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

Equality comparison of boost::function<>
by Zachary Turner 02 Sep '09

02 Sep '09

Is this possible? I always get ambiguities when I try it. Here's some sample code: class foo { public: typedef enum { lost, reset } device_event; typedef boost::function<void (window&, device_event)> device_listener; void add_listener(const device_listener& listener) { std::list<device_listener>::const_iterator iter = std::find(listeners_.begin(), listeners_.end(), listener); if (iter == listeners_.end()) listeners_.push_back(listener); } private: std::list<device_listener> listeners_; }; The above is slightly simplified from my actual code, but when I do this I get the following: I'm using Visual C++ 9.0 SP1 1>f:\dev\testing\window.h(42) : error C2666: 'operator ==' : 4 overloads have similar conversions 1> q:\include\boost\1.39.0\boost\function\function_template.hpp(995): could be 'void boost::operator ==<R,T0,T1>(const boost::function2<R,T0,T1> &,const boost::function2<R,T0,T1> &)' [found using argument-dependent lookup] 1> with 1> [ 1> R=void, 1> T0=zg::window &, 1> T1=zg::window::device_event 1> ] 1> q:\include\boost\1.39.0\boost\function\function_base.hpp(791): or 'bool boost::operator ==<zg::window::device_listener>(Functor,const boost::function_base &)' [found using argument-dependent lookup] 1> with 1> [ 1> Functor=zg::window::device_listener 1> ] 1> q:\include\boost\1.39.0\boost\function\function_base.hpp(782): or 'bool boost::operator ==<zg::window::device_listener>(const boost::function_base &,Functor)' [found using argument-dependent lookup] 1> with 1> [ 1> Functor=zg::window::device_listener 1> ] 1> or 'built-in C++ operator==(void (__thiscall boost::function2<R,T0,T1>::dummy::* )(void), void (__thiscall boost::function2<R,T0,T1>::dummy::* )(void))' 1> with 1> [ 1> R=void, 1> T0=zg::window &, 1> T1=zg::window::device_event 1> ] 1> while trying to match the argument list '(const zg::window::device_listener, const zg::window::device_listener)' 1

7 13

[BGL] reducing memory requirements for adjacency list
by Soeren Meyer-Eppler 02 Sep '09

02 Sep '09

Hi, I'm using adjacency_list< vecS, vecS, bidirectionalS ... > extensively. I have so many graphs loaded at once that memory becomes an issue. I'm doing static program analysis and store the callgraph and flowgraphs of the disassembled binary in boost graphs. Thus I can have several ten thausand functions==flowgraphs and one gigantic callgraph. I'd really like to reduce memory usage for my graphs while still using the BGL. Since my graphs are static after loading and edge and vertex counts are known beforehand I see huge potential for optimization. For example, I'd like to allocate a single buffer for all vertices/edges of a single graph and let the graph just store indices into that buffer. more questions: 1) what's the memory overhead of using vertex and edge properties? I have quite a few of them. 2) is it possible to convince the BGL to use the shrink to fit idiom? As I understand it the adjacency lists use push_back to add edges. Is it possible to reduce memory usage by swapping the resulting vector with a copy of itself? Maybe by copying the whole graph? 3) Is it possible to use boost pool allocators with the BGL? As far as I can tell the BGL currently performs lots of small allocations - I'd really like to avoid that for space and runtime efficiency reasons. Did anyone already build a BGL version optimized for memory usage? Should I try using the existing graph structures and augment it with custom allocators or somesuch or is it more fruitful to write my own implementation and try to stay interface compatible with the BGL so I may continue to use it's algorithms? best regards, Sören

4 8

Template mailing list / forum
by Ryan McConnehey 02 Sep '09

02 Sep '09

What is a good template forum or mailing list so that I don't clutter the boost mailing list with non boost questions? Ryan

2 2

how to know which libraries to link?
by pedro chaparro 02 Sep '09

02 Sep '09

HI, im newbie with boost, i have a doubt about how to know which libraries u have to link when u compile a cpp file, in the example below for example which would be the libraries to link? i do for example c++ -I boostdirectory myfile.cpp -o myfile [ and here? ]. Im working with ubuntu, and boost 4.0 thanks // // timer.cpp // ~~~~~~~~~ // // Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #include <iostream> #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> int main() { boost::asio::io_service io; boost::asio::deadline_timer t(io, boost::posix_time::seconds(5)); t.wait(); std::cout << "Hello, world!\n"; return 0; } -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

