March 2011 - Boost-users - lists.preview.boost.org

How to skip a sub-directory with filesystem3::recursive_directory_iterator in case of exception?
by Tan, Tom (Shanghai) 30 Mar '11

30 Mar '11

I am iterating a mapped network drive under windows, K:\, under which are 3 sub directories A, B, C, where K:\B is only visible itself but cannot be iterated into due to group policy. With code below: boost::system::error_code ec; for (recursive_directory_iterator itr(root, ec), itr_end; itr!=itr_end; itr++) { ... } It throws in itr++ when itr->path() == "K:\B". I would like to skip going into k:\B and go on with K:\C, so I code like this: for (recursive_directory_iterator itr(root, ec), itr_end; itr!=itr_end; ) { ... ; itr.increment(ec); } It does not solve my problem, but introduces one more: itr will never equal to itr_end even though all item are iterated over, and this happens for any normal folder such as K:\A. thus never get's out of for loop until the internal vetor<directory_iterator>::operator+=() asserts. Again, I tried something like below. for (recursive_directory_iterator itr(root, ec), itr_end; itr!=itr_end; ) { ... ; itr.increment(ec); if(ec) itr.pop(); } This time itr.pop() assertion fails because "pop() on recursive_directory_iterator with level < 1" Anybody got some advice? Thanks.

1 0

GSOC 2011
by Rafael González 30 Mar '11

30 Mar '11

Hello I would like to participate with Boost in GSOC 11. I have some ideas about arbitrary precision and a Monte Carlo simulation framework. I've already seen the time line and I know that applications begin today, so, should I prepare it right now or I we have time to discuss it with someone. Thanks

3 3

Matrix initialization in uBLAS
by Oscar Vargas 30 Mar '11

30 Mar '11

It's the first time I use uBLAS, and I want to know the right way to initialize a matrix. Example: | 3 2| M = | 1 5| | 3 4| How can I create such a matrix? For example, in Matlab, you can type: >> M = [3, 2; 1, 5; 3, 4] I haven't found documentation for something as simple as that!!! I need help!

2 1

Re: [Boost-users] [context review] Review starts today, Mars 21st 2011
by Vicente BOTET 29 Mar '11

29 Mar '11

> Message du 21/03/11 02:21 > De : "Nat Linden" > A : boost-users(a)lists.boost.org > Copie à : > Objet : Re: [Boost-users] [context review] Review starts today, Mars 21st 2011 > > On Sun, Mar 20, 2011 at 8:18 PM, Vicente BOTET wrote: > > > The review of Oliver Kowalke Context library starts today Mars 21st 2011, and will end on Mars 30th. > > > > I really hope to see your vote and your participation in the discussions on the Boost DEVELOPMENT mailing lists! > > WARNING !!!!!!!!!!!!! Only on the Boost DEVELOPMENT mailing lists > > :-( > > I am not presently on the development mailing list; I am reluctant to > register because keeping up with the boost-users list already takes a > surprising amount of my time. > > I have opinions and a bit of experience with the topic area of this > library, and I was planning to submit a review. But I feel rebuffed. > > Perhaps I could submit a review on this list and have you, the review > manager, helpfully forward it to the development list? Hi Nat, I'm really sorry to miss your post. I should read the Users ML before , but as you can see I'm used to read only the dev ML as you are used to read only the user ML. I think that I should change my habits as Boost.Chrono and Boost.Ratio should be released in the next release :) As Michael has explained it is difficult for the review manager, the author and the other reviewers to follow the review in two ML. I hope you can understand that. As Vladimir said you can post the review to the dev ML and follow up the review using some archives as nabble boost dev for example. If you are yet interested in making a review I will accept it on this ML exceptionally as the review is almost finished. I will forward to the dev ML. Waiting for your review, Vicente

1 0

Re: [Boost-users] [all libs] compatibility
by Pace, Antony [Harman Pro Group UK] 29 Mar '11

29 Mar '11

I am using boost::asio on a small FPGA core running NIOS and uCos and having problems. After reading documentation I now understand that asio is only implemented for a number of platforms; albeit the bigger platforms. I see other messages on this forum about platform compatibility and am getting more and more disillusioned with Boost. I thought the whole point was that boost libraries only needed a compliant compiler. I understand that for TCP/IP and timers there needs to be some interoperability with the underlying operating system. I understand for example that timers can plug into posix or Windows timers but I can't understand why the boost libraries themselves have #ifdef WINVER statements in them. I could understand that to run libraries such as asio on my OS I need to implement a set of functionality and can imagine those being available for popular OSes such as Windows and Linux separately, ie outside the scope of Boost. Would it not be possible to have well defined OS interfaces for all libraries that are OS dependent and would that not be more in the spirit of Boost and ultimately C++ and STL? Many thanks for your thoughts. Ant [cid:image001.png@01CBEE31.17904490] Cranborne House, Cranborne Road, Potters Bar, Herts, EN6 3JN Phone: +44 1707 668025 Email: antony.pace(a)harman.com Skype: antony.pace.harman Web: www.harman.com ANTONY PACE Senior Software Engineer Soundcraft Studer R&D Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorised review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

