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

[ANN] xpressive v2.1
by Eric Niebler 13 Jun '08

13 Jun '08

I've uploaded to the Boost Vault a new version of xpressive. This should be the version that ultimately becomes part of Boost 1.36. If anybody find problems, pls. let me know. New Features: * skip(), for specifying which parts of the input sequence to ignore when matching it against a regex. http://tinyurl.com/5xndnk (<http://boost-sandbox.sourceforge.net/libs/xpressive/doc/html/boost/xpressiv…>) * regex_replace() accepts formatter objects and formatter expressions, in addition to format strings. http://tinyurl.com/4c8rt4 (<http://boost-sandbox.sourceforge.net/libs/xpressive/doc/html/boost_xpressiv…>) * Range-based regex_replace() algorithm. http://tinyurl.com/4awtoh (<http://boost-sandbox.sourceforge.net/libs/xpressive/doc/html/boost/xpressiv…>) Bugs Fixed: * Crash when semantic actions are placed in look-aheads, look-behinds or independent sub-expressions. Thanks, -- Eric Niebler BoostPro Computing http://www.boostpro.com

1 0

Trying to understand the details of boost function
by Khandelwal, Amit 13 Jun '08

13 Jun '08

I am trying to understand the details of boost function. Below is the sample code that I am using. I was expecting the copy constructor to be invoked once. However, I see that it is called four times. I am trying to understand why does boost function need to have four copies of my objects. I am using boost version 1_33_1. Any thoughts/comments.. #include <iostream> #include <stdlib.h> #include <stdio.h> #include "boost/function.hpp" #include <map> using namespace std; class F { public: F() { cout << "Cons" << endl; } F(const F&) { cout << "Copy const" << endl; } F& operator=(const F&) { cout << "operator = " << endl; return *this; } int operator()(int a, int b) { cout <<" Sub" << endl; return a - b; } }; int main() { FUNC f = F(); } Output: Cons Copy const Copy const Copy const Copy const - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - This message is intended only for the personal and confidential use of the designated recipient(s) named above. If you are not the intended recipient of this message you are hereby notified that any review, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an offer to sell or as a solicitation of an offer to buy any financial product, an official confirmation of any transaction, or as an official statement of Lehman Brothers. Email transmission cannot be guaranteed to be secure or error-free. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such. All information is subject to change without notice. -------- IRS Circular 230 Disclosure: Please be advised that any discussion of U.S. tax matters contained within this communication (including any attachments) is not intended or written to be used and cannot be used for the purpose of (i) avoiding U.S. tax related penalties or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein.

2 1

Re: [Boost-users] how does one compile boost for MinGW?
by brad＠16systems.com 13 Jun '08

13 Jun '08

I run bjam.exe from the Msys shell... works great. bjam toolset=xxx --build-type=complete install

2 1

Boost::MultiIndex or std::map
by Sean Farrow 13 Jun '08

13 Jun '08

Hi: I am in a situation where by I need to be able to query an associative container. I need to fill the container before querying. The key is an integer and the vlaue is a std::string. Can I construct boost::multiIndex so as to allow key/value pairs to be entered at construction time or should I just use std::map and write a function. Any design advice apreciated. Note thi is going in to a dll with will return c-style types. Sean. __________ Information from ESET NOD32 Antivirus, version of virus signature database 3164 (20080606) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

5 6

Compiling Boost as static on MacOS (darwin)
by Germain BARRET 13 Jun '08

13 Jun '08

Hi people, I'm sure this subject as already been treated. I apologies for requesting it one time again. I try to compile boost libs as static libs (& multi-thread & universal & why not monolithic) and now I'm sure the ./configure compilation can't do that for me. So I began to go through the bjam way... but I'm absolutely not sure of the syntax and options to do what I want. (--build-type=static ???) My first try made me dynamic ".a" in many many folders and no ./include and no ./lib like in a standard install. And many error message when trying to copy files in the system lib directory (that I don't want to). What is the good way to compile boost on mac OS as static lib in the good folders ? (I've already done it on windows, I remember it much easyer, why ?) Germain

1 0

ublas: problem with having T& as reference type of matrix<T, L, DiskStorage>
by Maarten Nieber 13 Jun '08

