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[move] Move c-tor template
by Szymon Gatner 01 Apr '12

01 Apr '12

Hi, I am implementing custom smart pointer with move semantics and I am having problems with implementing move constructor with template param. In fact clone_ptr presented in docs suffers from that issue also. This code: class B {} class D: public B {} clone_ptr<D> makeD(); void main() { clone_ptr<B> b = makeD() // gives "error C2440: 'initializing' : cannot convert from 'clone_ptr<T>' to 'clone_ptr<T>'" } adding template <class U> clone_ptr(BOOST_RV_REF(clone_ptr<U>) p) //Move constructor : ptr(p.ptr) { p.ptr = 0; } to clone_ptr class does not help. Additional c-tor seems to be ignored. How to fix that? Cheers, Simon -- Szymon Gatner The Lordz Games Studio www.thelordzgamesstudio.com

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Re: [Boost-users] [boost] [test] Am I supposed to be able to use std::wstring in BOOST_CHECK_EQUAL?
by Daniel Trebbien 01 Apr '12

01 Apr '12

Hello Michael, Unfortunately, not yet. std::wstring support in BOOST_CHECK_EQUAL is Ticket #1136 (Let BOOST_CHECK_EQUAL support std::wstring): https://svn.boost.org/trac/boost/ticket/1136 Daniel Trebbien On 2012-04-01, Michael Kochetkov <michael.kv(a)gmail.com> wrote: > Hello, > Am I supposed to be able to use std::wstring in BOOST_CHECK_EQUAL? > I.e. > std::wstring s1,s2; > BOOST_CHECK_EQUAL(s1,s2); > > -- > Michael Kochetkov > > > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost >

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[parameter] Documented way to call arg-pack-accepting function generated by BOOST_PARAMETER_FUNCTION
by Jeremiah Willcock 01 Apr '12

01 Apr '12

Is there a documented way to call a function generated using BOOST_PARAMETER_FUNCTION with an explicit ArgumentPack? The "<f>_with_named_params" hinted at in the documentation does not seem to exist. -- Jeremiah Willcock

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newbie: my program can't find boost libraries
by sparsh mittal 31 Mar '12

31 Mar '12

Hello I am new to boost. In my RHEL linux (no root permission), my program does not find boost installation and says: *** Please install package libboost-filesystem to /home/myself/folder *** Please install package libboost-system to /home/myself/folder I installed latest boost using these instructions<http://www.boost.org/doc/libs/1_42_0/more/getting_started/unix-variants.htm…> . ./bootstrap.sh ----with-libraries=filesystem,system --prefix=/home/myself/folder ./bjam install Can you tell, what is wrong I am doing and anything to add in include path etc. My paths: echo $LD_LIBRARY_PATH /home/myself/folder/lib:/home/myself/ddrive/test/boost_1_49_0/stage/lib echo $CPLUS_INCLUDE_PATH /home/myself/folder/include/ My program has makefile: LD_LIBS += -lboost_filesystem -lboost_system (and others) Thanks and Regards Sparsh Mittal

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Boost container inspector in gdb (linux)...
by Shashank Prasad 31 Mar '12

31 Mar '12

I need to inspect the boost containers (unordered_map, unordered_set etc) in gdb (linux)? How can I do that? Similar stuff for STL containers is available at http://sourceware.org/gdb/wiki/STLSupport, but I couldn't find for Boost anywhere. Thanks a lot for your help!

