- Boost-users - lists.boost.org

RE: [Boost-users] Re: copy_if
by Ben Hutchings 15 Sep '03

15 Sep '03

Witz <witz(a)nildram.co.uk> wrote: > You can find an implementation of copy_if in Boost Wiki here: > > http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl > ?STLAlgorithmExtensions > > An extension that i find useful is the following: > > template<class II, class OI, class PRED> > std::pair<II,OI> copy_if(II ibegin, II iend, OI obegin, OI oend, > PRED p) > { > for(; ibegin != iend; ++ibegin) > { > if(p(*ibegin)) > { > *obegin = *ibegin; > if(++obegin == oend) > break; > } > } > return std::make_pair(ibegin, obegin); > } > > Here we have a finite sized sink. Items are copied from the source if > they satisfy the condition and if there is room left in the sink. The > positions reached are returned on termination of the algorithm. This should check whether obegin == end before copying, in case obegin == oend initially. I don't know whether it should stop as soon as it finds obegin == oend or wait until it knows there's another item to be copied. The former behaviour saves a little time in the case that no more items are wanted once the output buffer is full. The latter behaviour avoids the occasional need for another pass that copies nothing, if copy_if is called repeatedly to fill an output buffer which is then flushed. Ben.

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BGL: finding all minimum cut sets
by Trevon Fuller 14 Sep '03

14 Sep '03

Does anyone know how to find all of the minimum size cut sets of a graph (if more than 1 exists) using the BOOST graph library? The example in the BGL book just finds 1 minimum cut set (p. 106ff.).

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Cygwin: Building a static libboost_thread
by Reed Hedges 14 Sep '03

14 Sep '03

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello, I have tried every combination of BUILD parameters but I can't seem to get a static libboost_thread.a on gcc/Cygwin (in "no cygwin" mode: TOOLS=gcc-nocygwin). Is it possible? I am using 1.30.2, IIRC. (If on the other hand someone knows how to get DevC++ (with msys gcc) to link against the shared library that would be helpful too) thanks reed - -- Reed Hedges reed(a)zerohour.net http://zerohour.net/~reed -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (Darwin) iD8DBQE/ZHFRFK83gN8ItOQRArZRAJ9M6ohiYEoPqIjXurvdJrx07YJ4TACfcHRg 5d3XguoTJNDWGgSId/zKcEY= =t/LR -----END PGP SIGNATURE-----

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Test
by Victor A. Wagner, Jr. 13 Sep '03

13 Sep '03

I haven't received anything in over a week, this is just a test of the address, please ignore. Victor A. Wagner Jr. http://rudbek.com The five most dangerous words in the English language: "There oughta be a law"

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Re: copy_if
by Witz 13 Sep '03

13 Sep '03

You can find an implementation of copy_if in Boost Wiki here: http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?STLAlgorithm… An extension that i find useful is the following: template<class II, class OI, class PRED> std::pair<II,OI> copy_if(II ibegin, II iend, OI obegin, OI oend, PRED p) { for(; ibegin != iend; ++ibegin) { if(p(*ibegin)) { *obegin = *ibegin; if(++obegin == oend) break; } } return std::make_pair(ibegin, obegin); } Here we have a finite sized sink. Items are copied from the source if they satisfy the condition and if there is room left in the sink. The positions reached are returned on termination of the algorithm. Witz

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Documentation links don't
by ygor＠comcast.net 13 Sep '03

13 Sep '03

The links for PDF/HTML documentation do not work. Thanks.

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RE: [Boost-users] Re: tupl::get bag
by Ben Hutchings 12 Sep '03

12 Sep '03

nagual <nagual(a)promsoft.ru> wrote: <snip> > I correct line 12 & 13: > > tie(i1, i2, i3, c1, c2, c3).template get<num>() = t; > cout<<tie(i1, i2, i3, c1, c2, c3).template get<num>()<<endl; > > g++ (GCC) v 3.2.2 now compile ok. > > But cl (MSVC) v 13.00.9466 output not change. ;-c The problem there must be something else. VC++ 7.1 accepts the code with or without "template".

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copy_if
by Mr Zenaan Harkness 12 Sep '03

12 Sep '03

Does boost have an implementation of copy_if that I can't find yet? Just wondering, because it is an algorithm that, according to both stroustrup and o'rielly, should have been part of the standard but was essentially accidentally forgotten. Surely this (and possibly other necessary additions) would be part of an boost algorithm library, even if only one or two functions... I need copy_if, both these books I have say it's one of "the first generic algorithm that most programmers will probably write", so where is it? ??? (Yes, I can type it in, but boost is supposed to fill in the blanks, yes?) tia zen

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boost::char_separator enhancement (or, how do I do it myself)
by Mr Zenaan Harkness 12 Sep '03

12 Sep '03

I'm teaching myself C++, and want to tokenize my stream, using boost::tokenizer. I want to be able to optionally tokenize with or without including the delimiter character - this is supported. However: the delimiter character, if included, becomes its own token. I want an option to have the delimiter character be part of the previous token (which is what makes sense for the processing I am doing on my files). ??? ta zen

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Boost's pool implementation
by Thomas Harning 11 Sep '03

11 Sep '03

First off, I think the Boost pool is a great tool and for me has been one of the most useful of Boost's libraries. I have run into a problem however, due to the pool's usage of "malloc" and "free" as the names of functions. The problem is that I want to debug memory usage in my program and catch memory leaks, but using the leak detection in Visual Studio 7.1 for the CRT creates a macro for malloc and free, which conflicts with the pool's malloc and free and makes a general mess. Is there any better memory debug library/tools out there that are free and can get the line/file that the memory allocation occurred and the size perhaps and possibly a portion of the contained data as a character string? Perhaps I could write up a patch to rename the malloc and free from the boost pool [though I see that would be quite a pain to the existing users of boost's pool since code would have to be rewritten with whatever function is added]. Thanks. Thomas Harning Jr.

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