3 2

[Interprocess] assertion while destroying inexistent named instance
by Rui Pedro Fernandes 02 Sep '09

02 Sep '09

Hi, During my tests I found that if I change the managed shared memory index from the default iset_index to map_index the test fails when a process tries to destroy an already inexistent named instance, using its name. With map_index, an assertion fails when the object is found not to be present. Shouldn't it behave like in the case of iset_index ? Thank you. Rui

2 1

Re: [Boost-users] Boost and autocompletion
by dhruva 02 Sep '09

02 Sep '09

Hello, > On Tue, Sep 1, 2009 at 11:24 AM, Germ?n Diagowrote: > > try eclipse with eclipse cdt plugin. In www.eclipse.org you can find a > > bundle of "eclipse for c/c++ developers". > > That's the one you need. > > Yea, that is the best I have seen so far, but nothing gets anywhere > close to the quality of Visual Assist + MSVC sadly, that is my only > main tie to still programming on Windows, the IDE is just so much > better. Might see if it works in wine... Slightly off topic, GNU Global is pretty good in creating the good cross reference. I use it in my project with full boost being indexed. Emacs + Global is my development environment that works on both windoze and gnu/linux. I like the references feature of global which lists all potential locations where the symbol is referred (using pattern match only, same named functions appear even if it is totally unrelated to the symbol you are trying to explore) -dhruva Love Cricket? Check out live scores, photos, video highlights and more. Click here http://cricket.yahoo.com

2 1

Re: [Boost-users] [Spirit] Creating a vector of structs
by Lindley M French 02 Sep '09

02 Sep '09

> On Tue, Sep 1, 2009 at 4:38 PM, Lindley M French<lfrench1(a)gmu.edu> > wrote:> I'm playing around with Spirit for a particular parsing > task. I could do this manually, but I figured this was a good > chance to learn what Spirit had to offer. > > > > The trouble is this. While Spirit offers ready-made semantic > actions for parsing primitives, it doesn't seem to offer anything > terribly useful for compound statements. As far as I can tell, you > can define your own semantic actions but they simply take in the > matched string as an argument----there's no way to get at the > values parsed on that level. > > > > For example, let's say I have a type > > struct Person > > { > > ? string name; > > ? double height; > > ? int age; > > ? Person(string n, double h, int a) > > ? : name(n), height(h), age(a) > > }; > > > > And I have a document containing > > > > 5.5 15 Henry > > 4.6 32 Jane > > 6.1 21 Bob > > > > I could parse this using > > > > rule<> personrule = strict_real_p >> int_p >> ~eol_p; > > parse(str, *(personrule[WhatGoesHere] >> eol_p) >> end_p); > > > > But how can I build a vector<Person> out of this? I can write my > own functor to do the push_back, but I need to get at the parsed > values of name, age, and height for each personrule somehow. > > > > I suppose I *could* just run another parse() on the input the > semantic action for that specific person....but that really seems > like it shouldn't be necessary. > > You are using Spirit.Classic, you should use Spirit.QI (Boost trunk, > docs are at: > http://svn.boost.org/svn/boost/trunk/libs/spirit/doc/html/index.html) then you can do it easy, like so: > > BOOST_FUSION_ADAPT_STRUCT(Person > (double,height) > (int,age) > (string,name) > ) > > rule<YourIteratorType> personrule; > personrule %= double_ >> int_ >> raw[lexeme[*(char_-eol)]]; > std::vector<Person> theVec; > parse(str.begin(),str.end(), *personrule, theVec); > > This is also better to ask on the spirit mailing list. :) Unfortunately for the moment I'm stuck with Boost 1.35, which I don't believe has Spirit 2. I'll try asking on the Spirit list.

