September 2005 - Boost-users - lists.preview.boost.org

Program options
by Paul Giaccone 28 Sep '05

28 Sep '05

In the documentation on program_options (program_options/overview.html), in the section Parsers Component it says "Sometimes it's desirable to specify value as several tokens. For example, an option "--email-recipient" may be followed by several emails, each as a separate command line token. This behaviour is supported, though it can lead to parsing ambiguities and is not enabled by default." This is just what I would like to. However, I haven't found anything in the documentation explaining how to do this. I don't think this can be done using positional options - is this correct? For example, I would like to be able to have command-line options along the lines of: -A 1 2 3 -B hello goodbye and have 1, 2, and 3 stored in a vector of integers associated with the -A flag, and "hello" and "goodbye" in a vector of strings associated with the -B flag. So how do I enable this? Paul Giaccone

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VC++ 7.1 and precompiled header
by Marco Segurini 28 Sep '05

28 Sep '05

Hi VC++ 7.1 compiler uses the stdafx.h to create a precompiled headers file. I usually put all the boost headers in stdafx.h but sometime strange compiler errors are reported. If I move some headers out of stdafx.h all works fine. I like to know if there is a list of boost headers that cannot be put in the stdafx.h TIA Marco.

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how to download a single library
by Stas Khirman 28 Sep '05

28 Sep '05

Hi, Is the way to extract one specific library ( smart_ptr in my case) from complete BOOST source tree? I need to use only smart_pointers, but undirtunately keeping a full BOOSt treen is too heavy for my CVS server. Are boost libraries heavy interrelated each with another? Regards Stas

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boost::is_complex
by Edward Grace 28 Sep '05

28 Sep '05

Dear all, Can someone add an is_complex<T>::value trait to type_traits.hpp ::boost::is_complex<T>::value trait to type_traits.hpp I have found myself having to do this frequently. It strikes me that for templated scientific codes it is a common requirement. Below is my implementation, please feel free to add it. I should probably inform the maintainer as well, John Maddock but there is no obvious way of contacting him via the boost site. namespace boost { /** * @brief Default trait for determining if a type is complex at * compile-time. * * If the supplied template parameter type is not a std::complex<> * then this struct is instantiated and the ::value enum will be 0 * at compile time. * * See also boost::is_float and associated in * boost/type_traits.hpp */ template <typename T> struct is_complex : ::boost::mpl::false_{}; /** * @brief Overloaded trait for std::complex<> to determine if a * type is complex at compile-time. * * If the supplied type is std::complex<double> or similar this * overloaded struct is instantiated and the ::value enum will be * 1 at compile-time. * * See also boost::is_float and associated in * boost/type_traits.hpp */ template <typename T> struct is_complex<std::complex<T> > : ::boost::mpl::true_{}; } -ed -- Dr. Edward Grace Photonics Group, Physics Department Blackett Laboratory Imperial College SW7 2BW t: 020 759 47719 e: ej.grace(a)imperial.ac.uk w: http://ptweb.op.ph.ic.ac.uk/~graceej

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[regex] Bug: negative lookahead does not work in 1.33.0
by Rob Willis 28 Sep '05

28 Sep '05

The following regex should match any document that IS NOT a pdf file: .*[.](?!pdf$).*$ This regex should match: Mynotes.doc It should fail on: Myinfo.pdf However, the above regex returns true on both using boost 1.33.0. But positive lookahead works fine: .*[.](?=pdf$).*$ Above regex correctly matches only documents ending in .pdf . Can anyone confirm this is a bug? Thanks, -Rob

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[iostreams] interrupted reads / writes
by Marcus Alanen 28 Sep '05

28 Sep '05

Hello, I have been toying with a framework for process management. I have opted to catch SIGCHLD in my signal handler to handle child processes. However, boost::iostreams does not seem to recognize system calls which are interrupted, and throws exceptions. Witness ./libs/iostreams/src/file_descriptor.cpp: errno = 0; std::streamsize result = BOOST_RTL(read)(pimpl_->fd_, s, n); if (errno != 0) throw detail::bad_read(); return result == 0 ? -1 : result; if ::read fails with errno == EINTR, a bad_read will result. This is unfortunate, as caught SIGCHLD signals will result in spurious errors, as the following strace shows: ... read(9, 0x95d83ac, 4096) = ? ERESTARTSYS (To be restarted) --- SIGCHLD (Child exited) @ 0 (0) --- waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], WNOHANG) = 2407 sigreturn() = ? (mask now []) write(2, "terminate called after throwing "..., 48) = 48 write(2, "std::ios_base::failure", 22) = 22 write(2, "\'\n", 2) = 2 write(2, " what(): ", 11) = 11 write(2, "bad read", 8) = 8 write(2, "\n", 1) = 1 ... As I understand it, boost was going to use ::read(), but the SIGCHLD got in between, resulting in a an exception being thrown. I realize that boost::process is not up and running yet, so this might be a usage conflict of posix & boost. Can somebody please enlighten me what the usage pattern here should be? Thanks in advance, Marcus

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Re: [Boost-users] how to download a single library
by Sohail Somani 28 Sep '05

28 Sep '05

You can use bcp then import it into your tree. The link escapes memory though. Might want to google it. > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Stas Khirman > Sent: Monday, September 26, 2005 11:32 PM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] how to download a single library > > > Hi, > > Is the way to extract one specific library ( smart_ptr in my > case) from complete BOOST source tree? I need to use only > smart_pointers, but undirtunately keeping a full BOOSt treen > is too heavy for my CVS server. Are boost libraries heavy > interrelated each with another? > > Regards > Stas > > > > > > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Problems non intrusively serializing template inheritance classes, boost 1.33
by Pyush Agrawal 27 Sep '05

27 Sep '05

Hi, I am relatively a new to Boost serialization classes. I am trying to serialize a derived template class. template<class T> class base {}; tempate<class T> class derived : public base<T> {}; I am trying to serialize 'derived' and have tried many different things. I am unable to serialize the inherited template classes. For some reason the code calls (1) 'derived::Serialize' (2) 'base::Save' and never executes 'derived:: Save' and doesnot serialize the 'derived' object properly. I am attaching the source code (SerializeTemplates.cpp) and the output( output.txt) of the program. I am using MSVC7.1, debug mode, Boost 1.33, Spirit 1.8 It will be great, if somebody could point out what I am doing wrong. Thanks, Pyush

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[function] Tiny documentation error?
by Stuart Dootson 27 Sep '05

27 Sep '05

I noticed that the documentation for boost::functionN::swap has a parameter type of "const functionN&". Shouldn't that be "functionN&" (i.e. non-const rather than const reference)? Stuart Dootson

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Building boost for WinCE (eVC4)
by David Balazic 27 Sep '05

27 Sep '05

Hi! Did anyone succeed building boost with MS embedded C++ 4 for WinCE 4.2 (x86) platform ? I see no TOOLS is defined for "evc4". Help ! David Balazic PS: I posted this first over http://groups.google.com on friday, but it did not appear on the list, so I subscribed and re-posted it. --------------------------------------------------------------------- http://noepatents.eu.org/ Innovation, not litigation ! --- David Balazic mailto:david.balazic@hermes.si HERMES Softlab http://www.hermes-softlab.com Zagrebska cesta 104 Phone: +386 2 450 8851 SI-2000 Maribor Slovenija --------------------------------------------------------------------- "Be excellent to each other." - Bill S. Preston, Esq. & "Ted" Theodore Logan ---------------------------------------------------------------------

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