April 2008 - Boost-users - lists.preview.boost.org

boost file system library question
by Dan Sherman 08 Apr '08

08 Apr '08

All, I have been having some bad experiences with copying directories. I am currently using system(xcopy /e source destination). Sometimes it works, and sometimes it doesn't which landed me here. I am trying to get a simple test working to emulate this with the boost libs. I have only been coding in C++ for two weeks. So I accept all suggestions and critisim. Also if anyone had any insight into the security implications of the xcopy system call vs. the boost filesystem lib that would be helpful. Thanks in advance, Dj

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[BGL] Hypergraphs
by Ioannis Nousias 08 Apr '08

08 Apr '08

Hi everyone. Are hypergraphs representable in BGL? I'm interested in a hypergraph partitioning algorithm using boost. regards, Ioannis -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.

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boost build for Windows
by rishi keisham 08 Apr '08

08 Apr '08

Hi all, I am trying to build boost for Windows... , I am currently using Visual studio 2005 Express edition (vc8). Here are the steps that I follow. 1) download boost_1_33_1 2) run build.bat from c:\boost_1_33_1\tools\build\jam_src. 3) copy bjam.exe to c:\windows . 4) set BOOST_BUILD_PATH=c:\boost_1_33_1\tools\build\v2 5) Modify user_config.jam accordingly to using msvc : 8.0 ; 6) set BOOST_ROOT = c:\boost_1_33_1 7) run bjam... But I got C:\boost_1_33_1>bjam ****************************************************** Building Boost.Iostreams with bzip2 support disabled. To enable bzip2, consult the Boost.Iostreams documentation ****************************************************** ****************************************************** Building Boost.Iostreams with zlib and gzip support disabled. To enable zlib and gzip, consult the Boost.Iostreams documentation ****************************************************** --------------------------------------------------------------------- *** If you don't need Boost.Python, you can ignore this section *** *** pass --without-python to suppress this message in the future *** skipping Boost.Python library build due to missing or incorrect configuration couldn't find Python.h in "c:/Python24/include" You can configure the location of your python installation by setting: PYTHON_VERSION - The 2-part python Major.Minor version number (e.g. "2.2", NOT "2.2.1") - currently "2.4" PYTHON_ROOT - automatically configured from PYTHON_VERSION if not otherwise set ; currently "c:/Python24" The following are automatically configured from PYTHON_ROOT if not otherwise set: PYTHON_LIB_PATH - path to Python library object; currently "c:/Python24/libs" --------------------------------------------------------------------- Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (and if you don't know what ICU is then you probably don't need it). ...found 9007 targets... ...updating 1238 targets... vc-C++ bin\boost\libs\date_time\build\boost_date_time.dll\vc-7_1\debug\threading -multi\greg_month.obj The system cannot find the path specified. The system cannot find the path specified. CALL "C:\Program Files\Microsoft Visual Studio .NET 2003\VC7\bin\VCVARS32.BA T" >nul "C:\Program Files\Microsoft Visual Studio .NET 2003\VC7\bin\cl" /Zm800 -nol ogo /EHsc -c -DBOOST_ALL_DYN_LINK=1 -DUSE_DATE_TIME_PRE_1_33_FACET_IO /Z7 /Od /Ob0 /EHsc /GR /MDd /Op /wd4675 /Zc:forScope /Zc:wchar_t -I"bin\boost\libs\dat e_time\build" -I"C:\boost_1_33_1" -Fo"bin\boost\libs\date_time\build\boost_d ate_time.dll\vc-7_1\debug\threading-multi\greg_month.obj" -Tp"C:\boost_1_33_1\l ibs\date_time\build\../src/gregorian/greg_month.cpp" ...failed vc-C++ bin\boost\libs\date_time\build\boost_date_time.dll\vc-7_1\debug \threading-multi\greg_month.obj... vc-C++ bin\boost\libs\date_time\build\boost_date_time.dll\vc-7_1\debug\threading -multi\greg_weekday.obj The system cannot find the path specified. The system cannot find the path specified. CALL "C:\Program Files\Microsoft Visual Studio .NET 2003\VC7\bin\VCVARS32.BA T" >nul "C:\Program Files\Microsoft Visual Studio .NET 2003\VC7\bin\cl" /Zm800 -nol ogo /EHsc -c -DBOOST_ALL_DYN_LINK=1 -DUSE_DATE_TIME_PRE_1_33_FACET_IO /Z7 /Od /Ob0 /EHsc /GR /MDd /Op /wd4675 /Zc:forScope /Zc:wchar_t -I"bin\boost\libs\dat e_time\build" -I"C:\boost_1_33_1" -Fo"bin\boost\libs\date_time\build\boost_d ate_time.dll\vc-7_1\debug\threading-multi\greg_weekday.obj" -Tp"C:\boost_1_33_1 \libs\date_time\build\../src/gregorian/greg_weekday.cpp" ...failed vc-C++ bin\boost\libs\date_time\build\boost_date_time.dll\vc-7_1\debug \threading-multi\greg_weekday.obj... vc-C++ bin\boost\libs\date_time\build\boost_date_time.dll\vc-7_1\debug\threading -multi\date_generators.obj its very stranger that it always take the path for vc7.1. Can Anyone tell what is the other way to build boost for Windows. I have previously tried for Monta Vista Linux too, sorry its fails to compile. Thanks, Rishi --------------------------------- Bollywood, fun, friendship, sports and more. You name it, we have it.