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My homemade object pool
by 饭桶 31 Mar '12

31 Mar '12

Hi all Here is my objectpool implemention which inspired by boost pool. Which have following features. Features: 1.Allocate an object from pre-allocate memory, when free an object just put it back to pool. 2.Call object's contructor at pool memory allocating or get object from pool, or do nothing. 3.Call object's deconstructor when "delete" object if constructor's been calling at "new" object 3.Call object's deconstructor when destroy objectpool if constructor's been calling at memory allocating 4.Can pass an function object to be invoke when "new" object, this can be used as a constructor if object's constructor don't be invokded when "new" object 5.Thread safe can be enable/disable by tempalte parameter 6.Callback can be raw pointer is T is not inherit from enable_shared_from this can be shared_ptr vers vice. There are several tasks need to do, like the allnodesset can be generated at callring of foreach. Delegate memory allocating to allocator, etc.. The whole project and unit test can be found at https://maxsrecyclebin.svn.sourceforge.net/svnroot/maxsrecyclebin/objectpoo… Is there any comments? Thanks ////////////////////////////////////////////////////////////////////////////////////// #include <istream> #include <list> #include <boost/shared_ptr.hpp> #include <boost/bind.hpp> #include <set> #include <algorithm> #include <boost/type_traits.hpp> #include <boost/enable_shared_from_this.hpp> #include <boost/thread/pthread/mutex.hpp> namespace maxutility { enum InitialType {None,ObjInitial,PoolAllocate}; template <typename T> class DummyCallableObj { public: void operator ()(boost::shared_ptr<T> &ptr) { //do nothing } }; template<bool isthreadsafe> class obthreadlock; template<> class obthreadlock<true> { public: void lock(){obmutex.lock();} bool try_lock(){return obmutex.try_lock();} void unlock(){obmutex.unlock();} private: boost::mutex obmutex; }; template<> class obthreadlock<false> { public: void lock(){}; bool try_lock(){return true;}; void unlock(){}; }; template <typename T,bool isthreadsafe=false,typename InitalFunction=DummyCallableObj<T> > class ObjectPool { #define LOCAL_LOCK boost::lock_guard<obthreadlock<isthreadsafe> > lg(obthreadlock_); protected: /** * @brief Declaration for furture usage **/ typedef T Node; typedef std::list<char *> FRAGMENTTYPE; typedef std::list<Node *> NODELIST; public: ObjectPool(InitialType initialtype=ObjInitial,size_t initialsize=512,size_t maxsize=0) { busyCount=0; this->poolsize=0; this->initialtype=initialtype; this->maxsize=maxsize; extend(initialsize); } ObjectPool(InitalFunction initalFunction=DummyCallableObj<T>(), InitialType initialtype=PoolAllocate, size_t initialsize=512, size_t maxsize=0) //:ObjectPool(initialtype,initialsize,maxsize) //Delegating constructors, c++11 only { busyCount=0; this->poolsize=0; this->initialtype=initialtype; this->maxsize=maxsize; this->initalFunction=initalFunction; extend(initialsize); } ~ObjectPool() { if(0!=busyCount) throw new std::exception(); if(PoolAllocate==initialtype) for(Node *p:allnodes) p->~Node(); for(char *pFragment:fragments) delete pFragment; } virtual boost::shared_ptr<T> create() { LOCAL_LOCK; boost::shared_ptr<T> ptr(static_cast<T*>(getFreeNode()),boost::bind(&ObjectPool<T,isthreadsafe,InitalFunction>::free,this,_1)); initalFunction(ptr); return ptr; } bool empty() { return !busyCount; } size_t size() { return busyCount; } size_t capacity() { return poolsize; } template <typename FUNCTION> void foreach(FUNCTION f) { LOCAL_LOCK; NODELIST freenodes=this->freenodes; //make a local copy freenodes.sort(); NODELIST busynodes(allnodes.size()); typename NODELIST::iterator busynodesend=std::set_difference( allnodes.begin(),allnodes.end(),freenodes.begin(),freenodes.end(),busynodes.begin() ); for(typename NODELIST::iterator iter=busynodes.begin(); iter!=busynodesend; iter++) { invokeFunction<FUNCTION,Node, boost::is_base_of<boost::enable_shared_from_this<Node>,Node >::value >()(f,*iter); } } protected: template<typename _Function,typename N,bool isuseshareptr> class invokeFunction; template<typename _Function,typename N> class invokeFunction<_Function,N,false> { public: void operator ()(_Function __f,N *p) { __f(p); } }; template<typename _Function,typename N> class invokeFunction<_Function,N,true> { public: void operator ()(_Function __f,N *p) { boost::shared_ptr<N> ptr=p->shared_from_this(); __f(ptr); } }; protected: void free(T *p) { LOCAL_LOCK; if(!p) return; destroyObj(static_cast<Node*>(p),ObjInitial); //removeBusyNode(static_cast<Node*>(p)); freenodes.push_back(static_cast<Node*>(p)); busyCount--; } Node *getFreeNode() { Node *ptr=nullptr; if(freenodes.empty()) //no new free node if(!extend()) //try to extend return ptr; //false ptr=freenodes.front(); //now it must contain free node freenodes.pop_front(); constructObj(ptr,ObjInitial); busyCount++; return ptr; } bool extend(size_t size=0) { if((0!=maxsize&&poolsize>=maxsize&&poolsize!=0) ) return false; //we reach the maximum size //poolsize=0 first allocation //size=0 extend twice size of current size //poolsize=size=0 we got a problem size_t extSize=((0==poolsize)?size:2*poolsize); char *pFragment=new char[extSize*sizeof(Node)]; if(!pFragment) return false; fragments.push_back(pFragment); poolsize+=extSize; for(Node *p=(Node*)pFragment; extSize--; p++) { constructObj(p,PoolAllocate); freenodes.push_back(p); allnodes.push_back(p); } allnodes.sort(); return true; } void constructObj(Node *p,InitialType phase) { if(phase==initialtype) ::new(p)Node; } void destroyObj(Node *p,InitialType phase) { if(phase==initialtype) p->~Node(); } size_t poolsize; InitialType initialtype; size_t maxsize; FRAGMENTTYPE fragments; NODELIST freenodes; NODELIST allnodes; size_t busyCount; InitalFunction initalFunction; obthreadlock<isthreadsafe> obthreadlock_; }; };