13 Jun '08

Hi all, Recently I found out that the ublas matrix uses T& when creating a reference to a matrix element. This causes a problem for me, as I'm developing an ublas matrix that has its data on disk rather than in memory: ublas::matrix< double, row_major, DiskStorage > m; // stores data on disk I would like ublas::matrix to use the reference type that is declared by its storage type. typedef A::reference reference; My question is: is this a mistake in the design, or is there a reason why T& should always be the reference type of an ublas matrix? Thanks in advance, Maarten ps As an illustration, here is some code using the reference type of the DiskStorage class: DiskStorage aDiskStorage( 100 ); // create a disk storage with 100 elements DiskStorage::reference r = aDiskStorage[0]; r = 123.456; // writes 123.456 to disk

2 1

how does one compile boost for MinGW?
by Ákos Maróy 13 Jun '08

13 Jun '08

Hi, I know it's stated that compiling boost for MinGW is not supported, but still, I see some online resources about this. I tried several approaches, but none of them seem to work. Is there any authorotive information on how does it really work? The approaches I tried and which all failed so far: - try to compile boost running bjam.exe from a Windows Command Prompt - try to compile boost from an MSYS prompt, going through the ./configure && make && make install process (I can provide outputs in case they are needed) Any help would be appreciated. Akos

3 3

Compile errors with Phoenix closures
by Martin Apel 13 Jun '08

13 Jun '08

Hi all, I posted this issue a week ago to the Spirit mailing list only, but I got no reply. So I repost this onto the Boost mailing list as well: I tried to compile a Spirit grammar parsing a real number using closures under Microsoft Visual C++ 2005. The same grammar compiles fine on Linux using GCC 4.x. Boost version is 1.35.0 in both cases. As far as I understood, the error is caused by an assertion inside the closure class template: closure_frame_t& context() { assert(frame!=0); return frame.get(); } (line 352 of boost/spirit/phoenix/closures.hpp) Even if I define NDEBUG, Phoenix closures don't compile, because the return statement after the assertion returns a pointer to a closure_frame_t and not a reference. From my point of view, this is not really a compiler issue, but a bug in the header file boost/spirit/phoenix/closures.hpp. I do not understand, why GCC compiles this without any errors, because I think the code should not compile at all. Any help would be appreciated. Martin C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/closures.hpp(352) : error C2784: 'impl::make_binary3<phoenix::not_eq_op,BaseT0,BaseT1>::type phoenix::operator !=(const phoenix::actor<BaseT> &,const phoenix::actor<BaseT> &)' : could not deduce template argument for 'const phoenix::actor<BaseT> &' from 'phoenix::impl::closure_frame_holder<FrameT>' 3> with 3> [ 3> FrameT=phoenix::closure_frame<phoenix::closure<double,phoenix::nil_t,phoenix::nil_t>> 3> ] 3> C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/operators.hpp(1869) : see declaration of 'phoenix::operator !=' 3> C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/closures.hpp(352) : while compiling class template member function 'phoenix::closure_frame<ClosureT> &phoenix::closure<T0,T1,T2>::context(void)' 3> with 3> [ 3> ClosureT=phoenix::closure<double,phoenix::nil_t,phoenix::nil_t>, 3> T0=double, 3> T1=phoenix::nil_t, 3> T2=phoenix::nil_t 3> ] 3> C:\Programme\boost\boost_1_35_0\boost/spirit/attribute/closure.hpp(226) : see reference to class template instantiation 'phoenix::closure<T0,T1,T2>' being compiled 3> with 3> [ 3> T0=double, 3> T1=phoenix::nil_t, 3> T2=phoenix::nil_t 3> ] 3> E:\ma\new_arch\base/SpiritSupport.h(67) : see reference to class template instantiation 'boost::spirit::closure<DerivedT,T0>' being compiled 3> with 3> [ 3> DerivedT=NSBase::ExtRealParserClosure, 3> T0=double 3> ] 3>C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/closures.hpp(352) : error C2784: 'impl::make_binary2<phoenix::not_eq_op,T0,BaseT>::type phoenix::operator !=(T0,const phoenix::actor<BaseT> &)' : could not deduce template argument for 'const phoenix::actor<BaseT> &' from 'int' 3> C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/operators.hpp(1861) : see declaration of 'phoenix::operator !=' 3>C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/closures.hpp(352) : error C2784: 'impl::make_binary1<phoenix::not_eq_op,BaseT,T1>::type phoenix::operator !=(const phoenix::actor<BaseT> &,T1)' : could not deduce template argument for 'const phoenix::actor<BaseT> &' from 'phoenix::impl::closure_frame_holder<FrameT>' 3> with 3> [ 3> FrameT=phoenix::closure_frame<phoenix::closure<double,phoenix::nil_t,phoenix::nil_t>> 3> ] 3> C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/operators.hpp(1853) : see declaration of 'phoenix::operator !=' 3>C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/closures.hpp(352) : error C2676: binary '!=' : 'phoenix::impl::closure_frame_holder<FrameT>' does not define this operator or a conversion to a type acceptable to the predefined operator 3> with 3> [ 3> FrameT=phoenix::closure_frame<phoenix::closure<double,phoenix::nil_t,phoenix::nil_t>> 3> ] 3>C:\Programme\boost\boost_1_35_0\boost/spirit/phoenix/closures.hpp(352) : error C2440: 'return' : cannot convert from 'phoenix::closure_frame<ClosureT> *' to 'phoenix::closure_frame<ClosureT> &' 3> with 3> [ 3> ClosureT=phoenix::closure<double,phoenix::nil_t,phoenix::nil_t> 3> ]