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Cannot compile boost 1.35 under ubuntu linux
by Germán Diago 08 Apr '08

08 Apr '08

Hello. I tried to configure boost in order to be able to install it. But the configure archive seems to be broken. bash: ./configure: /bin/sh^M: bad interpreter: No such file or directory The output shows a ^M symbol after /bin/sh. It seems to be an encoding problem. So I tried to delete that line and invoke the script with the shell explicitly: /bin/bash ./configure --prefix=/usr But I get this error: : command not found: : command not found: : command not found2: : command not found7: '/configure: line 29: syntax error near unexpected token `do '/configure: line 29: `do Any solution, please? Thanks in advance.

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boost.lambda for_each and boost.array
by Olaf Peter 08 Apr '08

08 Apr '08

Hi, these snipped doesn't compile, but why? ---8<--- #include <iostream> #include <boost/array.hpp> #include <boost/lambda/lambda.hpp> int main() { using namespace ::boost::lambda; boost::array<double, 10> values; for_each( values.begin(), values.end(), _1 = 2.0 ); for_each( values.begin(), values.end(), std::cout << _1 << '\n'); } --->8--- error: 'for_each' was not declared in this scope using std::list compiles and works. Did I miss something? Thanks, Olaf

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drop-dead simple example of custom Boost.Range?
by John 08 Apr '08

08 Apr '08

I'm trying to get boost range and iterator to work. I've got so many questions, I don't know where to start. So, rather than post a specific compiler error, let's go back to square one. How about a concrete example of fitting a UDT with Boost.Range? Say I have a class with a non-trivial iterator type (not a pointer!) I'd like to modify the class so that Boost.Range is happy. At some point, I feel as though I just end up arbitrarily copying snippets from the docs in the hope that it will all work. Is there something I'm not "getting" about boost.range? The code below is an attempt to create a working skeleton example. Obviously, the author lacks whatever magic spell book is required to put it all together -- "it" being a user-defined type, plus Boost.Range. Seems like something as simple as a modeling a range should be easier than breathing, so I'm hoping it actually is, and that I'm just missing something totally obvious to everyone else. So, is the following skeleton correct? Where does it go awry? Can we perhaps clean it up, make it perfect, and introduce it (or something like it) to the Boost.Range docs? // An arbitrary container-esque class. class Foo { public: class iterator : public boost::iterator_facade < iterator, Foo::value_type, boost::random_access_traversal_tag, Foo::value_type, ptrdiff_t // Difference type? > { public: iterator (); // no-arg ctor required by boost? private: iterator (internal_stuff); // "real" ctor friend class boost::iterator_core_access; friend class Foo; // Required by iterator_facade? void increment(); void decrement(); void advance (ptrdiff_t); ptrdiff_t distance_to (const iterator&) const; bool equal (const iterator&) const; Foo::value_type dereference() const; }; // Required by Boost.Range? iterator end() const; iterator begin() const; // Blatant shot in the dark here... typedef boost::sub_range< Foo > range_type; // Walking blindfolded, with earplugs, and wearing mittens. range_type produce_a_range_somehow () const { iterator a = this->begin(); iterator b = this->begin(); some_algorithm_here (a, b, this->end()); return range_type (a, b); } // Now it gets bad. void use_a_range_somehow (range_type r) { // Starting to feel as though Kansas is far, far away. // Wondering where the past 4 hours went. // Wondering why I don't just use a custom std::pair-like range. // Am I cursed or blessed by the commitment to Boost? } };

