July 2012 - Boost - lists.preview.boost.org

Re: [boost] [type_erasure] [docs]contrast with boost::any
by Larry Evans 23 Jul '12

23 Jul '12

On 07/23/12 15:37, Larry Evans wrote: > On 07/18/12 00:13, Lorenzo Caminiti wrote: >> Hello all, >> >> *** The review of Steven Watanabe's proposed Boost.TypeErasure library >> begins on July 18, 2012 and ends on July 27, 2012. *** >> > The page: > > http://steven_watanabe.users.sourceforge.net/type_erasure/libs/type_erasure… > > says: > > x is approximately equivalent to a boost::any > > however, it doesn't say how te::any differs from boost::any. > > The attached shows that a boost::any can change it's > type, and, as such, is somewhat like boost::variant. > However, te::any, once it's created, cannot change > it's type, AFAICT. At least that's what the > attached code indicates when compiled with: > > #define SHOW_TE_FIXED_TYPE > A simplified version of that code (which doesn't require demangled_type_name), is attached. The attached also suggests that, when multiple placeholders are in the concept, the unary any *requires* a binding argument. This is shown by trying to compile the attachment with: #define SHOW_BINDINGS_MUST_BE_COMPLETE In contrast, the example here: http://steven_watanabe.users.sourceforge.net/type_erasure/libs/type_erasure… shows no binding is needed because the only placeholder in the concept is the default, _self. HTH. -regards, Larry

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[Review Request] array
by Brian Smith 23 Jul '12

23 Jul '12

Hi All, Based on the assumption that, almost no feedback is good feedback, I'd like to submit the array class for review. The requisite files are hosted at, https://github.com/BrianJSmith/Array Comment: The array class is a C++11 compatible implementation of static multidimensional arrays. Kind Regards Brian

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[TypeErasure] Forward constructors and binded types
by Vicente J. Botet Escriba 23 Jul '12

23 Jul '12

Hi,, In the example from the doc typedef mpl::vector< copy_constructible<_a>, copy_constructible<_b>, copy_constructible<_c>, constructible<_a(const _b&, const _c&)> > construct; std::vector<double> vec; int i = 10; double d = 2.5; tuple<construct, _a&, _b, _c> t(vec, i, d); any<construct, _a> v(get<1>(t), get<2>(t)); I don't see which type is constructed and stored in v and how this type is given. That is I don't see how _a is binded. Could you help me? Best, Vicente

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[TypeErasure] BOOST_TYPE_ERASURE_MEMBER
by Julien Nitard 23 Jul '12

23 Jul '12

Hi Steven, all BOOST_TYPE_ERASURE_MEMBER is only mentioned in the reference, it could be useful to add it to the tutorial: I guess that most user concepts will start from member functions of a given type. A sample on how to specialize it for types not having the said member function would be also welcome. Finally, why did you choose not to include the member's signature in the macro ? Isn't this giving the way for hard to find mistakes ? Regards, Julien

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[website] Server problems
by Daniel James 23 Jul '12

23 Jul '12

Hello, As you might have noticed, many of the php based pages were down this morning. The cause appears to be that the directory '/home/grafik/www.boost.org/' didn't have read and execute permissions for all, so php couldn't read a file within it. I fixed it by giving read permission - nothing in that directory is private so I don't think that will be a problem. Hopefully that's okay? I don't like messing round with these things too much, as I don't know the details about the setup. Does anyone have any idea what changed to cause this issue? Maybe an upgrade or configuration change? Could it use group permissions before but can't now for some reason? Or perhaps something accidentally changed the permission on the directory? It'd be useful to understand what happened. Daniel

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[spirit][phoenix] Spirit v2 conflicts with Phoenix v3
by Andrey Semashev 23 Jul '12

23 Jul '12

Hi, Recently I tried to port my code to Boost.Spirit v2 and Boost.Phoenix v3. After including the following headers: #include <boost/phoenix/core.hpp> #include <boost/spirit/include/qi_core.hpp> I got the following error: In file included from ./boost/spirit/home/phoenix/core.hpp:13:0, from ./boost/spirit/include/phoenix_core.hpp:14, from ./boost/spirit/home/support/make_component.hpp:15, from ./boost/spirit/home/support/meta_compiler.hpp:20, from ./boost/spirit/home/qi/domain.hpp:15, from ./boost/spirit/home/qi/parser.hpp:15, from ./boost/spirit/include/qi_core.hpp:16, from libs/log/src/text_file_backend.cpp:51: ./boost/spirit/home/phoenix/core/actor.hpp:46:16: error: redefinition of ‘struct boost::phoenix::detail::error_expecting_arguments’ ./boost/phoenix/core/actor.hpp:41:16: error: previous definition of ‘struct boost::phoenix::detail::error_expecting_arguments’ ./boost/spirit/home/phoenix/core/actor.hpp:65:12: error: redefinition of ‘struct boost::phoenix::actor<Expr>’ ./boost/phoenix/core/actor.hpp:161:12: error: previous definition of ‘struct boost::phoenix::actor<Expr>’ I take it the problem is that Boost.Spirit always include Phoenix v2 which causes name clashes with v3. Is this a known problem? Shouldn't Boost.Spirit include Phoenix v3 headers instead? I can see v3 redirects includes to v2 if BOOST_PHOENIX_USE_V2_OVER_V3 macro is defined (BTW, there's an error in boost/phoenix/stl.hpp: BOOST_PHOENIX_USE_V2 macro is checked instead). This happens in the release branch.

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[TypeErasure]_self
by Markus Werle 23 Jul '12

23 Jul '12

Hi Steven, In [docs]/type_erasure/libs/type_erasure/doc/html/boost_typeerasure/feedback.html you ask for feedback: I would be perfectly happy with _ instead of _self. You would be in sync with the folks that wrote C# Reactive Extensions (http://msdn.microsoft.com/en-us/data/gg577611) who have the convention that _ stands for "unused", which it is here, too. To me constructible<_(const std::string&)> reads fine. Markus

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[website][unordered] Patches on release notes.
by Daniel James 22 Jul '12

22 Jul '12

Hi, There's a fairly serious bug in Boost.Unordered in 1.50 so I wanted to make a patch available. I've added it to the release notes, at the top so it's quite visible, you can see it here: http://www.boost.org/users/history/version_1_50_0.html I'm emailing about this, partly to bring the patch to people's attention and partly to find out what you think of using the release notes this way. Daniel

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[asio] windows::basic_stream_handle
by Daniel Larimer 22 Jul '12

22 Jul '12

Is there a reason why basic_stream_handle does not/can not implement bytes_available() or non_blocking() but can implement sync and async methods? Dan

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Container docs: 404 image
by Olaf van der Spek 22 Jul '12

22 Jul '12

Hi, Page A has a link to image B which doesn't exist. A http://www.boost.org/doc/libs/1_50_0/doc/html/container/non_standard_contai… B http://www.boost.org/doc/libs/1_50_0/doc/html/images/stable_vector.png -- Olaf

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