March 2014 - Boost - lists.preview.boost.org

Getting Started with Boost - GSOC 2014
by Harika Matha 03 Mar '14

03 Mar '14

Hi I am Matha Harika. I have received my bachelor's degree in Electronics and Communication Engineering and currently pursuing Masters in CS from IIIT Hyderabad. I am quite comfortable programming in C++. I have checked the proposed project list of Boost and am very excited to contribute(hopefully in GSOC 2014). I have successfully built the Boost libraries. Could anyone please guide me in getting started with the code? Thank You

1 0

Boost.Convert. Take 2.
by Vladimir Batov 03 Mar '14

03 Mar '14

Another day I came across a topic called "String to T conversions - getting it right this time <http://groups.google.com/a/isocpp.org/group/std-proposals/t/a9905ba8e4f33f3e>" on the "ISO C++ Standard - Future Proposals <https://groups.google.com/a/isocpp.org/forum/#%21forum/std-proposals>" that got me interested/curious. Unfortunately, it seemed more of a discussion rather than a proposed/deployable solution to the string conversion issue. Then, I searched Boost archives to see if there was any development in that string-to-type conversion domain since my unsuccessful proposal about three years ago: From: Edward Diener <eldiener <at> tropicsoft.com> Subject: [Review] Boost.Convert, review manager analysis <http://news.gmane.org/find-root.php?message_id=iq12fm%24k6c%241%40dough.gma…> Newsgroups: gmane.comp.lib.boost.devel <http://news.gmane.org/gmane.comp.lib.boost.devel>, gmane.comp.lib.boost.user <http://news.gmane.org/gmane.comp.lib.boost.user> Date: 2011-05-06 15:01:06 GMT (2 years, 39 weeks, 6 days, 23 hours and 47 minutes ago) Unfortunately I was not able to find anything. Apologies if I missed something major/serious (I was not exactly closely monitoring the list). Is anyone aware of any work done in the area? If not, then I am thinking if we could revisit the issue the original (and failed) Boost.Convert tried to address. I am not sure about others but for me that quite essential and seemingly simple task is still quite important. I was watching the development of the lexical_cast but did not see it going beyond its original frugal design. So, maybe we might have another look at the code that Boost.Convert has become and that I've been using/working on?.. Convert V2... From past experience calling it Boost.Convert seems quite premature. :-) I only put Boost.Convert in the title as a reminder for those who participated in the original review. So, the code is at https://github.com/yet-another-user/boost.xtra. The docs are old (from the original proposal) so, if anyone interested, I'd suggest jumping right to the test/example code in libs/convert/test. Apologies for the inconvenience but for now I'll try to see if I should put any effort updating the docs for possible submission. The main difference from the original proposal is that the complicated blob was split in to two separate components -- Convert API facade and a converter. Here it seems very similar to (same as?) boost::lexical_cast which provides a uniform API facade which in turn deploys additional functionality (op<<, op>>). Similarly, Convert V2 requires a converter to be specified for conversion: boost::cstringstream_based_converter ccnv; // char converter boost::wstringstream_based_converter wcnv; // wchar_t converter Then, int a000 = convert<int>::from(not_int_str, -1, ccnv); int a001 = convert<int>::from(std_str, -1, ccnv); int a002 = convert<int>::from(c_str, -1, ccnv); int a003 = convert<int>::from(wstd_str, -1, wcnv); int a004 = convert<int>::from(wc_str, -1, wcnv); Now all the configuration (formatting, locales, etc.) is separate from the API facade and provided (or not) by the plugged in converter. The only available converter tringstream_based_converter allows something like: std::locale rus_locale (rus_locale_name); std::locale eng_locale (""); // Set locale, case, precision, ccnv(std::setprecision(4))(std::scientific)(std::nouppercase); string double_rus = convert<string>::from(double_v01, ccnv(rus_locale)).value(); string double_eng = convert<string>::from(double_v01, ccnv(eng_locale)).value(); Gosh, it's getting too long... cutting it short. The above is probably sufficient for those who participated in the original review. Those who did not might have a look at the (original and old) docs and the test/example code. V.

9 45

testing potential GSOC students
by David Bellot 02 Mar '14

02 Mar '14

Hi Boost mentors, I'd like to know how you test your potential students to see if they have a sufficient level in C++. It's totally different than doing a C++ interview, because they have plenty of time to answer questions and they can use help from google or any other source. For Boost.uBLAS, I ask them to write a little vector library (vector in the sense of linear algebra) using expression templates. It's the bare minimum they have to know. I ask different features to each student. They we talk about their code and I ask them to modify it to introduce new features for example. And you ? Best regards, David

3 2

Re: [boost] [Re] [Re] JSON Parsing Library for GSoC 14
by Ganesh Prasad 01 Mar '14

01 Mar '14

Yeah, the parser generator can be easily implemented using Boost.spirit.qi . So, implementing that would not be much for GSoC. But I have another (a bit complex) idea in this field. Rather than writing a tool to generate tag based DSEL parsers, I can work on one abstraction level up... A tool to generate formal grammars themselves. Why not a library that would take Two level Grammar (Ex : Van Wijngaarden Grammar ) and build parser for the resulting CFG ... It's established that two level grammars are more powerful than single level CFGs and that two level grammars are Turing Complete themselves. So, if we can just implement them in a proper way (maybe I am day dreaming), we might end up with something like the discovery of metaprogramming. I daresay, this dream of mine is feasible, but right now, vague. Provided with some intellectual help, I may come up with a design for such a library in a matter of days. Best wishes Ganesh Prasad

3 2

[Re] [Re] JSON Parsing Library for GSoC 14
by Ganesh Prasad 01 Mar '14

01 Mar '14

So basically, the idea of generalization is like this : -- A compile time library to work just like parser building tools (ex: yacc). -- The library is to generate small sized fast and embed-able parsers for tag based/markup languages like XML, TeX etc. -- The parsing mechanism of the library is to be simpler than that of mainstream DCFG parsing tools, yet powerful enough to generate parsers for all kinds of tag based languages. -- An event handling mechanism. When an tag/end-of-tag is encountered an event is generated and this event is to be handled. The library is to provide features for this. -- Mechanism to bind functions/function objects to events.

2 1

[assert] Assert library? - Was: [regression] Where's boost/assert.hpp ??
by Klaim - Joël Lamotte 01 Mar '14

01 Mar '14

On Sat, Feb 22, 2014 at 9:39 PM, Andrey Semashev <andrey.semashev(a)gmail.com>wrote: > It's been moved to a new Boost.Assert library (libs/assert submodule). Is there a discussion or documentation about what is this new library exactly? Is it just to isolate the assert.hpp header or are there other plans? (I'm secretly hoping that someone would propose an implementation of n3877[1] to boost, as I don't have the time to do it myself) [1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3877.pdf

5 17