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BGL: graphml caption
by Caligula 18 Jul '09

18 Jul '09

Hi, Does anyone know how to add a caption (in BGL) to the graphml output produced by the following line? write_graphml(cout, g, dpp, true);

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Boost filesystem get_temporary_file()
by Craig Henderson 18 Jul '09

18 Jul '09

I cannot find any function in the Boost.Filesystem library to get a temporary filename. There has been some discussion about this functionality on the lists many years ago - did anything come of this? I need a cross-platform way to do this and was hoping boost would provide it :) Thanks -- Craig Craig Henderson <http://craighenderson.co.uk/> http://www.craighenderson.co.uk http://www.siteupdatenotification.com

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compilation error with mpl transform
by Zachary Turner 18 Jul '09

18 Jul '09

Is the following supposed to work? I feel like I'm missing something obvious: typedef boost::mpl::vector<int, float, double> vec_type; template<template<class T>, class U> struct parameterize { typedef T<U> type; }; template<class T> class wrapper { }; typedef boost::mpl::transform<vec_type, parameterize<wrapper, boost::mpl::_1> > wrapped_vec; When I do this I get compile errors on MSVC 9.0. However if I remove the template template and hardcode T to wrapper in struct parameterize, it works fine.

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Fusion container from MPL typelist?
by Zachary Turner 18 Jul '09

18 Jul '09

Suppose I have a boost::mpl::vector<...> and I want a boost::fusion::vector<...> whose types correspond exactly to the types in the mpl::vector. Is there a simple way to go about this? It seems like all the methods of constructing a fusion vector require me to manually specify the individual types as the parameters to fusion::vector<>.

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[filesystem] support for reading symlinks?
by Nils Krumnack 17 Jul '09

17 Jul '09

Hi all, I was wondering whether there was any support for reading the contents of a symlink in the filesystem library, i.e. the path to the file it points to. I saw that back in 2006 somebody submitted a patch that would (among other things) do this. However the patch seems never to have made it into the main trunk. Of course that is fairly easy to implement that myself, but if there is a standard implementation I'd rather use that. Thanks in advance, Nils

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testing boost cross-compiled
by McLemon, Sean 17 Jul '09

17 Jul '09

Having configured the Boost library for our embedded target, built Boost and tested a few examples successfully we'd like to incorporate Boost into our testing framework. I've a couple of queries, though: 1. When we run the run.py script it checks out a fresh version of Boost from SVN, perhaps clobbering local changes or at least wasting a lot of time before testing. The workaround suggested in the website (http://beta.boost.org/development/running_regression_tests.html) - that is passing "--user=" to the script - doesn't change this. Is there any way to prevent this happening reliably? 2. Any executable we generate will need to be run using our command line simulator (i.e. we might create test.dxe, and run using jitccs532.exe test.dxe), how should I convey this to the test suite? 3. Our simulator does support input redirection via the command line (i.e. $ yes | jitccs532 test.dxe) or command line arguments - does this mean that some of tests won't be usable? - Sean

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[Multi-Index] has_index<BMI,TAG> meta-function
by Dominique Devienne 17 Jul '09

17 Jul '09

I'd like to use enable_if/disable_if with a meta-function that determines whether a given multi-index container has a given tagged index. But I'm not having success writing has_index<BMI,TAG>, even looking at BMI's own index<Tag> meta-function :( Does anyone know how to implement it? Below how I'd like to use it. Thanks, --DD struct ByName {}; template <class BMI> struct VCursor { virtual void filter_by_name(const string& name) { do_filter_by_name(name); } private: void do_filter_by_name( const string& name, typename boost::enable_if<has_index<BMI, ByName> >::type* /*dummy*/ = 0 ) { typedef typename BMI::template index<ByName>::type index_type; ... } void do_filter_by_name( const string& name, typename boost::disable_if<has_index<BMI, ByName> >::type* /*dummy*/ = 0 ) { throw "no name index"; } };

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[multi-index] Key extractor for 1:n relationship?
by Boris Schaeling 17 Jul '09

17 Jul '09

All the key extractors in the documentation of Boost.MultiIndex return one value for an element in a container. Is it somehow possible to use a 1:n relationship between element and value? The documentation uses this container definition (among others): typedef multi_index_container< employee, indexed_by< hashed_unique< const_mem_fun<employee, std::string, &employee::name> > > > employee_set; Let's assume an employee can have more than one name (std::string becomes std::vector<std::string>). Now if someone searches for Tom or John the same employee should be returned by the container. Is this possible? Boris

