August 2005 - Boost-users - lists.preview.boost.org

Rationale for explicit ctors in boost smart pointers
by Matthias Kaeppler 28 Aug '05

28 Aug '05

Hi, I was wondering why e.g. boost:shared_ptr has an explicit constructor. This makes automatic conversion from T* to shared_ptr<T> impossible. The lack of the opposite conversion is covered by the FAQ and reasonable; however, I couldn't think of a good reason why I shouldn't be able to do something like this: std::set< boost::shared_ptr<Foo> > coll; coll.insert(new Foo); // error: No implicit conversion from Foo* to shared_ptr<Foo> Best regards, Matthias

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Problem of using Boost::regex
by Aaron 28 Aug '05

28 Aug '05

I want to make a program to grep all symbols in header file,like: #define CMD_BASE 0x10000000 #define CMD_GETFile (CMD_BASE + 0X00000001) /* Get a file from srv*/ A singl symbole definition line will be extract to three parts: 1. symbol itself 2. the value of a symbol, it's a signed 32-bit value 3. comments about the symbol I use the following pattern: std::string ptn = "\\s*#define\\s+([^\\s]+)\\s+([^/]*)([^\r\n]*)"; I hope this pattern could do what I want, but when I use grep to do the parsing, I got from above two lines: what[1]: CMD_BASE what[2]: 0x00001000#define CMD_GET_ALL_DOMAINNAME (CMD_IS_BASE+0x1) you see, the match extend to the new line! I noticed that when I use the same text, same pattern, doing the same thing in a vbscript program, if I set "Global match" option, this wouldn't happen. So, what's the counterpoint at boost::regex? My code here: bool OnGrepSingleLineSymbols(const boost::match_results<std::string::const_iterator>& what) { Symbol* sym = new Symbol; strcpy(sym->szSymbolName, what[1].str().c_str()); strcpy(sym->szSymbolInfo, what[3].str().c_str()); MakePretty(sym->szSymbolName); MakePretty(sym->szSymbolInfo); sym->nSymbolValue = ResolveMsgValue(sym->szSymbolName, what[2].str()); GetMsgSrv().AddSymbols(sym); return true; } void GrepSingleLineSymbols(CString& strSymContainer) { //#define ARN_SUCCESS 0l //ARRON!'HAHA //#define Arn_error1 ARN_SUCCESS + 0X0F //AARON ERROR1 static std::string ptn = "\\s*#define\\s+([^\\s]+)\\s+([^/]*)([^\r\n]*)"; static boost::regex re(ptn); std::string::const_iterator start, end; std::string text = strSymContainer; start = text.begin(); end = text.end(); boost::regex_grep(OnGrepSingleLineSymbols, start, end, re); }

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[Serialization] Class versioning & upward compatibilty
by Flavio Antonioli 27 Aug '05

27 Aug '05

Hello, is serialization class versioning supposed to allow old versions of a program that serializes an old version of a class to load files saved with a newer version that saves some extra data? It doesn't seem to be able to do it, but it would be a very useful feature. The docs mention the fact that new versions can read old version classes, they don't mention if old versions can load newer versions files. Unless I'm missing something, which is not unlikely, it should be relatively easy to implement, the xml readed should simply skip fields that it doesn't recognize. I'm using XML serialization, boost_1_33_0 dated 28-4-05, Visual C++ 7.1 & 8.0 beta 2. Thanks, Flavio Antonioli.

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[thread] RFE 1274707: Remove try/catch(...) in thread.cpp:thread_proxy()
by Matt Gruenke 27 Aug '05

27 Aug '05

I've submitted an RFE on this rather troubling behavior. I won't restate my case, as you can just view it here: http://sourceforge.net/tracker/index.php?func=detail&aid=1274707&group_id=7… Anyhow, it occurred to me that perhaps users with threads experience on other platforms (especially Windows) could comment on whether there's any similarly useful debugging behavior when exceptions are allowed to propagate outside of a thread (i.e. what the 'catch(...)' in libs/thread/src/thread.cpp:thread_proxy() specifically inhibits). If so, please update the RFE, rather than posting to the list. Matt Gruenke Software Engineer IntelliVid Corp.

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Re: [Boost-users] Boost.Thread memory leak reported
by Sohail Somani 26 Aug '05

26 Aug '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Peter Dimov > Sent: Friday, August 26, 2005 1:45 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Boost.Thread memory leak reported > > > Sohail Somani wrote: > > >>> Any dynamically allocated memory that isn't freed is a Bad > >> Thing imho. > >> > >> Because? > > > > Was it forgotten? Was it intentional? If the assumption is it will > > always be freed, then there is no ambiguity. > > Seems clearly intentional to me - the allocation is invoked > by call_once and > is a textbook implementation of a thread safe singleton. A > "this is not a > leak" comment may help. I understand its not a leak. There should atleast be a comment there saying we are not going to deallocate this memory that is allocated once. Its great you know, but part of this thread would have been avoided had there been that comment.

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Re: [Boost-users] Boost.Thread memory leak reported
by Sohail Somani 26 Aug '05

26 Aug '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Peter Dimov > Sent: Friday, August 26, 2005 1:07 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Boost.Thread memory leak reported > > > Christian Henning wrote: > > > But Peter, we do agree that there is problem and it should > be fixed, > > dont't we? > > I see no problems in the code. Any dynamically allocated memory that isn't freed is a Bad Thing imho.

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Re: [Boost-users] Boost.Thread memory leak reported
by Foster Gareth 26 Aug '05

26 Aug '05

> Because Purify is smart and doesn't report false leaks. > "False leaks"??

