- Boost-users - lists.boost.org

[lambda] Writing pass-through 'standard' algorithms
by Robert Jones 21 Jul '08

21 Jul '08

I encountered this difficulty in the context of passing lambda functors, but on reflection I don't the lambda aspect particularly matters. Consider this templated function template <typename InputIterator, typename Predicate> inline bool all_if( InputIterator first, InputIterator last, Predicate predicate ) { return std :: find_if( first, last, std :: not1( predicate ) ) == last; } Obviously the intent is to enquire if all members of a range satisfy the predicate. Now, as is, this doesn't compile, because it needs ptr_fun() on the predicate, but then a couple of things come up. - ptr_fun( ) requires that it's argument is a pointer-to-function - I'd like my all_if( ) to permit functions or functors, including lambda functors How can this be done? Is it impossible to dress-up a standard algorithm in this way? Thanks, Rob. -- ACCU - Professionalism in programming - http://www.accu.org

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Re: [Boost-users] question on boost-compliant code conventions
by Alan M. Carroll 21 Jul '08

21 Jul '08

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[asio] Copying an asio::stream_buf question
by Graham Reitz 21 Jul '08

21 Jul '08

Is this a reasonable method to copy the contents of one asio::streambuf into another (i.e. in a copy constructor of a class that contains an asio::streambuf)? istreambuf_iterator<char> i( ostream_1.rdbuf() ); istreambuf_iterator<char> eos; // end-of-stream ostreambuf_iterator<char> o( ostream_2.rdbuf() ); std::copy( i, eos, o ); thanks, graham

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[format] error when used with DEBUG_NEW in VC7.1 MFC
by hongleij 21 Jul '08

21 Jul '08

when i comment these codes ,it will be OK. #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif ////////////////////souce code #include <iostream> #include <tchar.h> #define WIN32_LEAN_AND_MEAN // #pragma warning(disable:4200) // nonstandard extension used : zero-sized array in struct/union #pragma warning(disable:4244) // 'conversion' conversion from 'type1' to 'type2', possible loss of data #pragma warning(disable:4800) // 'type' : forcing value to bool 'true' or 'false' (performance warning) // Windows Header Files: #ifndef WINVER #define WINVER 0x0400 // 0x0400 == Windows 98 and Windows NT 4.0 (because of '_WIN32_WINDOWS=0x0410') #endif #ifndef _WIN32_WINNT #define _WIN32_WINNT 0x0400 // 0x0400 == Windows NT 4.0 #endif #ifndef _WIN32_WINDOWS #define _WIN32_WINDOWS 0x0410 // 0x0410 == Windows 98 #endif #ifndef _WIN32_IE #define _WIN32_IE 0x0400 // 0x0400 == Internet Explorer 4.0 -> Comctl32.dll v4.71 #endif #define _ATL_CSTRING_EXPLICIT_CONSTRUCTORS #define _AFX_ALL_WARNINGS #include <afxwin.h> #include <afxext.h> #include <afxdisp.h> //#include <afxdtctl.h> #ifndef _AFX_NO_AFXCMN_SUPPORT #include <afxcmn.h> #endif // _AFX_NO_AFXCMN_SUPPORT #include <winsock2.h> #define _WINSOCKAPI_ #include <afxsock.h> #include <afxdhtml.h> #include <afxmt.h> #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif #include <boost/format.hpp> void ipAddressToString(const unsigned int ip, std::string &str) { //char temp[64]; //_snprintf(temp,sizeof(temp),"%ld.%ld.%ld.%ld", // ((ip >> 24) & 0xFF), // ((ip >> 16) & 0xFF), // ((ip >> 8) & 0xFF), // ((ip ) & 0xFF) ); //str = temp; str = boost::str( boost::format("%ld.%ld.%ld.%ld") % ((ip >> 24) & 0xFF) % ((ip >> 16) & 0xFF) % ((ip >> 8) & 0xFF) % ((ip ) & 0xFF) ); } class A {}; int _tmain(int argc, _TCHAR* argv[]) { std::string str; ipAddressToString(0xf1c2d3e4,str); int *p = new int(32); // A *q = new(p)(A); return 0; } ////////////////////////errors e:\boost_1_35_0\boost\optional\optional.hpp(315) : error C2061: syntax error : identifier 'm_storage' e:\boost_1_35_0\boost\optional\optional.hpp(314) : while compiling class-template member function 'void boost::optional_detail::optional_base<T>::construct(boost::optional_detail::optional_base<T>::argument_type)' with [ T=boost::io::detail::locale_t ] e:\boost_1_35_0\boost\optional\optional.hpp(455) : see reference to class template instantiation 'boost::optional_detail::optional_base<T>' being compiled with [ T=boost::io::detail::locale_t ] e:\boost_1_35_0\boost\format\internals.hpp(56) : see reference to class template instantiation 'boost::optional<T>' being compiled with [ T=boost::io::detail::locale_t ] e:\boost_1_35_0\boost\format\internals.hpp(57) : see reference to class template instantiation 'boost::io::detail::stream_format_state<Ch,Tr>' being compiled Build log was saved at "file://c:\Documents and Settings\jiang\桌面\Voip\kademlia\Debug\BuildLog.htm" Kad - 1 error(s), 1 warning(s)

