- Boost-users - lists.boost.org

[range] indirected requirements for custom smart pointer
by Jeff Flinn 21 Jun '12

21 Jun '12

Using boost::adaptors::indirected with a custom templated smart pointer failed compilation due to missing MyCustomSmartPointer::element_type typedef. Indeed supplying this typedef, all compiles and tests run. Is this the canonical approach to making a compatible pointer type usable with range? Is this specific to range only? Will this make my custom smart pointer 'more' compatible with other boost/std facilities? Thanks, Jeff

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Re: [Boost-users] Boost Program Options: Any way to have variable number of "objects" each with parameters?
by Charles Mills 21 Jun '12

21 Jun '12

Here is what I have come up with. Any feedback? I first thought of something like this: CircleRadiuses= 4 7 3 . It's okay for objects with only one value (like Circles) but clumsy and unintuitive for objects with more than one parameter like RectangleHeights= 5 3 7 . RectangleWidths= 10 4 16 . Although I would like to support "any number" of objects, the reality is that a likely number is three or four, so restricting it to a maximum of nine should not be a problem. So here is my plan. Something like [Rectangle1] Height=5 Width=10 [Rectangle2] Height=3 Width=4 and so forth through Rectangle9. Same sort of deal for Circle1 through 9. (I think counting from 1 is more user-friendly for people who are not C programmers.) So, any feedback? Any better way to solve this problem? Charles From: Charles Mills [mailto:charlesm@mcn.org] Sent: Wednesday, June 20, 2012 6:20 PM To: 'boost-users(a)lists.boost.org' Subject: Boost Program Options: Any way to have variable number of "objects" each with parameters? I really like the Boost Program Options library. I've used it for one program now with great effect and I'd like to use it for another, but can't figure out how to structure what I need to do so that Boost PO could handle it. I am solely interested in the ".ini file" for this - command line is irrelevant. The problem is "how does a program allow the specification of a variable number of 'objects' each of which has parameters of its own?" Here is a hypothetical program that exemplifies the problem. Suppose a program were going to create multiple geometric shapes of some sort. An ideal (unsupported by PO) .ini file might look like rectangles=3 rectangle[0].width=5 rectangle[0].height=10 rectangle[1].width=3 etc. circles=2 circle[0].diameter=4 etc. Can anyone suggest a way to accomplish this with Boost PO? I'm real flexible on what the .ini file might look like so long as it solves the problem and is reasonably explicable to a user. (No need for it to look almost like the above.) Thanks, Charles

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Using Boost ICL for range matching
by Rajalakshmi Iyer 21 Jun '12

21 Jun '12

Hello, I want to know if I can use the boost::icl::interval_set to store a set of integer based intervals like: [100, 200], [50, 600] etc and then find out whether a number like 150 matches any of these intervals? I would greatly appreciate if someone can point me to an example for this kind of operation. Thanks, Raj -- Twitter: @Blismedia <http://twitter.com/#%21/blismobile> BlisMedia 32 Percy Street, London W1T 2DE www.blismedia.com <http://www.blismobile.com/> <http://www.blismobile.com/> [image: Follow on Twitter] <http://twitter.com/#%21/blismobile>[image: Blis Website] <http://www.blismobile.com/> This communication is from Blis Media Ltd, a company registered in England and Wales with registered number 06455773. Its registered office is 32 Percy Street, London W1T 2DE, United Kingdom. This communication contains information that is confidential and may also be privileged. It is for the exclusive use of the intended recipient(s). If you are not the intended recipient(s), please (1) notify info(a)blismedia.com<info(a)blismobile.com> by forwarding this email and delete all copies from your system and (2) note that disclosure, distribution, copying or use of this communication is strictly prohibited. Email communications cannot be guaranteed to be secure or free from error or viruses. All emails sent to or from a Blismobile email account are securely archived and stored by an external supplier. This email does not constitute a contractual agreement; such agreements are in specified contractual or Insertion Order (IO) form only and exclusively contain all the terms to which Blis Mobile Ltd will be bound. To the extent permitted by law, Blis Mobile Ltd does not accept any liability for use of or reliance on the contents of this email by any person save by the intended recipient(s) to the extent agreed in a contract or Insertion Order. Opinions, conclusions and other information in this email which have not been delivered by way of the business of Breeze Tech (UK) Ltd are neither given nor endorsed by it.