2 1

[Spirit] Creating a vector of structs
by Lindley M French 01 Sep '09

01 Sep '09

I'm playing around with Spirit for a particular parsing task. I could do this manually, but I figured this was a good chance to learn what Spirit had to offer. The trouble is this. While Spirit offers ready-made semantic actions for parsing primitives, it doesn't seem to offer anything terribly useful for compound statements. As far as I can tell, you can define your own semantic actions but they simply take in the matched string as an argument----there's no way to get at the values parsed on that level. For example, let's say I have a type struct Person { string name; double height; int age; Person(string n, double h, int a) : name(n), height(h), age(a) }; And I have a document containing 5.5 15 Henry 4.6 32 Jane 6.1 21 Bob I could parse this using rule<> personrule = strict_real_p >> int_p >> ~eol_p; parse(str, *(personrule[WhatGoesHere] >> eol_p) >> end_p); But how can I build a vector<Person> out of this? I can write my own functor to do the push_back, but I need to get at the parsed values of name, age, and height for each personrule somehow. I suppose I *could* just run another parse() on the input the semantic action for that specific person....but that really seems like it shouldn't be necessary.

2 1

Boost and autocompletion
by Hassan Syed 01 Sep '09

01 Sep '09

Hello All, I've been trying to get autocompletion to work under Unix. I do not mind which editor I use really. I was hoping to get the quality of visual studio code completion. I have tried VIM/Ctags/Omnicompletion, Netbeans and Eclipse. The first option does not work well since ctags has a problem indexing boost, the smallest index I could build is 56 mb (after excluding the vector*.hpp files). Netbeans works well however it is dog slow. Eclipse doesn't work at all (perhaps I've done something wrong). Is there a combination for a posix system that will work well with boost (or other template heavy libraries) or do I need to code in visual studio and just recompile under a posix system ?. I guess what I could do is hide the boost code I use behind my own objects in visual studio and then resume development on Posix where it can index my objects nicely. It's depressing how bad the code completion engines are in non-Microsoft editors for C++ :(. Are there any mechanisms in c++0x to make the template code easier to parse for naive code-completion engines ? Regards Hassan

3 4

lock-free shared_ptr on solaris
by Frank Meerkötter 01 Sep '09

01 Sep '09

Hello, from looking at [1] i understood that there is no lock-free implementation of shared_ptrs on solaris. When snooping around in the source i noticed that there is a ./smart_ptr/detail/atomic_count_solaris.hpp It is using the solaris specific <atomic.h> to implement an atomic counter. frank@dexter:~/boost_1_40_0/boost$ find -type f | xargs grep atomic_count_solaris.hpp ./smart_ptr/detail/atomic_count_solaris.hpp:// boost/detail/atomic_count_solaris.hpp But apparently it is not in use. I am currently wondering why? KR, Frank [1] http://www.boost.org/doc/libs/1_40_0/libs/smart_ptr/shared_ptr.htm

2 2

Re: [Boost-users] [msm] Acceptance into boost?
by christophe henry 01 Sep '09

01 Sep '09

>I really admire the Boost.MSM library currently in the vault. I like it a lot better than the original FSM. Are there any plans to integrate the msm library into >an official Boost release?> >--------- >Robert Dailey Thanks for the feedback! I'm happy that you like it! Msm is right now in the review queue but I need a review manager and I have been very busy with msm 2.0 and therefore had no time to look for one. So I'd like to use the chance to ask if some experienced boost'ler would accept to be the review manager for msm and help me speed up the process a little. If someone would also be interested in playing with msm 2 as beta tester please contact me too :) Christophe _________________________________________________________________ More than messages–check out the rest of the Windows Live™. http://www.microsoft.com/windows/windowslive/

1 0

[Test] data_access_test && common_layer::const_string && missing std::out_of_range exception
by Dmitry V. Krivenok 01 Sep '09