1 0

error_code and error_category problem
by Berserker 13 Jun '08

13 Jun '08

In my project (using asio) I have something like this: void Foo::myCallback(const boost::system::error_code &e) { if(e == boost::asio::error::operation_aborted) { // bla bla... } } This call is made across a shared dll and I notice that for a "strange" reason e == boost::asio::error::operation_aborted was always false. I discover that when the temporary object boost::system::error_code is constructed from the constants boost::asio::error::operation_aborted the error_code's costructor take a pointer to a "error_category" and the comparison operator is (m_cat is an error_category pointer): inline friend bool operator==( const error_code & lhs, const error_code & rhs ) { return lhs.m_cat == rhs.m_cat && lhs.m_val == rhs.m_val; } In my situation (using shared modules) lhs.m_cat == rhs.m_cat points to differents memory regions (even if are of the same type "system_category") because of the static initialization in the function "get_system_category". The problem exist in the comparison operator of error_category too: bool operator==(const error_category & rhs) const { return this == &rhs; } I suggest to change the comparison criteria (for example using an enumerated value) _________________________________________________________________ Divertiti con le nuove EMOTICON per Messenger! http://intrattenimento.it.msn.com/emoticon

1 0

test case with ptr_map not compiling
by Christopher Harvey 13 Jun '08

13 Jun '08

This is a pretty simple question, so I'll just go ahead and paste the test case i wrote. The compile errors are right below it. (boost version: 1.34.1-r2) #include <utility> #include <boost/ptr_container/ptr_map.hpp> class Filter { public: virtual void blah() const = 0; }; class SpecificFilter : public Filter { public: SpecificFilter() : Filter() {} void blah() const { } }; int main() { boost::ptr_map<unsigned char, Filter> map; map[0].blah(); } /usr/include/boost/ptr_container/ptr_map_adapter.hpp: In member function 'typename boost::ptr_container_detail::associative_ptr_container<boost::ptr_container_detail::map_config<T, VoidPtrMap>, CloneAllocator>::reference boost::ptr_container_detail::ptr_map_adapter_base<T, VoidPtrMap, CloneAllocator>::insert_lookup(const typename boost::ptr_container_detail::associative_ptr_container<boost::ptr_container_detail::map_config<T, VoidPtrMap>, CloneAllocator>::key_type&) [with T = Filter, VoidPtrMap = std::map<unsigned char, void*, std::less<unsigned char>, std::allocator<std::pair<const unsigned char, void*> > >, CloneAllocator = boost::heap_clone_allocator]': /usr/include/boost/ptr_container/ptr_map_adapter.hpp:268: instantiated from 'typename boost::ptr_container_detail::associative_ptr_container<boost::ptr_container_detail::map_config<T, VoidPtrMap>, CloneAllocator>::reference boost::ptr_container_detail::ptr_map_adapter_base<T, VoidPtrMap, CloneAllocator>::operator[](const typename boost::ptr_container_detail::associative_ptr_container<boost::ptr_container_detail::map_config<T, VoidPtrMap>, CloneAllocator>::key_type&) [with T = Filter, VoidPtrMap = std::map<unsigned char, void*, std::less<unsigned char>, std::allocator<std::pair<const unsigned char, void*> > >, CloneAllocator = boost::heap_clone_allocator]' main.cc:24: instantiated from here /usr/include/boost/ptr_container/ptr_map_adapter.hpp:168: error: cannot allocate an object of abstract type 'Filter' main.cc:5: note: because the following virtual functions are pure within 'Filter': main.cc:7: note: virtual void Filter::blah() const I'm surprised it's not happy about the fact that blah is pure virtual because this is a pointer container so I thought that wouldn't be a problem. Side note: What happens when I try to access an element that doesn't exist, and what happens when I insert two elements with the same key? Thanks for reading, Chris.

2 1