2 1

[context review] Review ends tomorrow Mars 30st 2011
by Vicente BOTET 29 Mar '11

29 Mar '11

Hi all, The review of Oliver Kowalke Context library ends tomorrow Mars 30th. If you have taken already a look at the library, please make a review even if you can do only a short one. Let me know if you think you need more time to do a deeper review, so I can see with Oliver and the review wizards if we can extend the library. Best regards, Vicente Review Manager Boost.Context is a basic building block library that is used for more higher abstractions. It is used by Boost.Fiber, Boost.Tasklet and Boost.Task from the same author. I really hope to see your vote and your participation in the discussions on the Boost DEVELOPMENT mailing lists! WARNING !!!!!!!!!!!!! Only on the Boost DEVELOPMENT mailing lists Please use [context review] as prefix of your post to make easier the review follow up. You can download a frozen version for the review from the Vault, TinyURL: http://tinyurl.com/5r77rel or The documentation is available directly here: http://ok73.ok.funpic.de/boost/libs/context/doc/html/ --------------------------------------------------- About the library: Boost.Context provides a possibility to switch between different user-level context and is intended to be the basis for a higher abstraction like coroutine and fiber. A user-level context represents the current execution state, including all registers and CPU flags, the instruction pointer, the stack pointer. boost::context encapsulates such a user-level context and is able to store/restore its associated user-level context. This allows multiple execution paths running on a single thread using a sort of cooperative scheduling (in contrast a thread is preemptively scheduled) - the running boost::context decides explicitly when its yields to allow another boost::context to run (user-level context switching). A context can only run on a single thread at any point in time but may be migrated between thread. A context switch between threads costs usually thousands of CPU cycles on x86 compared to a user-level context switch with few hundreds of cycles. Boost.Context differes to setjmp()/longjmp() in the fact that the C99 standard does not require that longjmp() preserves the current stack frame, e. g. jumping into a function which was exited via a call to longjmp() is undefined. Boost.Context allows to select the mechanism provided by the operating system (ucontext on UNIX, Windows Fibers on Windows) or a faster implementation provided by this library (fcontext using assembler). --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain?

1 0

[enable_if] How to enable a constructor
by Michael Kaes 29 Mar '11

29 Mar '11

Hi all, I am playing around with enable_if and I want to create a constructor switch. The code is the following: ------------------------------------------------ struct NullType{}; struct TestType{}; struct NonNull{}; template<typename T, typename U = NullType> struct TemplateStruct { TemplateStruct(int i, typename boost::enable_if<boost::is_same<U, NullType>, void* >::type dummy = 0) { std::cout << "One Param == " <, void* >::type dummy = 0) { std::cout << "Two Param == " <(1); TemplateStruct<TestType,NonNull>(1,2); return 0; } ------------------------------------- I want that the first Ctor is only available when a NullType is passed in and if not that the second one is available but not the first. I don't want to do a class specialization because the class is rather big and extracting all the methods to a common class would be difficult. So how can I reuse the template parameter U for the Ctors enable_if? Or is this simply not possible? Regards, Michael

4 3

Ref: FW: Platform Compatibility (Shahriar, Khandaker (CONT))
by Avi Bahra 29 Mar '11

29 Mar '11

>Good Afternoon, >Please verify if Boost Library is compatible with HPUX 11.x or AIX? Please note there is not a single boost library. HPUX --------- Boost does not officially support HPUX. However I have managed to build boost successfully with version 1.45 using HPUX compiler vapp, with the following compiled libraries: boost_serialization boost_system boost_thread boost_test boost_test_monitor boost_program_options boost_filesystem boost_datetime boost_python and use the following header only libs: smart pointer, bind, ASIO, lexical_cast, utility, lambda spirit classic Note ASIO < 1.45 was broken, than has now been fixed in 1.45 Occasionally I have had to hack boost to get it to compile. Up to boost 1.38 I used gcc on HPUX. AIX ----- All of the libraries mentioned above should work fine on v11.1 c++ compiler However please note: the boost serialisation is broken in release mode, and has been for quite a while. Also there are problems with spirit.qi You need to look at each library individually to see if it works for you. Best regards, Ta, Avi

1 0

[Fusion] Assignement from adapted struct to tuple
by Samuel Debionne 29 Mar '11

29 Mar '11

Hello all, While I managed to assign an adapted structure to a fusion vector, I fail to assign the same structure to a legacy tuple. The doc doesn't mention the assignement operator between two sequences, but I though it would work. Am I missing something ? #include <boost/fusion/include/vector.hpp> #include <boost/fusion/include/adapt_struct.hpp> #include <boost/fusion/include/boost_tuple.hpp> struct my_struct { double a; int b; char c; }; BOOST_FUSION_ADAPT_STRUCT( my_struct, (double, a) (int, b) (char, c)); my_struct src; boost::fusion::vector<double, int, char> dest1 = src; //OK boost::tuple<double, int, char> dest2 = src; //Fails Samuel

2 2

FW: Platform Compatibility
by Shahriar, Khandaker (CONT) 29 Mar '11

29 Mar '11

Good Afternoon, Please verify if Boost Library is compatible with HPUX 11.x or AIX? Thx! Khan 804-284-7201 </pre> The information contained in this e-mail is confidential and/or proprietary to Capital One and/or its affiliates. The information transmitted herewith is intended only for use by the individual or entity to which it is addressed. If the reader of this message is not the intended recipient, you are hereby notified that any review, retransmission, dissemination, distribution, copying or other use of, or taking of any action in reliance upon this information is strictly prohibited. If you have received this communication in error, please contact the sender and delete the material from your computer. </pre>

3 3