmask. This allows many common bitmask operations to be done in a more elegant way; forcing the user to only use bitmasks that are in the domain of the defined bitfield. example usage: BOOST_BITFIELD(MouseKey, (LeftButton)(0x0001) (RightButton)(0x0002) (Shift)(0x0004) (Control)(0x0008) (MiddleButton)(0x0010) ) This type has all of the methods defined for a BOOST_ENUM_VALUES along with these: static T all_mask() std::string str() const void operator |= (const T& rhs) T operator | (const T& rhs) const size_t operator & (const T& rhs) const // TODO: add some more of these like &=, ~, etc. str() for this type returns a string instead of a const char* because it has to generate the string on the fly for each instance. Perhaps there is a more compile-time approach, but I think this would involve lots of tagged type lists and such. Taking the MouseKey as an example, one can do this: MouseKey mkLeft = MouseKey::LeftButton; MouseKey mkShift = MouseKey::Shift; MouseKey mk = mkLeft | mkShift; cout << mk << endl; The output will be: LeftButton | Shift Implementation notes: Instead of needing an 'Invalid' element, I just use Boost.Optional now. Thanks a ton for that suggestion Yuval! Using a switch/case instead of an array for storage of the strings and values of the enum turned out to be pretty straight-forward. With this approach, as was noted earlier, there should be no thread safety issues. I've looked at the disassembly of an optimized example with VC8 and it looks like the compiler just gets rid of all the overhead anyway. I also found that using a switch/case made it possible to be re-used across the many flavors. These types are now instanciable, and I think it is much easier/cleaner to use. Instances of BOOST_ENUM and BOOST_ENUM_VALUES store not the value of the enum element, but the index that it appears in the defining sequence. BOOST_ENUM is actually special because its index always matches its value. Because of this, BOOST_ENUM_VALUES takes a small hit for the make() method because it needs to walk through all of the available values and find one that matches. The tricky thing for the user is that make() will return the first element that matches. So if a user defines A and B to both be equal to 10, and the user calls make(10), it will return A. However if the user defines B before A, make(10) will return B. BOOST_BITFIELD stores the actual raw value so that all of the bitwise operators will be fast and efficient. In a previous attempt to write this flavor, I used a std::set<size_t> of indicies. This is expensive both for the bitwise operators and the storage requirements for each instance of this type. The consequence of storing the raw value is that the str() method has a bit of overhead since it has to mask off each element and check to see if the remaining bits match any values defined in the sequence. It also means that, like BOOST_ENUM_VALUES, the order in which the user defines each bitfield element can change the resulting string representation. As always, any comments are much appreciated. -Frank

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[string_algo] iless?
by Sebastian Redl 19 Jan '06

19 Jan '06

Hi, It's easy to sort a container of std::strings lexicographically. Just sort it - string's < operator takes care of things. But what if I wanted to do a case-insensitive sort? There's no predicate for case-insensitive comparison in the standard library, so I turned to the next logical place: Boost's string algorithm library. But while there's iequals, I couldn't find iless. It seems to me like this predicate would be quite useful. Yes, I know how complicated full-blown Unicode CI sorting can be. I read Sorting It All Out. But I think most people are looking for something simpler anyway. Sebastian Redl

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[database] sql statements
by Andy Tompkins 18 Jan '06

18 Jan '06

I think that most people either define their statement directly in code (ie. string sql("SELECT * FROM ORDERS");), or put the same string in a resource and load it. The application that I work on often builds complex statements from user input and requires a lot of code to create the correct sql statement. I would like something that delimits table and column names: "table 1" "column 1" => "[table 1].[column 1]"), inserts commas in lists (ie SELECT "c1" "c2" "c3" => "SELECT [c1], [c2], [c3]), and manages table aliases (ie SELECT table1.column FROM table1 AS t1 => "SELECT [t1].[column] FROM [table1] AS [t1]"). It would also be nice if it know what dialect of sql it is working with and thus abstract away from that so one can have one piece of code know how to make the sql statement correct for Microsoft jet, mysql, ANSI SQL92, etc. eg: stringstream << select << column("c1") << column("table1", "column2") << from << table("table1").as("t1"); => "SELECT [c1], [t1].[column2] FROM [table1] AS [t1]" I believe that a database library for boost should include something like this.

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[database]
by Andy Tompkins 18 Jan '06

18 Jan '06

I think that most people either define their sql statement directly in code (ie. string sql("SELECT * FROM ORDERS");), or put the same string in a resource and load it. The application that I work on often builds complex statements from user input and requires a lot of code to create the correct sql statement. I would like something that delimits table and column names: "table 1" "column 1" => "[table 1].[column 1]" inserts commas in lists: SELECT "c1" "c2" "c3" => "SELECT [c1], [c2], [c3] and manages table aliases: SELECT table1.column FROM table1 AS t1 => "SELECT [t1].[column] FROM [table1] AS [t1]" It would also be nice if it knew what dialect of sql it is working with and thus abstract away from that. Then one piece of code would know how to make the sql statement correct for Microsoft jet, mysql, ANSI SQL92, etc. eg: stringstream s << select << column("c1") << column("table1", "column2") << from << table("table1").as("t1"); assert(s.str() == "SELECT [c1], [t1].[column2] FROM [table1] AS [t1]"); Is their a library that helps the user form sql statements in code? I believe that a database library for boost should include something like this. Andy

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Re: [boost] Can't understand how the BOOST_PP_REPEAT_FROM_TO exampleworks]
by Bradley Smith 18 Jan '06

18 Jan '06

Thanks Paul, So are you saying that the preprocessor should look at BOOST_PP_REPEAT_FROM_TO and begin expanding that first, in isolation from what follows next on the line i.e. the parameters that are to be passed to whatever BOOST_PP_REPEAT_FROM_TO "returns", and then reset the macro replacement stack before continuing? That would explain a lot. It would also explain why even if I modify the other code to this: #define CONCAT_1(a, b) CONCAT_1_D(a, b) #define CONCAT_1_D(a, b) a ## b #define CONCAT_2(a, b) CONCAT_2_D(a, b) #define CONCAT_2_D(a, b) a ## b #define AB(c, x, y) CONCAT_ ## c(x,y) #define CONCAT CONCAT_1 CONCAT(A, B(1, p, q)) // Not calling CONCAT_1 directly any more Expansion still stops early because after expanding CONCAT (which is not a function macro this time) and deleting the replacement stack we are still kicking the next lot of expansion off with CONCAT_1, so we cannot expand it again? Thanks for your time Paul. I tried responding personally but your mail server considers me to be a spammer ;-) Brad

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