- Boost - lists.boost.org

How to extract tuple element in lambda function?
by Iggy Veresov 23 Jan '05

23 Jan '05

Can anybody enlighten me, how to extract a tuple element in lambda function? A straight-forward approach of binding corresponding get<> member-function doesn't comple.. using namespace boost::lambda; boost::tuple<int,int> t(1,2); std::cout << bind(&boost::tuple<int,int>::get<0>, _1)(t); Thanks in advance! /Ig

1 0

Latest TR draft available
by Beman Dawes 23 Jan '05

23 Jan '05

The latest draft of the C++ Standard Library Technical Report is available. See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1745.pdf AFAIK, this is the version that will go to ISO for the long process of formal voting. Thus it is the one Boosters should use; it contains a lot of minor fixes that turned up during the final editing. --Beman

1 0

Re: [iterator] small feature request
by David Abrahams 23 Jan '05

23 Jan '05

Eric Niebler wrote: > The iterator_adaptor<> template has a base() function to access the > underlying iterator. Well and good. However, iterator_adaptor<> doesn't > have a public typedef for the iterator type returned from this function. > Can it be added? > > Rationale: > Given some iterator of type T that is built of an unknown number of > adaptors, extract the underlying iterator. Consider: > > template<class Iter> > typename disable_if<is_adapted<Iter>,Iter>::type > base(Iter const & it) > { > return it; > } > > template<class D,class B,class V,class T,class R,class Di> > ?????????? > base(iterator_adaptor<D,B,V,T,R,Di> const & it) > { > return base(it.base()); > } > > I can't think of a way to write the return type of the second overload. > If iterator_adaptor had a nested typedef for its Base template > parameter, this would be very straightforward. Seems reasonable. Can you submit a patch? -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

3 6

Re [boost] Composites and Visitors
by Dave Handley 23 Jan '05

23 Jan '05

Jason Hise wrote: > I have no familiarity with these patterns, so my range of suggestions is > fairly limited. However, I did notice one way that you might be able to > make the composite more generic. Your composite library currently > forces the client to set up the hierarchy with raw pointers. Would it > be reasonable to ask that it allow smart pointers as well? It would > seem that this would be as easy as making the template parameter the > pointer type instead of the object type, as the plain object type > doesn't (appear to) be used anywhere. Thanks for the suggestion - I've actually been working on this, along with some other memory management policies. The smart pointer policy is relatively simple, although not quite as easy as making the template parameter a pointer type since I use new, delete and clone in the framework. Nevertheless, I should be able to get that policy up and running pretty quickly. I was also trying to create a further policy that used a single type and stored it by value rather than by pointer (like normal STL containers) - unfortunately, the policy for that is proving much harder than I originally thought. I'l probably abandon my second idea and just publish policies for smart_ptr and normal pointer versions of the code. > (btw, have you tried out my singleton longevity lifetime policy yet? ;) ) I've browsed the code, but unfortuantely, I've spent a week away on business so haven't had a time to use it in anger yet, or study the code in any detail. My first impression is that you have done a good job - but I'll get back later in the week with a more detailed review. Dave Handley

1 0

Help requested building and running tests
by Jody Hagins 23 Jan '05

23 Jan '05

I apologize in advance. I can not figure out how to get tests to build and run correctly from within subdirectories. The --builddir option does not seem to be honored, and the Jamfiles are so "simple" that I haven't a clue as to what is happening. To be honest, I have made several attempts at using bjam, but the only thing I can get to work is a toplevel make of everything. So, for all my own stuff, I have been using a mirror hierarchy and Makefiles (since that is what I have been using for the last 2 decades). However, I now want to get some code ready for submission (I have moved type_id and in the process have written a dynamic library wrapper as well). Unfortunately, I can not get my tests to integrate very well within boost. Thus, I humbly ask for any pointers and/or assistance in this regard. Thanks!

7 9

Extra '\r' in lines
by Victor A. Wagner Jr. 23 Jan '05

23 Jan '05

The following lines have an extra '\r' before then "newline" in them. For reasons that are obscure (to me, I'm SURE there's a great marketing reason for this) VC-8.0 bitches about them being Mac files and refuses to compile them. File: T:\Projects\boost\libs\test\example\unit_test_example3.cpp File: T:\Projects\boost\libs\test\test\class_properties_test.cpp File: T:\Projects\boost\libs\test\test\errors_handling_test.cpp File: T:\Projects\boost\libs\test\test\fixed_mapping_test.cpp File: T:\Projects\boost\libs\test\test\parameterized_test_test.cpp File: T:\Projects\boost\libs\test\test\result_report_test.cpp File: T:\Projects\boost\libs\test\test\test_case_template_test.cpp File: T:\Projects\boost\libs\test\test\test_fp_comparisons.cpp File: T:\Projects\boost\libs\test\test\test_tools_test.cpp of course this causes problems in my regression runs using VC-8.0 Victor A. Wagner Jr. http://rudbek.com The five most dangerous words in the English language: "There oughta be a law"

