November 2011 - Boost - lists.preview.boost.org

[Boost.Local] Review
by Hartmut Kaiser 25 Nov '11

25 Nov '11

This is not a full review, mainly because I have not had the time to devote more than a quick glance over the documentation (which is a good read, btw). Upfront my vote: no, please do not include this library into Boost. My reasons are: a) Boost is a library which has quite some visibility not only for library writers but also for application developers. IMHO, Boost not only has the task of finding new ways for using C++, but it plays the role of evangelizing good programming style, great API design, and thoughtful functionality. Using macros as the sole API of a library to be mainly used by application writers (not library authors) is not a good idea because of all those well know problems related to macros: difficult to debug, error messages are even more difficult to interpret than those generated by TMP, macros are type agnostic and have absolutely no knowledge of C++, etc. b) The proposed library does not add any functionality which couldn't be _easily_ replaced by using existing C++ language features or libraries. This is especially true if we talk about C++11 (which we should, IHMO). c) A very personal reason: code written based on the proposed library for me tends to be an unreadable mess. I have problems to remember, what arguments to the macros means what, when to use additional parenthesis and when not, etc. This is especially true when it comes to using 'default' and 'bind' in the argument list. This just does not 'look right' to me. Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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Re: [boost] [local] Any "active Boost library author" in favor of Boost.Local
by Brian Wood 25 Nov '11

25 Nov '11

Lorenzo Caminiti: > Hello all, > > I will be honest: The fact that some of the people arguing for not > including Boost.Local are "active Boost library authors" (Thomas, > Joel, and Hartmut) seems to make their opinion weight more than the > opinion of others that have also submitted a review for the library. > > Two questions: > 1) Should reviews from "active Boost library authors" carry more > weight? (This is /not/ a rhetoric question.) > 2) Is there any "active Boost library author" out there that is in > favor of including Boost.Local? (If so, please say so by replying to > this thread.) I'm in favor of accepting it. Not because I plan to use it, but think Boost could use the help and you have been learning the ropes. Regardless of the outcome of the review, I like the tenacity you've shown. I'm not a Boost library author. -- Brian Wood Ebenezer Enterprises http://webEbenezer.net <http://webebenezer.net/>

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Error in the getting started guide?
by Philip Bennefall 24 Nov '11

24 Nov '11

I was just looking at the getting started guide on Windows for version 1.48.0 and saw this paragraph: The easiest way to get a copy of Boost is to use an installer. The Boost website version of this Getting Started guide will have undated information on installers as they become available, ..." I'm guessing it should be "updated"? It might confuse new users slightly so I thought I'd mention it. If the list is not the right place for this note, then I apologize. Kind regards, Philip Bennefall

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[lexical_cast] Error casting void* to std::string
by GMan 24 Nov '11

24 Nov '11

I did a search on the mailing list and found nothing, but apologies if I missed it. This bug seems to be new to 1.48. Compiling the following code in MSVC2010: #include <boost/lexical_cast.hpp> #include <string> int main() { void* ptr = 0; boost::lexical_cast<std::string>(ptr); } Results in an error, pointing to line 1738 in boost\lexical_cast.hpp, stating: 'removed_ptr_t': illegal sizeof operand. ('removed_ptr_t' is, however, defined a few lines above.) I see nothing wrong with the code from a C++ point-of-view, so I'm guessing this is another MSVC bug. Is this known? I don't see an immediate permanent workaround. A client-side workaround exists by introducing this small class: struct print_ptr { explicit print_ptr(void* ptr) : mPtr(ptr) {} friend std::ostream& operator<<(std::ostream& sink, print_ptr printPtr) { return sink << printPtr.mPtr; } private: void* mPtr; }; And using: boost::lexical_cast<std::string>(print_ptr(ptr)); -- GMan, Nick Gorski

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Re: [boost] What is boost:
by Brian Wood 24 Nov '11

24 Nov '11

From: Gregory Crosswhite > Perhaps, but could you give us some examples of what you mean to provide a better sense of what you are thinking? Thanks! :-) If a library hasn't had a maintainer for a certain period then it gets removed. If I'm using a library that is close to being removed I'd either have to do something to help maintain it or decide to use another library. I'm OK with it becoming easier to add libraries if it also becomes easier to remove them. -- Brian Wood Ebenezer Enterprises http://webEbenezer.net <http://webebenezer.net/>