01 Sep '09

Hello! I'm trying to build boost-1.40.0 and have problems with Boost::Test. Please take a look at build log: ------------------------------------------------------------------------ common.mkdir /home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test common.mkdir /home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4 common.mkdir /home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug gcc.compile.c++ /home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.o gcc.link /home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test testing.capture-output /home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.run ====== BEGIN OUTPUT ====== Running 6 test cases... ../../libs/test/example/const_string_test.cpp(71): error in "data_access_test": exception std::out_of_range is expected *** 1 failure detected in test suite "const_string test" EXIT STATUS: 201 ====== END OUTPUT ====== LD_LIBRARY_PATH="/usr/local/bin:/usr/local/lib:/usr/local/lib32:/usr/local/lib64:$LD_LIBRARY_PATH" export LD_LIBRARY_PATH "/home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test" > "/home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.output" 2>&1 status=$? echo >> "/home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.output" echo EXIT STATUS: $status >> "/home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.output" if test $status -eq 0 ; then cp "/home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.output" "/home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.run" fi verbose=0 if test $status -ne 0 ; then verbose=1 fi if test $verbose -eq 1 ; then echo ====== BEGIN OUTPUT ====== cat "/home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.output" echo ====== END OUTPUT ====== fi exit $status ...failed testing.capture-output /home/krivenok/dev_builds/boost_1_40_0_build/boost/bin.v2/libs/test/example/const_string_test.test/gcc-4.4/debug/const_string_test.run... ...failed updating 1 target... ...updated 174 targets... ------------------------------------------------------------------------ The problem is: ../../libs/test/example/const_string_test.cpp(71): error in "data_access_test": exception std::out_of_range is expected I looked at line 71 in const_string_test.cpp: BOOST_CHECK_THROW( cs1.at( cs1.length() ), std::out_of_range ); This code is used to ensure that std::out_of_range is thrown in case of out of bound access to the string. However, common_layer::const_string doesn't provide such validation. operator[] and at() are identical in const_string: char operator[]( size_t index ) const { return m_begin[index]; } char at( size_t index ) const { return m_begin[index]; } I commented BOOST_CHECK_THROW out and now Boost::Test compiles w/o any errors. I think implementation of const_string::at() should be fixed.

2 1

[serialization] loading a map having a const mapped value type
by Marco Canini 01 Sep '09

01 Sep '09

Hi all, I'm unable to address this use case of the serialization library. I have a standard map in which the mapped value is const: map<string, const Protocol *> _table; My serialize is very simple: ar & _table; (the test case source code is attached) However, this can't be compiled as I get many errors related to the loading code inside boost::serialization: /usr/include/boost/archive/detail/iserializer.hpp:488: error: reinterpret_cast from type 'const Protocol**' to type 'void**' casts away constness /usr/include/boost/archive/detail/iserializer.hpp:491: error: no matching function for call to 'boost::archive::detail::load_pointer_type<boost::archive::text_iarchive, const Protocol*>::pointer_tweak(const boost::serialization::extended_type_info&, const Protocol*&, const Protocol&)' /usr/include/boost/serialization/access.hpp:109: error: passing 'const Protocol' as 'this' argument of 'void Protocol::serialize(Archive&, unsigned int) [with Archive = boost::archive::text_iarchive]' discards qualifiers /usr/include/boost/archive/detail/iserializer.hpp: In member function 'void boost::archive::detail::pointer_iserializer<T, Archive>::load_object_ptr(boost::archive::detail::basic_iarchive&, void*&, unsigned int) const [with T = const Protocol, Archive = boost::archive::text_iarchive]': /usr/include/boost/archive/detail/iserializer.hpp:299: error: invalid conversion from 'const void*' to 'void*' /usr/include/boost/archive/detail/iserializer.hpp:307: error: invalid conversion from 'const void*' to 'void*' /usr/include/boost/archive/detail/iserializer.hpp:307: error: initializing argument 1 of 'void boost::archive::detail::basic_iarchive::next_object_pointer(void*)' /usr/include/boost/serialization/access.hpp:123: error: invalid conversion from 'const void*' to 'void*' /usr/include/boost/serialization/access.hpp:123: error: initializing argument 2 of 'void* operator new(size_t, void*)' /usr/include/boost/serialization/access.hpp:123: error: no matching function for call to 'Protocol::Protocol()' /usr/include/boost/archive/detail/iserializer.hpp:555: error: invalid application of 'sizeof' to incomplete type 'boost::STATIC_ASSERTION_FAILURE<false>' /usr/include/boost/archive/detail/iserializer.hpp:555: error: invalid application of 'sizeof' to incomplete type 'boost::STATIC_ASSERTION_FAILURE<false>' Can somebody share his wisdom on this please? Thanks! -- Marco Canini

3 6

[mpl::print] Making mpl::print<> function
by Robert Ramey 01 Sep '09

01 Sep '09

I have the following which I expect to produce a compile time warning which includes the type name but it fails to do so. I found this in the C++ Template Metaprogramming book - but not in the MPL documentation. What am I missing here? Robert Ramey #include <boost/mpl/print.hpp> template<class T> int f(){ boost::mpl::print<T>; //static int x = g<T::value>(); return x; } struct A { BOOST_STATIC_CONSTANT(bool, value = false); }; ... int x = f<A>();