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Using vectors of ptrs
by Robert Jones 17 Jul '09

17 Jul '09

Hi All Here's a quickie for you.... Given struct A { void a(); }; type std::vector<boost::shared_ptr<A> > VecType; VecType v; for (VecType::iterator i=v.begin(); i != v.end(); ++i ) (*i)->a(); How can I write that as a for_each loop? for_each( v.begin(), v.end(), boost::bind( ????? ) ); Thanks, - Rob. ps I can't use lambda because boost.bind is already used, and the placeholder name collisions just aren't worth the pain.

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Re: [Boost-users] UTF16
by Tan, Tom (Shanghai) 17 Jul '09

17 Jul '09

I have some code that does conversion between UTF16 and MBCSs on Windows only: template<typename FROM, typename TO> struct convert { basic_string<TO> operator()(const basic_string<FROM>& from) { return from; } }; template<> struct convert<wchar_t, char> { string operator()(const wstring& from) { return utf16_to_mbcs(from); } private: string utf16_to_mbcs(const wstring& ws) { if(ws.empty()) return string(); const size_t BUFFER_SIZE = (ws.size() << 1) + 1; shared_array<char> p_mcb(new char[BUFFER_SIZE]); bool has_utf16le_bom = (0xFEFF == ws[0]); int count = ::WideCharToMultiByte( AreFileApisANSI() ? CP_THREAD_ACP : CP_OEMCP, WC_NO_BEST_FIT_CHARS, ( has_utf16le_bom ? ws.substr(1) : ws).c_str(), has_utf16le_bom ? ws.size() - 1 : ws.size(), p_mcb.get(), BUFFER_SIZE, 0, 0 ); return (0 == count) ? string() : string(p_mcb.get(), count ); } }; template<> struct convert<char, wchar_t> { wstring operator()(const string& from) { return mbcs_to_utf16(from); } private: wstring mbcs_to_utf16(const string& s) { if(s.empty()) return wstring(); const size_t BUFFER_SIZE = (s.size() << 1) + 1; shared_array<wchar_t> p_ws(new wchar_t[BUFFER_SIZE]); int count = ::MultiByteToWideChar( AreFileApisANSI() ? CP_THREAD_ACP : CP_OEMCP, MB_PRECOMPOSED, s.c_str(), s.size(), p_ws.get(), BUFFER_SIZE ); return (0 == count) ? wstring() : wstring(p_ws.get(), count ); } }; >Date: Thu, 16 Jul 2009 10:39:31 +0200 >From: plarroy <plarroy(a)promax.es> > >My approach is using std::string, etc. all the time and using UTF-8 >internally, only converting to other charsets when it's needed. >I use IBM icu library and made a boost::iostreams filter to convert >encoding, once it's done takes a lot of complexity away, I use it like: > // setup a conversion from charset to utf-8 > filt_streamb.push(ucnv_filter(charset.c_str(), "utf-8")); > istream is(&filt_streamb); >Perhaps there's interest to push this charset conversion into >boost::iostreams filters examples. >Regards. Robert Dailey wrote: > Oh, I also forgot to mention, I am also using boost::filesystem::path. I > guess this means I need to use wchar_t everywhere (std::wstring, > boost::filesystem::wpath, etc) and just let wxWidgets do the > encoding/decoding? If I don't have to do any encoding/decoding myself, then > there really is no need for a special object. But just in case I would like > to have the encoding/decoding abilities. > > On Sun, Jun 14, 2009 at 12:27 PM, Robert Dailey <rcdailey(a)gmail.com> wrote: > > >> Hi everyone, >> I did a bit of googling to see if Boost 1.39 as any portable support for >> UTF-16 encoded strings, but I did not find any. I'm currently using >> wxWidgets in my application, and I need a decent string object to use. I >> know that wxWidgets has UTF-16 string support through wxString, however I do >> not want to expose this object in my interfaces. I want to remain as >> abstracted away from wxWidgets as possible. Having said that, if someone >> could tell me if there is any existing UTF-16 string support in Boost, I'd >> appreciate it. I did not find anything in the vault, sandbox, or trunk in >> Boost. >> >> If boost has no such string object, could someone give me a head start on >> where to look? Thanks. >>

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