September 2013 - Boost - lists.preview.boost.org

proposal for metafunction mpl::eval
by klaus triendl 12 Sep '13

12 Sep '13

Hi, I'm not so much into meta-programming, so I'm not sure whether there's already an alternative available. Nevertheless I'd like to propose a new metafunction that simply evaluates its argument: template<typename F> struct eval: F::type {}; I've found it somehow useful because it avoids syntactical sugar when specifying a condition to be evaluated for eval_if: eval_if< eval<apply<UnaryF, Arg>>, F1, F2 >; instead of writing: eval_if< … [View More]

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[interprocess] Different processes accessing shared memory in different locations
by Tom Sanham 11 Sep '13

11 Sep '13

Hi Our application has the following scenario using Boost V1.0.52: 1) Process A writes to boost interprocess shared memory. The files appear at C:\ProgramData\boost_interprocess\... 2) Process A launches Process B 3) Process B attempts to read from shared memory but fails. It is attempting to read from: C:\Users\<username>\AppData\Local\Temp\boost_interprocess\... This failure only occurs on one single Windows 8 64 bit machine out of many we have tested. On all other machines, the … [View More]

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[asio] Mixing streambuf-based async_read and async_read_until
by Gavin Lambert 11 Sep '13

11 Sep '13

I was tracing through some code today (using Boost.Asio 1.53) and noticed something that seems a little odd to me. Given a boost::asio::streambuf that already contains data (typically from a previous read), the async_read_until operation will check the buffer first to see if it can find the specified delimiter already, and will only fetch more data from the stream if it needs to. It does appear to perform at least one async_read_some per async_read_until call, but this will be a zero-… [View More]

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Incompatible Boost license file in boost.container
by Philip Bennefall 10 Sep '13

10 Sep '13

Hi all, I was looking at boost.container, and found that boost/container/deque.hpp has similar problems as boost/detail/endian.hpp had before that was fixed. Parts of deque.hpp seem to be covered by a license that is not compatible with the Boost software license. I quote: // Copyright (c) 1996,1997 // Silicon Graphics Computer Systems, Inc. // // Permission to use, copy, modify, distribute and sell this software // and its documentation for any purpose is hereby granted without fee, // … [View More]

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Re: [boost] [cpo-proposal] presentation of the idea
by Santiago Tapia 10 Sep '13

10 Sep '13

Hi, I have working in the implementation of the cpo library, so I keep working and I expect to make a formal proposal within 2 or 3 months, and meanwhile I will try my best to answer mails. > Date: Wed, 28 Aug 2013 11:18:03 +0400 > From: Andrey Semashev <andrey.semashev(a)gmail.com> > The storage strategy does not mandate the interface of the container. > unordered_set/map are implemented as a number of buckets (i.e. > single-linked lists), yet they provide sequence … [View More]interface with an > additional ability to iterate within a single bucket. I don't see why a > similar approach couldn't be taken in your container. I will not provide the classifier container with a push_back or push_front method, instead I will use insert, I suppose it is just about the meaning of sequence, I expect a sequence to keep an order on items while container means just a collection of items in not a particular order. On the other hand I will provide a way to iterate over a "single bucket". Actually, I have been working on benchmarking and that seems to be the better option to iterate over the classifier because it reduces the number of virtual method calls in the iteration. I also will provide a const random access iterator and some other utilities to access a particular item in the container. > > You can't create std::multiset<shape> but you can create > boost::intrusive::multiset<shape>. The reason for that is that > std::multiset attempts to allocate storage for shape, while > boost::intrusive::multiset doesn't, leaving this to the user. This allows > you to insert any objects derived from shape to the single > boost::intrusive::multiset and work with this container pretty much the > same way you would with std::multiset. You can even insert the very same > object in multiple containers if you need to. I recommend you to have a > look at Boost.Intrusive, it is a truly amazing library. The interface for my library needs to be far more simple than the interface in Boost.Intrusive, but I will consider that option to implement the details. Up to now, I am only using std containers to avoid dependencies, but I will consider other options to optimize speed and size performance. [snip] About "polymorphic vector", that is, a container that stores different types contigously, I should say that the interface needs to be as easy as in the classifier, so I will discard solutions that needs any requirement to objects apart from being copyable, default constructive or the like. I will try to develop a prototype from Larry Evans' example (with his permission). But because I am not an expert on alignment and memory optimization, I will try to use something "more standard", actually I am going trying to use the allocator to compute the "right" address to place an object of a given type that is greater that a "free" memory pointer. In that way, I also expect to take advantages of allocator such as tbb cache aligned allocator. Again, thank you all for your comments. Regards, Santiago -- ESCUELA TÉCNICA SUPERIOR DE INGENIEROS INDUSTRIALES UNIVERSIDAD POLITÉCNICA DE MADRID Santiago Tapia Fernández | DEPARTAMENTO DE AUTOMÁTICA, INGENIERÍA ELECTRÓNICA E INFORMÁTICA INDUSTRIAL José Gutiérrez Abascal, 2 | 28006 Madrid TEL +34 91 336 4266 E-MAIL stapia(a)industriales.upm.es www.industriales.upm.es [View Less]