3 2

[msm] Acceptance into boost?
by Robert Dailey 01 Sep '09

01 Sep '09

I really admire the Boost.MSM library currently in the vault. I like it a lot better than the original FSM. Are there any plans to integrate the msm library into an official Boost release? --------- Robert Dailey

1 0

Iterator behaving like an indirect_iterator and a filter_iterator
by Teto 01 Sep '09

01 Sep '09

Hi everyone, I wanted to know if it was possible to have an iterator behaving like both an indirect_iterator and a filter_iterator. I've tried to without success. Here is a minimal code that compiles but crashes. ===================================== class CTest { public: CTest(int Value,int Id) : value(Value),id(Id) {}; int id; int value; }; std::vector<CTest*> vec; vec.push_back(new CTest(4,7)); vec.push_back(new CTest(4,1)); //I want an iterator that I could use like iter->id / iter->value and not (*iter)->id / (*iter)->value struct SPredicate { bool operator()( C& x) { return (-1 < x.id); } }; typedef boost::filter_iterator<SPredicate, CTest*> FilterIterator; FilteredIterator end(*vec.end()); for(FilteredIterator iter(*vec.begin());start != end; iter++){ std::cout << "id" << iter->id << "\tValue" << iter->m << std::endl; } ===================================== I'm new to boost and is very impressed by its possibilites. Hope I can understand the code better later. thanx matt

3 2

[mem_fn] return type
by Lowell McLinskey 01 Sep '09

01 Sep '09

I am having trouble understanding the return type of mem_fn. Is it possible to create a vector of this type, analogous to how one can create a vector of type mem_fun_t to hold the return values of mem_fun()? Here is an example of what I'd like to do. Thanks in advance. #include <vector> #include <functional> #include "boost/shared_ptr.hpp" #include "boost/mem_fn.hpp" class A { public: A(const int a) : a_(a) {} const int get() const {return a_;} private: int a_; }; int main(int argc, char** argv) { // I can do this std::vector<std::const_mem_fun_t<const int, A> > v; v.push_back(std::mem_fun(&A::get)); int i = v[0](new A(4)); // and this boost::shared_ptr<A> p(new A(7)); int j = boost::mem_fn(&A::get)(p); // but how do I do this? // std::vector< WHAT GOES HERE > w; // w.push_back(boost::mem_fn(&A::get)); // int k = w[0](p); return 0; }

3 3

[asio] What happens when a deadline_timer is deleted
by Bjarne Laursen 01 Sep '09

01 Sep '09

If I have a deadline_timer in my class and my class is deleted, the compleetion function will be called (with error code). But as the destructor have already been run I guess that the 'this' pointer will be invalid! Is this safe? What if my compleetion function is virtual? timer.async_wait(boost::bind(&MyClass::OnTimer, this, boost::asio::placeholders::error)); --

2 1

[Units] Runtime dimension check
by Thomas Taylor 01 Sep '09

01 Sep '09

Hi all! Is there an easy way to check if two quantities have the same dimension? E. g. a user enters a weight in tons and asks for a conversion to kilograms. So now at run time I would like to know if tons and kilograms have the same dimensions (i. e. are convertable) or not (illegal conversion). Thanks, Thomas

2 1

Problem detecting python
by Philippe Fremy 01 Sep '09

01 Sep '09

Hi, bjam does not seem to pick my python installation on windows. This is running on Windows XP, toolset gcc, boost 1.39, compiling from source with no changes. D:\program\boost_1_39_0>bjam --debug-configuration -d+2 --debug-building [...] notice: [python-cfg] running command '"C:\Python25\python" -c "from sys import *; print 'version=%d.%d\nplatform=%s\nprefix=%s\nexec_prefix=%s\nexecutable=%s' % (version_info[0],version_info[1],platform,prefix,exec_prefix,executable)" 2>&1'notice: [python-cfg] ...does not invoke a working interpreter notice: [python-cfg] No working Python interpreter found. The strange thing is that if I run the same command line, it works perfectly: D:\program\boost_1_39_0>"C:\Python25\python" -c "from sys import *; print 'version=%d.%d\nplatform=%s\nprefix=%s\nexec_prefix=%s\nexecutable=%s' % (version_info[0],version_info[1],platform,prefix,exec_prefix,executable)" 2>&1 version=2.5 platform=win32 prefix=C:\Python25 exec_prefix=C:\Python25 executable=C:\Python25\python.exe Any idea what confuses bjam ? I could not find any log file to see more details of what is going wrong... cheers, Philippe