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Policy when duplicate code detected
by Ioannis Papadopoulos 24 Nov '11

24 Nov '11

Hi, I was wondering what is the policy when someone finds code that is clearly duplicated or implements the same thing with just different interface? What is the best way to report it? Thanks

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Re: [boost] What is boost:
by Brian Wood 24 Nov '11

24 Nov '11

Lorenzo Caminiti: >On Wed, Nov 23, 2011 at 2:09 PM, Robert Ramey <ramey(a)rrsd.com> wrote: >> >> So I'm more of the view that we let stuff into boost as long at it meets >> quality standards. ?Then let users decide. > > +1 I guess, but is there any way to remove libraries from Boost? I think it almost needs pruning more than it needs more libs. -- Brian Wood Ebenezer Enterprises http://webEbenezer.net

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Re: [boost] [Boost.Local] Review
by Brent Spillner 24 Nov '11

24 Nov '11

On 23 Nov 2011 10:24:53 Leo Goodstadt wrote: >For "acknowledgment" / "acknowledgement": both spellings started out in the >16th c. but the first form historically was found more in the US. Citations >from the 19th and 20th c show that both variants are found on both sides >of the Atlantic (e.g. the short form in the UK in Dickens, Bronte, Macaulay) >though the long form seems to predominate in the 20c only in U.K. >newspapers. I too appreciate the clarification--- guess I didn't understand this quite as well as I thought. In the US, "acknowledgement" does seem to correlate frequently with a casual attitude toward spelling, but it looks like I need to broaden my horizons a bit.

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Re: [boost] [local] Review (and resignation from review assistant)
by Andrzej Krzemienski 23 Nov '11

23 Nov '11

> > Ok, I am not sure if there are no better ways to write it in each variant, > > and I may be biased. I also didn't try to compile the examples. But it > > should give the potential users an overview of options they have. > > Yep. This highlights the verbosity well: > for_each( vec.begin(), vec.end(), if_(empty(_1)) [_1 = "n/a"] ); > vs: > BOOST_CLOSURE_PARAMS( std::string & n ) { > if( n.empty() ) n = "n/a"; > }BOOST_CLOSURE_NAME(replace_empties); > for_each( vec.begin(), vec.end(), replace_empties ); Honestly, my goal was to show an example where Phoenix has limitations and Local could be considered an attractive alternative. Obviously my example failed to do that. I wanted to see how you can call member functions. I can see Phoenix has nice support for container-like operations. But how about changing the rules a bit, and calling an arbitrary member function? for_each( vec.begin(), vec.end(), if_(bind(&SuperLib::SuperString::IsVulgar, arg1)) [arg1 = "unknown" ] ); vs. BOOST_CLOSURE_PARAMS( SuperLib::SuperString & n ) { if( n.isVulgar() ) n = "unknown"; }BOOST_CLOSURE_NAME(replace_vulgar); for_each( vec.begin(), vec.end(), replace_vulgar ); I realize that one can tweak examples to show whatever one wants. But member access does not appear too unusual. This really happened to me that I used a very complicated bind statement where I had to bind some variables and leave some free, pass some by reference, some by value. I thought "it was the right way because this is Boost way", until I realized no-one else in the team knows what that is suppose to mean. Regards, &rzej

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[parameter] increase BOOST_PARAMETER_MAX_ARITY
by Tim Blechmann 23 Nov '11

23 Nov '11

hi, i've been using boost.parameter extensively with boost.heap and now came to a point, that i need to raise BOOST_PARAMETER_MAX_ARITY to at least 7 in order to be able to compile it. i am planning to merge boost.heap into trunk in the next few days, so i wonder, would it be reasonable to increase the default of this value to e.g. 8 (patch attached)? currently, boost.heap defines BOOST_PARAMETER_MAX_ARITY before including boost/parameter.hpp, but this will break, if boost/parameter.hpp is included before the boost.heap headers. it would be great, if the default would be high enough to compile all boost libraries, or could this cause any issues? thanks, tim

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