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[boost][lexical_cast] simple example doesn't work with vector<T>
by Andy Stevenson 08 Apr '08

08 Apr '08

Hi, Sorry trivial questions I'm sure. Why doesn't the lexical_cast work below? I think it meets the concept description. * Source is OutputStreamable, meaning that an operator<< is defined that takes a std::ostream or std::wostream object on the left hand side and an instance of the argument type on the right. * Target is InputStreamable, meaning that an operator>> is defined that takes a std::istream or std::wistream object on the left hand side and an instance of the result type on the right. * Target is CopyConstructible [20.1.3]. * Target is DefaultConstructible, meaning that it is possible to default-initialize an object of that type [8.5, 20.1.4]. >>>>> play.cpp >>>> #include <vector> #include <iostream> #include <algorithm> #include <boost/bind.hpp> #include <boost/lexical_cast.hpp> #include <boost/filesystem.hpp> #include <sstream> using namespace std; using namespace boost; using namespace boost::filesystem; template<class T> ostream& operator<< (ostream& os, const vector<T>& v) { copy(v.begin(), v.end(), ostream_iterator<T>(os, ";")); return os; } template<class T> string v2s(const vector<T>& v) { stringstream ss; copy(v.begin(), v.end(), ostream_iterator<T>(ss, ";")); return ss.str(); } int main(int argc, char* argv[]) { vector<string> v; v.push_back("hello"); v.push_back("world"); cout << v << endl; cout << v2s(v) << endl; cout << lexical_cast<string>(v) << endl; // XXX doesn't compile...XXX return 0; } Any help greatly appreciated. Andy

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installing the math toolkit
by e r 08 Apr '08

08 Apr '08

hi all, please, I'm looking for some directions for installing the math toolkit: 1) downloaded math toolkit headers: http://www.boost-consulting.com/vault/index.php?action=downloadfile&filenam… 2) As per instructions in http://www.boost-consulting.com/vault/index.php?action=downloadfile&filenam… i.e. Extract to a directory separate from your boost tree, then set the environment variable BOOST_ROOT to point to a copy of boost-1.34 (release branch cvs) or to 1.35 (cvs HEAD). I now have in my directory structure: /usr/local/boost_1_34_1 /usr/local/boost/math and in ./bashrc I added export BOOST_ROOT="/usr/local/boost_1_34_1" 3) I have added "/usr/local/boost/math" in the include path of the compiler (I use eclipse cdt) 4) in main.cpp: #include <boost/math/fpclassify.hpp>//warning: boost/math/fpclassify.hpp: No such file or directory int main() { using namespace boost::math; /*...*/ return 0; }

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[Proto] Review result
by Hartmut Kaiser 07 Apr '08

07 Apr '08

Hi all, initially I was hoping to find some time over the last weekend to go through the reviews in great detail to put together a proper review report. Well, as things happen, I was not able to find the time :-( To avoid further delays, here is the short version of the review result: Proto got 16 reviews (That's well above average! Thanks to all for participating), out of which 15 have been positive. The one 'No' essentially stated that the library, even if doubtless very useful, shouldn't be accepted yet, mainly because there has to be done more work in the area of formalizing the problem domain. In my opinion this is an overwhelming result and I'm whole heartily agreeing with the majority of the voters. Proto is accepted as a Boost library. The discussions have been very detailed and there have been raised a lot of (mostly minor) issues, but Eric is aware of the problems and is working on solving them. I'll try to put together a summary as soon as possible. Regards Hartmut Review Manager

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Network Attached Memory
by James Board 07 Apr '08

07 Apr '08

With Java, there exists something called Network Attached Memory (a Terracotta product). It basically increases the effective RAM of any single machine by allowing it to use RAM on another machine. But that's Java. Is there an equivalent thing for C++? Specifically, I have a cluster of nodes with a moderate amount of memory (8 gbytes each) and a very fast network (10 microsecond small message latency and 750 mbytes/second large message bandwidth). I have a C++ application that needs tens of gbytes of RAM. Is there some kind of product, or library, that would allow the C++ application to seemlessly use the memory on other nodes as if it had a much larger RAM? James --------------------------------- You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost.

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