5 8

Latex
by Dmitry Bufistov 01 Sep '09

01 Sep '09

\renewcommand{\baselinestretch}{0.98}

1 1

[MPL] Front of a set of types
by Marco Guazzone 01 Sep '09

01 Sep '09

Dear all, Consider this: ---[code]--- #include <boost/mpl/front.hpp> #include <boost/mpl/set.hpp> #include <boost/type_traits/is_same.hpp> #define BOOST_TEST_MODULE "boost::mpl::set tests" #define BOOST_TEST_DYN_LINK #define BOOST_TEST_MAIN #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_CASE( mpl_set ) { typedef boost::mpl::set<int,long,char> s; BOOST_CHECK( (boost::is_same<int, boost::mpl::front<s>::type>::value) ); // Test #1 BOOST_CHECK( (boost::is_same<long, boost::mpl::front<s>::type>::value) ); // Test #2 BOOST_CHECK( (boost::is_same<char, boost::mpl::front<s>::type>::value) ); // Test #3 } ---[/code]--- Reading the docs http://www.boost.org/doc/libs/1_40_0/libs/mpl/doc/refmanual/set.html the "front" of a set<t1,t2,...,tn> return the first element type in s which for me is t1 So what I expect is the test to fail on tests #2 and #3 and hence to succeed on test #1 Instead the test fails on tests #1 and #2 and succeeds on test #3. Looking inside the code I find out this is OK since a setN<T1,..,TN> is defined from TN and set{N-1}<T1,...,T{N-1}>, resulting in TN be the very front element Anyway, in my opinion this is counterintuitive. Maybe a note in the document would be helpful. What do you think? Thank you very much! Cheers, -- Marco

2 7

problem with asio
by pedro chaparro 01 Sep '09

01 Sep '09

hi everyone, i'm new with boost, i've try some examples and they work well but spacifically with programs that use asio libraries i've got some error when i try to compile them, below the line i use to compile, ill apreciate some help thnaks pdro7@ubuntu:~/Desktop$ c++ -I /home/pdro7/Desktop/boost_1_40_0 asio1.cpp -o asio1 /usr/lib/libboost_system-gcc43-mt-1_35.a /usr/lib/libboost_thread-gcc43-mt-1_35.a /usr/lib/libboost_date_time-gcc43-mt-1_35.a /usr/lib/libboost_regex-gcc43-mt-1_35.a /usr/lib/libboost_serialization-gcc43-mt-1_35.a // timer.cpp // ~~~~~~~~~ // // Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #include <iostream> #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> int main() { boost::asio::io_service io; boost::asio::deadline_timer t(io, boost::posix_time::seconds(5)); t.wait(); std::cout << "Hello, world!\n"; return 0; } -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

2 1

[Math] Fractional binomial_coefficient
by Ralf M. 01 Sep '09

01 Sep '09

Hi, the binomial coefficients are usually used with integers, but it is also possible to get the binomial coefficient of real values (cf. http://en.wikipedia.org/wiki/Binomial_coefficient ). Maybe this could be added to the boost math library. Here's a sample implementation using standard g++: template <class T> T Choose(T n, T k) { return exp(lgamma(n + 1.0) - lgamma(k + 1.0) - lgamma(n - k + 1.0)); } Examples using double or long double type: C(10.000000, 3.000000) = 120.000000000000 C(10.000000, 3.250000) = 143.236519908866 C(10.000000, 3.500000) = 166.719334273254 C(10.000000, 3.750000) = 189.361086655990 C(10.000000, 4.000000) = 210.000000000000 C(10.500000, 3.000000) = 141.312500000000 C(10.500000, 3.250000) = 171.461136142499 C(10.500000, 3.500000) = 202.979003906250 C(10.500000, 3.750000) = 234.620815915449 C(10.500000, 4.000000) = 264.960937500000

2 1

[BGL] backward warning
by Ralf Goertz 01 Sep '09

01 Sep '09

When compiling with gcc4.3 I get a backward warning from adjacency_list.hpp because it includes hash_set instead of unordered_set (Boost 1.39.0). Will this be fixed soon? Ralf

2 2