- Boost - lists.boost.org

[range] Performance benchmarks?
by Beman Dawes 02 Feb '12

02 Feb '12

A question came up in a long bikeshed discussion on a C++ committee mailing list as to the performance of range based interface versus a begin/end iterator interface (I.E. traditional STL interface) to the same algorithms. Out of curiosity, I checked the Boost.Range docs, but didn't see any performance measurements. It might encourage potential users to take the leap if the Boost.Range "Introduction" page made some mention of performance implications for use of the Boost library. The intro gives a "Push the even values from a map in reverse order into the container target" example: // Assume that is_even is a predicate that has been implemented elsewhere... push_back(target, my_map | map_values | filtered(is_even()) | reversed); Are there any benchmarks available for this? What does the straight STL version of the code look like? --Beman

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[1.49] No description about Boost.Heap in Library Documentation page
by Michel Morin 02 Feb '12

02 Feb '12

There is no description about Boost.Heap at http://www.boost.org/doc/libs/1_49_0_beta1/ Ditto for "trunk/boost/libs/libraries.htm" Regards, Michel

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[1.49.0] New libraries in 1.49.0?
by Beman Dawes 02 Feb '12

02 Feb '12

What are the new libraries in 1.49.0? --Thanks, --Beman

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[interprocess] utf8 file names in memory mapped files
by Thorsten Ottosen 01 Feb '12

01 Feb '12

Hi Ion, It would be great if we could support utf8 encoded file names on windows too. I guess all it requires is a utility function that converts from utf8 to utf16 on windows. Such a function is avaiable in the windows API, and I can supply it. kind regards Thorsten

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[1.49.0] Beta 1 release candidates available
by Beman Dawes 01 Feb '12

01 Feb '12

Release candidate files for 1.49.0 beta 1 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. Thanks, --The release managers --PS: I downloaded the 7z version, and it build without errors on Win7/VC++ Express 2010 sp1

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[1.49.0] Branches/release open for bug fixes and documentation updates
by Beman Dawes 01 Feb '12

01 Feb '12

branches/release is now open for bug fixes and doc updates, without need to ask for a release manager's permission. It will remain open until Monday, February 13th. The final release is scheduled for February 20th. The hope is that this somewhat longer beta period will allow time to fix more bugs that surface during the beta period. --Beman

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[local_function] ready
by Lorenzo Caminiti 01 Feb '12

01 Feb '12

Hello all, I have finished making the modifications requested by the Boost.Local(Function) review. The code is now in the sandbox ready to be moved into trunk. Can I get write access to the trunk? 1) Boost.LocalFunction New: This library allows to program functions locally, directly within the scope where they are needed. https://svn.boost.org/svn/boost/sandbox/local_function/libs/local_function/… 2) Boost.ScopeExit Improved APIs (variadic macros, this_, void, and C++11 closures) while keeping full backward compatibility. https://svn.boost.org/svn/boost/sandbox/local_function/libs/scope_exit/doc/… 3) Boost.Utility/IdentityType New: Macro to wrap type expressions within round parenthesis so they can be passed to macros even when they contain commas. https://svn.boost.org/svn/boost/sandbox/local_function/libs/utility/identit… 4) Boost.Functional/OverloadedFunction New: Overload different functions into a single function object. https://svn.boost.org/svn/boost/sandbox/local_function/libs/functional/over… All source files: https://svn.boost.org/svn/boost/sandbox/local_function/ Thanks. --Lorenzo

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[math_constants] Lots of "extra ';'" warnings
by sguazt 31 Jan '12

31 Jan '12

Hello, When compiling with GCC 4.6.2 with flags "-Wall -Wextra -ansi -pedantic", I get the following warnings: boost/math/constants/constants.hpp:211:199: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:212:200: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:213:204: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:214:205: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:215:209: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:216:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:217:205: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:218:208: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:219:201: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:220:206: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:221:207: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:222:211: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:223:197: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:224:202: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:225:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:226:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:227:201: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:228:208: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:229:212: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:230:209: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:231:209: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:232:214: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:233:202: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:234:207: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:235:206: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:236:210: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:237:210: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:238:209: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:239:208: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:240:214: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:241:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:242:201: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:243:209: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:244:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:245:202: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:246:210: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:247:196: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:248:209: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:249:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:250:201: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:251:202: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:252:210: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:253:201: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:254:201: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:255:202: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:256:202: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:257:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:258:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:259:198: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:260:201: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:261:209: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:262:200: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:263:208: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:264:204: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:265:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:266:205: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:267:202: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:268:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:269:203: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:270:217: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:271:212: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:272:212: warning: extra ‘;’ [-pedantic] boost/math/constants/constants.hpp:273:219: warning: extra ‘;’ [-pedantic] Could you fix them? Thank you very much, Best, -- Marco

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[strings][unicode] Proposals for Improved String Interoperability in a Unicode World
by Beman Dawes 31 Jan '12

31 Jan '12

Beman.github.com/string-interoperability/interop_white_paper.html describes Boost components intended to ease string interoperability in general and Unicode string interoperability in particular. These proposals are the Boost version of the TR2 proposals made in N3336, Adapting Standard Library Strings and I/O to a Unicode World. See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3336.html. I'm very interested in hearing comments about either the Boost or the TR2 proposal. Are these useful additions? Is there a better way to achieve the same easy interoperability goals? Where is the best home for the Boost proposals? A separate library? Part of some existing library? Are these proposals orthogonal to the need for deeper Unicode functionality, such as Mathias Gaunard's Unicode components? --Beman

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[c++TR2] N3334, Proposing array_ref<T> and string_ref
by Beman Dawes 31 Jan '12

31 Jan '12

On Sat, Jan 28, 2012 at 8:12 PM, Mathias Gaunard <mathias.gaunard(a)ens-lyon.org> wrote: > On 01/28/2012 05:46 PM, Beman Dawes wrote: >> >> Beman.github.com/string-interoperability/interop_white_paper.html >> describes Boost components intended to ease string interoperability in >> general and Unicode string interoperability in particular. >> >> These proposals are the Boost version of the TR2 proposals made in >> N3336, Adapting Standard Library Strings and I/O to a Unicode World. >> See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3336.html. >> >> I'm very interested in hearing comments about either the Boost or the >> TR2 proposal. Are these useful additions? Is there a better way to >> achieve the same easy interoperability goals? > > > I think you should consider the points being made in N3334. See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3334.html While this proposal isn't from Boost, it impacts interests of Boost developers enough that I think it is worth discussing here as a separate topic. Mathias continues: > While that proposal is in my opinion not good enough, it raises an important > issue that is often present with std::string-based or similar designs. > > A function that takes a std::string, or a boost::filesystem::path for that > matter, necessarily causes the [caller] to copy the data into a heap-allocated > buffer, even if there is no need to. Some std library string implementations avoid the heap allocation for small strings, but still there is an unnecessary copy happening even in those implementations. Your point is well taken and I've often worried about it with boost::filesystem::path. > Use of the range concept would solve that issue, but then that requires > making the function a template. A type-erased range would be possible, but > that has significant performance overhead. > a string_ref or path_ref is maybe the lesser evil. One of my blink reactions is that array_ref<T> and basic_string_ref<charT, traits> are range generators and I was a bit surprised to see the implementation was a pointer and length rather than two pointers. Or better yet, two iterators or an explicit range component. With iterators, a basic_string_ref could do encoding conversions on-the-fly without need of temporary strings. But I have no idea if that is workable or actually is better. What do other Boosters think? --Beman --Beman

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