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Compile errors with format.hpp on AIX
by Rich Cook 26 Aug '05

26 Aug '05

Hi, Sorry for this repost; my first post was ignored or didn't make it to the list somehow. I am hoping the answer is not, "Forget it, boost doesn't work on AIX." But that is what I'm beginning to suspect. Or am I posting to the wrong list? Including boost/format.hpp on AIX in my project results in the following errors. Does anyone have an idea what is happening? I googled all over the place but found no help on the subject. Is boost only good with gcc? I don't think so, because the compiler for boost works with xlC. Hmm. xlC -c -g -I/g/g0/rcook/aix_5_64_fed/include -I/g/g0/rcook/ downloads/boost_1_33_0 MirandaReader.C -o aix_5_64_fed/MirandaReader.o "/g/g0/rcook/downloads/boost_1_33_0/boost/optional/optional.hpp", line 388.66: 1540-0217 (S) "T" is not a member of "locale". "/g/g0/rcook/downloads/boost_1_33_0/boost/optional/optional.hpp", line 388.10: 1540-0700 (I) The previous message was produced while processing "boost::optional_detail::optional_base<std::locale>::destroy_impl (is_not_reference_tag)". "/g/g0/rcook/downloads/boost_1_33_0/boost/optional/optional.hpp", line 362.9: 1540-0700 (I) The previous message was produced while processing "boost::optional_detail::optional_base<std::locale>::destroy()". "/g/g0/rcook/downloads/boost_1_33_0/boost/optional/optional.hpp", line 208.24: 1540-0700 (I) The previous message was produced while processing "boost::optional_detail::optional_base<std::locale>::~optional_base()". "/g/g0/rcook/downloads/boost_1_33_0/boost/optional/optional.hpp", line 130.7: 1540-0700 (I) The previous message was produced while processing "boost::optional_detail::optional_base<std::locale>::__dftbdt()". "/g/g0/rcook/downloads/boost_1_33_0/boost/optional/optional.hpp", line 471.5: 1540-0700 (I) The previous message was produced while processing "boost::optional<std::locale>::~optional()". "/g/g0/rcook/downloads/boost_1_33_0/boost/format/internals.hpp", line 38.9: 1540-0700 (I) The previous message was produced while processing "boost::io::detail::stream_format_state<char,std::char_traits<char> >::stream_format_state(char)". "/g/g0/rcook/downloads/boost_1_33_0/boost/format/internals.hpp", line 78.53: 1540-0700 (I) The previous message was produced while processing "boost::io::detail::format_item<char,std::char_traits<char>,std::allocat or<char> >::format_item(char)". "/g/g0/rcook/downloads/boost_1_33_0/boost/format/ format_implementation.hpp", line 121.40: 1540-0700 (I) The previous message was produced while processing "boost::basic_format<char,std::char_traits<char>,std::allocator<char> >::make_or_reuse_data(size_t)". "/g/g0/rcook/downloads/boost_1_33_0/boost/format/parsing.hpp", line 415.9: 1540-0700 (I) The previous message was produced while processing "boost::basic_format<char,std::char_traits<char>,std::allocator<char> >::parse(const string_type &)". "/g/g0/rcook/downloads/boost_1_33_0/boost/format/ format_implementation.hpp", line 64.9: 1540-0700 (I) The previous message was produced while processing "boost::basic_format<char,std::char_traits<char>,std::allocator<char> >::basic_format(const string_type &)". "MirandaReader.C", line 138.6: 1540-0700 (I) The previous message was produced while processing "MirandaDataSet::GetGridOrigin(long, Point<double> &)". gmake: *** [aix_5_64_fed/MirandaReader.o] Error 1 -- Richard Cook ✇ Lawrence Livermore National Laboratory Bldg-453 Rm-4037, Mail Stop L-557 7000 East Avenue, Livermore, CA, 94550, USA ☎ (925) 423-9605  (925) 423-6961 --- Information Management & Graphics Grp., Services & Development Div., Integrated Computing & Communications Dept. (opinions expressed herein are mine and not those of LLNL)

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Minor refinements for boost::rational
by Daniel Krügler 26 Aug '05

26 Aug '05

Hello, After a short view at the rational.hpp header I propose to perform the following changes: 1) As counterpart to the existing: bool operator!() const; one should definitly add: operator bool_replacement_type() const; with a proper (member function pointer) definition of bool_replacement_type. 2) The function template template <typename IntType> IntType lcm(IntType n, IntType m); should be defined as template <typename IntType> IntType lcm(IntType n, boost::call_traits<IntType>::param_type m); which makes sense in this case because m is not modified internally (in contrast to n) 3) The boost::rational IO should use proper templated extractors and inserters for those (most) compilers, which provide corresponding std IO libraries, such that #if defined (BOOST_NO_TEMPLATED_STREAMS) ... // current impl #else template<class CharType, class CharTrait, class IntType> inline std::basic_istream<CharType, CharTrait>& operator>>(std::basic_istream<CharType, CharTrait> &is, rational<IntType>&); template<class CharType, class CharTrait, class IntType> inline std::basic_ostream<CharType, CharTrait>& operator<<(std::basic_ostream<CharType, CharTrait> &os, const rational<IntType>&); #end Furtheron I propose to replace the helper class detail::resetter by boost::ios_flags_saver, or even better to remove it all all, because I assume, that the temporary unsetting of the skipws flag does not make much sense - Does it? I also propose to replace the current setting of ios_base::badbit (if widen('/') was not found) by the more appropriate setting of ios_base::failbit - This behaviour is in sync with std::complex and boost::tuple! Greetings from Bremen, Daniel Krügler

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MPL and conditional compilation
by Alan M. Carroll 26 Aug '05

26 Aug '05

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