3 5

Composites and Visitors
by Dave Handley 23 Jan '05

23 Jan '05

Following on from a post I made about a week ago regarding a templatised composite, a version of an acyclic visitor, and a version of this visitor designed to visit composite trees, I have uploaded these files to the boost sandbox in a file called composite_visitor.zip. I have included some basic instructions on how to use the classes. I would appreciate some feedback on whether there would be any interest in submitting these for inclusion in Boost. Also I would be interested in any thoughts regarding potential improvements to the templates. Thanks Dave Handley

2 1

Re: [boost] [multi-index] partial_std_allocator_wrapper constructor
by JOAQUIN LOPEZ MU?Z 22 Jan '05

22 Jan '05

----- Mensaje original ----- De: Daniel James <daniel(a)calamity.org.uk> Fecha: Sábado, Enero 22, 2005 7:08 pm Asunto: [boost] [multi-index] partial_std_allocator_wrapper constructor > Hi, > > I'm using the multi-index allocator utilities for the unordered > associative containers implementation. Because > partial_std_allocator_wrapper can't be constructed from the > standard > allocator, I get an error when I use a standard allocator as a > constructor parameter. I believe it also prevents this with the > multi-index library. > > Would it be possible to apply the attached patch to fix this? (Or > is > there another way?) Umm... Seems you're right. Give me a couple of days (I don't have write CVS access now) and I'll check your fix in. Thanks for the contribution, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

1 0

Linker errors with basic_string
by Andreas Löffler 22 Jan '05

22 Jan '05

Hi there, I'm getting linker errors when I'm trying to compile my application with VS.2003 and boost-1.32. The application uses a DLL which doesn't use parts of the STL or boost, only the application itself and a static library (which contains the major parts of the code) are using boost, STL and MFC code. mfcie error LNK2019: Nicht aufgelöstes externes Symbol '"class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@ABV?$basic_str ing@DU?$char_traits@D@std@@V?$allocator@D@2@@0@@Z)', verwiesen in Funktion '"public: class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall MemoryInfo::getTotalRam(void)const " (?getTotalRam@MemoryInfo@@QBE?AV?$basic_string@DU?$char_traits@D@std@@V?$all ocator@D@2@@std@@XZ)' mfcie error LNK2001: Nichtaufgelöstes externes Symbol "class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@ABV?$basic_str ing@DU?$char_traits@D@std@@V?$allocator@D@2@@0@@Z) mfcie error LNK2001: Nichtaufgelöstes externes Symbol "class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@ABV?$basic_str ing@DU?$char_traits@D@std@@V?$allocator@D@2@@0@@Z) mfcie error LNK2019: Nicht aufgelöstes externes Symbol '"__declspec(dllimport) class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,char const *)" (__imp_??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@PBD@Z)', verwiesen in Funktion '"public: virtual void __thiscall DriveInfo::determineDriveInfo(unsigned int const &)" (?determineDriveInfo@DriveInfo@@UAEXABI@Z)' mfcie error LNK2001: Nichtaufgelöstes externes Symbol "__declspec(dllimport) class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,char const *)" (__imp_??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@PBD@Z) mfcie error LNK2019: Nicht aufgelöstes externes Symbol '"__declspec(dllimport) class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,char const *)" (__imp_??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@PBD@Z)', verwiesen in Funktion '"protected: virtual void __thiscall OSInfo::determineOSInfo(void)" (?determineOSInfo@OSInfo@@MAEXXZ)' mfcie error LNK2001: Nichtaufgelöstes externes Symbol "__declspec(dllimport) class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,char const *)" (__imp_??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@PBD@Z) mfcie error LNK2019: Nicht aufgelöstes externes Symbol '"__declspec(dllimport) class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,char)" (__imp_??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@D@Z)', verwiesen in Funktion '"public: virtual void __thiscall DriveInfo::determineDriveInfo(unsigned int const &)" (?determineDriveInfo@DriveInfo@@UAEXABI@Z)' mfcie error LNK2019: Nicht aufgelöstes externes Symbol '"__declspec(dllimport) bool __cdecl std::operator==(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (__imp_??8std@@YA_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2 @@0@0@Z)', verwiesen in Funktion '"public: enum CpuStats::e_CPUVENDORS __thiscall CpuStats::getVendor(void)const " (?getVendor@CpuStats@@QBE?AW4e_CPUVENDORS@1@XZ)' mfcie fatal error LNK1120: 4 unaufgelöste externe Verweise Any ideas? Greetings Andrew

2 1

null
by Jason Hise 22 Jan '05

22 Jan '05

Just wondering if there was any interest in a better null, or if such a thing existed in boost already. The code is relatively simple: class null { public: explicit null ( void * ) { } ~ null ( ) { } template < typename T > operator T * ( ) { return 0; } }; null null ( 0 ); Example usage: int * p = null; // ok int i = null; // error: null cannot be converted to an int -Jason

6 10