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Re: [Boost-users] the problem about boost trim function in multi-thread
by Hu Jing 21 Jun '12

21 Jun '12

>>That should be really easy to test. >>How does your test code perform if you change it to this: >> >>void *TrimNString(void *arg) { >> >> string base ="fdsffdsafdsa"; >> locale loc = locale(); >> for(int i = 0; i != 50000000;i++) >> { >> string str = base; >> trim(str, loc); >> } >> return 0; >> } >> Note also that trim calls the locale to look for whitespace, which is more flexible than your test for " \r\n\t". >> That's probably a significant performance difference, too. I have try you method, But it doesn't work. I don't think that boost trim using the locale cause the problem. In the single thread envoriment, the program has the same running time as the my test. so it does't change the program complexity.

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[preprocessor] Identity function for token concatenation
by Jeremiah Willcock 20 Jun '12

20 Jun '12

Boost.Preprocessor has a macro BOOST_PP_INTERCEPT to eat a numeric value that it is token-concatenated onto. Is there a similar macro that just returns the value? I.e., some BOOST_PP_EMPTY_FOR_CONCAT such that BOOST_PP_EMPTY_FOR_CONCAT ## 3 turns into 3? As with BOOST_PP_INTERCEPT, it only needs to work for small integer values. Is there some other technique I can use for this? I am using it to generate std::get<> invocations in BOOST_PP_ENUM_BINARY_PARAMS. Thank you for your help. -- Jeremiah Willcock

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Building boost 1.34 or above on AIX 5.3 with XLC
by Oscar Gueta 20 Jun '12

20 Jun '12

Hello, I am having a hard time compiling AIX 5.3 with XLC v9 (not gcc). Using the --with-toolset=xlc does not work at all (that toolset is not event recognized). Is there any way to make boost to compile in this platform with this compiler? If so, what would be the steps? Thanks in advance, /Oscar

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Re: [Boost-users] Compilation errors when trying to use range adaptors with C++11 lambdas
by Evan Driscoll 20 Jun '12

20 Jun '12

On 06/20/2012 09:04 AM, boost-users-request(a)lists.boost.org wrote: > 2012/6/20 Evan Driscoll<driscoll(a)cs.wisc.edu>: >> When trying to compile the following: >> >> std::vector<int> v; >> v | boost::adaptors::transformed([] (int x) { return x; }); >> >> I get a bunch of compile errors. If I replace the lambda with a function >> defined normally, it works. > > You must use > #define BOOST_RESULT_OF_USE_DECLTYPE > > C++11 lambda can't apply non decltype-base result_of. Thanks a lot; worked like a charm. Of course, in the interim I figured out that the function will be rather more complicated than I thought so I'm happier with it defined normally, but that'll be good to file away for future reference. :-) Evan

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Wondering if any more doc for Boost Progam Options
by Charles Mills 20 Jun '12

20 Jun '12

Just started using the Boost Program Options library. Great stuff! Thanks! Was wondering if there is any more documentation anywhere? For example, is there any documentation for the various methods that can be passed to .add_options(), like boost::program_options::value()? I just happened to figure out boost::program_options::bool_switch() by chance. (I also had to hack my way through an assert to figure out that the "short" option tag, such as -t in ("sometag,t", . could only be one character.) The tutorial was a great start but the detailed documentation just seems to link to the header files which are largely uncommented. Thanks, Charles

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[BGL] grid_graph, vertex_index and shared_ptr
by Sergey Mitsyn 20 Jun '12

20 Jun '12

Hello, Recently I've found that the vertex_index property map of grid_graph holds a shared_ptr to a graph copy. Is there any reason for it? Actually, other classes which are tied with grid_graph holds it by plain pointer. Switching to it in grid_graph_index_map almost doubled the performance on some of my algorithms. Even copying the graph object by value (which actually holds 5 fields with 3 being small boost::array) still has better performance than using shared_ptr. Maybe it should be switched to plain pointer? -- ------------ Sergey Mitsyn.

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[quickbook]error: libstdc++.so.6: version `GLIBCXX_3.4.15' not found
by Larry Evans 20 Jun '12

20 Jun '12

There's a problem with quickbook on ubuntu using an .so library and that .so library needed a missing GLIBCXX library. The bjam output is in attachment. How do I solve the problem? TIA. -Larry

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