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[bigint] Integer data type larger than 64 bits?
by Simonson, Lucanus J 21 Aug '08

21 Aug '08

I have encountered the need for an integer data type larger than 64 bits to prevent overflow when doing algebra on 32 bit integer data. I notice that there is mention of a couple proposed boost big int libraries in the archive. Is there a boost library that provides this currently, or is there a library nearing acceptance level quality that I should use? I am not eager to take on a non-boost/non-stl dependency because I intend to submit the geometry library I need this for to boost. Thanks, Luke

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GIL: how to convert an any_image_view to its const equivalent?
by Philipp Reh 21 Aug '08

21 Aug '08

Dear list, I think GIL is not able to convert an any_image_view to its const equivalent or I don't know how to do it. The variant class checks in its constructor if it can hold the given type but it doesn't have a constructor to convert an any_image_view from one to another. Here is a simple piece of code declaring two any_image_views: typedef boost::gil::any_image_view< boost::mpl::vector< boost::gil::rgba8_view_t > > image_view; typedef boost::gil::any_image_view< boost::mpl::vector< boost::gil::rgba8c_view_t > > const_image_view; Now when I try to construct a const_image_view from an image_view I get an std::bad_cast exception. What can I do about it? Cheers, Philipp -- View this message in context: http://www.nabble.com/GIL%3A-how-to-convert-an-any_image_view-to-its-const-… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[1.35] using binary_oarchive instead of text_oarchive
by Alexander Dong Back Kim 21 Aug '08

21 Aug '08

Dear members, I'm trying to use binary_oarchive instead of text_oarchive because I expect using binary may decrease the size of archive compare to using text_oarchive. std::ostreamstream ostr; boost::archive::text_oarvhice oa (ostr); oa & foo; The codes above works fine and I could do deserialization as well without any problem. In this case if I want to use binary_oarchive, what codes should I have to add? Any suggestion or advice will be appreciated. Thank you very much at all time. regards, -- Alexander Dong Back Kim

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[Important] Server outage on Thursday, August 21st
by Doug Gregor 21 Aug '08

21 Aug '08

There will be a server outage on Thursday, August 21st from 8:00AM-9:00AM EDT while we upgrade Boost's Subversion repository to Subversion 1.5. The Boost Subversion repository, Trac, and mailing - Doug

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[extension] Check if basic_type_map is empty
by Boris 21 Aug '08

21 Aug '08

When a library is loaded the return type of shared_library::open() or shared_library::is_open() can be used to detect whether the library was loaded successfully. When shared_library::call() is called the return type can be used to detect whether the exported map function could be called. But is there another function like is_open() which could be called afterwards to check if the map function was called successfully? The datatype basic_type_map only provides get() and no empty(). It would be required to call get() first and operate on the returned std::map type to see if it contains any factories? Boris

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[unordered] Compiler warnings in VC++ 9 SP1
by Boris 21 Aug '08

21 Aug '08

I just replaced a std::map with a boost::unordered_map and got many compiler warnings (not only me as it seems like: http://www.boost.org/development/tests/release/developer/output/RW_WinXP_VC…) Is anyone working already on the code to get rid of the warnings? Boris

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[smart_ptr] make_shared usage
by Daniel Frey 21 Aug '08

21 Aug '08

Hi, I have a question on make_shared. Consider a class which intends to force all instances to be handled via a shared_ptr. I used to do this by putting the ctors into the private section and adding static create()-methods in the public section. Example: class X { private: X( int, double ); public: static shared_ptr<X> create( int i, double d ) { return shared_ptr<X>( new X( i, d ) ); } }; Replacing the returned expression with make_shared<X>( i, d ) wouldn't work, since it requires a public ctor. Is there any solution to this or do I have to make a decision between efficiency and a safe interface for X? Regards, Daniel

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[PATCH: MPL] Compiling with gcc 4.4.0 -std=c++0x
by Chris Fairles 21 Aug '08

21 Aug '08

Due to pre-processor changes in gcc 4.4.0, MPL fails to compile given -std=c++0x or -std=gnu++0x on the command line. The attached patch addresses this issue. This is a works-for-me solution, YMMV. Chris

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Where does make_shared.hpp come from?
by Boris 20 Aug '08

20 Aug '08

I stumbled over boost::make_shared() in Andrey's logging library. I checked the smart pointers documentation at http://www.boost.org/doc/libs/1_36_0/libs/smart_ptr/smart_ptr.htm but couldn't find any reference to boost::make_shared(). The header file make_shared.hpp contains the link http://www.boost.org/libs/smart_ptr/make_shared.html but the webpage doesn't exist either. Is boost::make_shared() not yet documented? Boris

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[log] Questions for Andrey
by Boris 20 Aug '08

20 Aug '08

I've been converting a program from John's logging library to Andrey's logging library. I have to continue playing around with Andrey's library but in the moment I prefer it over John's library. I can't say really that this or that is better - it's more the overall handling of Andrey's logging library which feels more natural for me. Maybe it's also Andrey's documentation which is rather good (the definitions and design overview really help to understand the big picture before you dive into all the details). I've some questions though for Andrey: * Where is the connection between a source and a sink? In the basic_usage example there are two sinks registered (console and file). There is then one source created which is used to log a message. The message is then sent to both the console and the file. But what if I want to use for example two sources and want messages from each source to be sent to a different sink? Do I understand correctly that I need to use attributes somehow and filter records based on attribute values? I guess I would need to add an attribute to each source and set a filter in each sink to make sure only messages with a certain attribute are written? * If I want to format a message and add a timestamp why do I need to write boost::log::formatters::date_time("TimeStamp") and can't write boost::log::formatters::attr("TimeStamp")? Doesn't the attribute value know how to be serialized (or isn't it written to a std::ostream)? If I use boost::log::formatters::attr("TimeStamp") nothing is written to the log file. It's not a problem to use boost::log::formatters::date_time("TimeStamp") of course. But I still wonder why the library can't figure out to write the timestamp if I use boost::log::formatters::attr("TimeStamp"). * I've been reading http://boost-log.sourceforge.net/libs/log/doc/html/advanced/advanced.html#a… a few times but still don't understand why I can't (or shouldn't) instantiate a global logger with "boost::log::sources::logger logger;". I actually did this and everything works (or at least seems to work :). Must the macro BOOST_LOG_DECLARE_GLOBAL_LOGGER really be used when a global logger is created? Maybe I better understand if I ask differently: What is so special about a logger that I need to use a macro to define it globally while I can create for example a global std::string instance without a macro? * By default there is a newline appended to every message written? By the way, looking at the TODO list: I would be very much interested in Windows NT event log support. I'm sure it would also convince more developers to use a logging library as writing texts to files in some fancy ways can also be done without a logging library. :) Boris

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