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Unit concept
by Mario Charest 31 Mar '12

31 Mar '12

Everyone, I sent a message a couple of weeks ago but got no reply. I'm trying again. I've been reading and experimenting with Boost::Units. I have a hard time understanding how one deals with the same unit in different scale. Say I want to use thou, inch, feet, all interchangeably. My problem is I`m not sure which strategy to use. Pointers would be welcome.

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Can I use std::queue as ASIO io object for asynchronise operation?
by liubl 31 Mar '12

31 Mar '12

Hi, I want to implement a message queue between multiple thread, with multiple thread post message to the queue and one single thread process the message. I don't want the single processing thread to be blocked by the os when there is no message to be processed. I don't know if I can use ASIO lib to help me implement it. In my thought, the single processing thread read the queue asynchronisely and be invoked if there is one message ready on the queue, just like there is data ready on the socket. Is it doable? And is its performance better than the blocking method using conditional_variable? Regards, -Bruce

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[Concepts & EnableIf] Is void special?
by Robert Jones 31 Mar '12

31 Mar '12

Hi Peeps Can anyone cast any light on this... I want to write function which accepts a single pass range of X's, so something like this struct X { }; template <typename T> BOOST_CONCEPT_REQUIRES( (( boost::SinglePassRangeConcept<T> )), ( typename boost::enable_if<boost::is_same<typename boost::range_value<T>::type, X>, void>::type )) my_function( const T & range ); Is that a reasonable construction, or is there a better way to say it? Next, it doesn't seem to work. It does seem to work if the type to which enable_if resolves is anything except void, but not for void. Why is this? TIA - Rob.

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Python error
by Kraus Philipp 30 Mar '12

30 Mar '12

Hello, I build Boost with Python 3.2 and get this error: Building Boost.Build engine with toolset gcc... tools/build/v2/engine/bin.linuxx86_64/b2 Detecting Python version... 3.2 Detecting Python root... File "<string>", line 1 import sys; print sys.prefix ^ SyntaxError: invalid syntax Unicode/ICU support for Boost.Regex?... not found. Generating Boost.Build configuration in project-config.jam... I don't need the ICU support and it seems all libraries are build correctly Phil

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