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Re: [boost] [cpo-proposal] presentation of the idea
by Santiago Tapia 10 Sep '13

10 Sep '13

> Date: Mon, 09 Sep 2013 11:57:43 -0500 > From: Larry Evans <cppljevans(a)suddenlink.net> > >> But because I am not an expert on alignment and memory >> optimization, I will try to use something "more standard", actually I am >> going trying to use the allocator to compute the "right" address to place >> an object of a given type that is greater that a "free" memory pointer. >> In that way, I also expect to take advantages of allocator such as >&… [View More]

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[PREPROCESSOR] Possible improvement for BOOST_PP_VARIADIC_SIZE
by Brent Lewis 10 Sep '13

10 Sep '13

Currently, BOOST_VARIADIC_SIZE() evaluates to 1. Based on http://gustedt.wordpress.com/2010/06/08/detect-empty-macro-arguments/ it can be improved to return 0 for an empty argument list.

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Quid pro quo for Boost peer review manager
by Niall Douglas 09 Sep '13

09 Sep '13

Dear Boost Devs, GSoC 2013 ends on 23rd September, and myself and Paul expect that Boost.AFIO will be ready for peer review at around that time after finishing the following features from your voting at http://boostafio.uservoice.com/: (i) Directory Monitoring (ii) Asynchronous Directory Enumeration (iii) Parts of Improved formal closure execution engine support based on the latest updated papers in the Sept WG21 mailing N3721 and N3731. It seems unfair to ask for someone to volunteer … [View More]

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[Thread] possible bug in Move emulation "portable interface"
by Gavin Lambert 09 Sep '13

09 Sep '13

I tried submitting this via Trac but for some reason it was convinced that my bug report contained spam, while refusing to tell me what part it was objecting to, and also refusing to give me a captcha or anything to convince it otherwise. Anyways: Bug 1: the Boost.Thread documentation and release history indicate that BOOST_THREAD_VERSION==3 is the default since v1.52. As far as I can tell this has never been true in any released version; the latest code still has ==2. (I found a … [View More]

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Fwd: Re: [atomic] atomic<int>::is_lock_free() returns false on iPad 4 (armv7s)
by Tim Blechmann 09 Sep '13

09 Sep '13

-------- Original-Nachricht -------- Betreff: Re: [boost] [atomic] atomic<int>::is_lock_free() returns false on iPad 4 (armv7s) Datum: Mon, 09 Sep 2013 15:49:06 +0100 Von: Phil Endecott <spam_from_boost_dev(a)chezphil.org> An: Tim Blechmann <tim(a)klingt.org> Hi Tim, (My Boost list subscription is temporarily broken; feel free to forward this if you want.) Tim Blechmann wrote: >>> boost:atomic<int>::is_lock_free() returns false on iPad 4 (armv7s) but >&… [View More]

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