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Spirit: skip parser and rules
by Alessandro Re 21 Jul '08

21 Jul '08

Hello, I've this code: // w and space_signaler are a function objects which print out some info. bool read_str(const char *in, StrList &w) { rule<> identifier = +alnum_p; rule<> statement = identifier[w] >> ch_p(';')[w]; return parse( in, (statement)[w], space_p[space_signaler] // Called for initial spaces only ).full; } Well, I don't understand why if i use (statement)[w] where signaled, the space_signaler is never called for non-initial spaces, while if i write directly the rule, it does correctly: return parse( in, (identifier[w] >> ch_p(';')[w])[w], space_p[space_signaler] // Called for every space ).full; In the latter case, it parses (skipping spaces) inputs like: "hello;" "hello ;" " hello ; " while in the former it parses correctly inputs like " hello;" "hello;" disallowing spaces between the word and the semicolon. Can someone explain me why does this happens? Thanks very much

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question on boost-compliant code conventions
by Ákos Maróy 21 Jul '08

21 Jul '08

Hi, This is probably a lame question, but I have some open issues I don't know how are handled in contemporary C++ style, for example with using boost coding convetions. I've been using the CamelCase naming convention from Java recently, where the issues below are non-issues actually. for example: - how do I create an instance of the same name as its type? in CamelCase: class Foo; Foo foo; in C++: class foo; foo foo; // won't compile what's the solution here? add some prefix to the instance's name? - how do I declare accessor functions to private members? in Java / CamelCase: class Foo { private int bar; public int getBar() { return bar; } }; in C++: class foo { private: int bar; public: int bar() const { return bar; } // won't compile }; should I put some prefix to the private member's name? Sorry for the lame questions :) But I just want to follow the guideline of 'in Rome, do as the Romans do' :) Akos

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[spirit] reading vector of string
by Christian Henning 21 Jul '08

21 Jul '08

Hi there, can I use push_back_a with std::vector<std::string>? I want something like this: std::vector< std::string > lines; rule<> l_entry = blanks_p >> *print_p[push_back_a( lines )] >> blanks_p >> eol_p; Regards, Christian

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Fusion transform question
by Joel FALCOU 21 Jul '08

21 Jul '08

I started porting over some old codes that used hand-made MPL<->concrete object code to Fusion. I'm currently trying to have the following to work with no results so far : struct make_arg { template<class Type> struct result { typedef typename boost::add_reference<typename boost::add_const<Type>::type >::type type; }; }; template<class Args> struct tree { typedef Args children; typedef typename bf::result_of::transform<Args,make_arg>::type contents; template<class T0,class T1> tree( const T0& t0 , const T1& t1 ) : mArgs( /* what to put here ??? */ ) {} template<size_t I> typename bf::result_of::at_c<contents,I>::type get() const { return bf::at_c<I>(mArgs); } contents mArgs; }; int main() { int k=3; float u=7.2; tree< bf::vector<int, float> > tree(k,u); return 0; } The question - as stated - in the code is how to simply build the mArgs member from the t0,...,tn arguments ? Thanks in advance. -- Joel FALCOU Research Engineer @ Institut d'Electronique Fondamentale Université PARIS SUD XI France

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[Boost.thread] Interruption points ?
by Ruediger Berlich 21 Jul '08

21 Jul '08

Hi there, just a short question: http://www.boost.org/doc/libs/1_35_0/doc/html/thread/thread_management.html… lists the following interruption points: * boost::thread::join() * boost::thread::timed_join() * boost::condition_variable::wait() * boost::condition_variable::timed_wait() * boost::condition_variable_any::wait() * boost::condition_variable_any::timed_wait() * boost::thread::sleep() * boost::this_thread::sleep() * boost::this_thread::interruption_point() Is (and if so: why is) a lock on a mutex no interruption point ? Thanks and Best Regards, Ruediger

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Re: [Boost-users] [fusion] sequence conversion
by Zeljko Vrba 21 Jul '08

21 Jul '08

On Sun, Jul 20, 2008 at 07:34:29PM -0400, Daryle Walker wrote: > > I'm not really into the whole MPL scene myself, but I'll give you > examples where I used it. > Thanks for the long explanation.

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