October 2002 - Boost-users - lists.preview.boost.org

RE: [Boost-Users] Re: Type traits direct compiler support
by Mark Storer 15 Oct '02

15 Oct '02

What exactly can't you do with existing techniques? I was Most Impressed by Modern C++ Design, and I don't recall any limits stated on what was possible... the whole concept is relatively new to me --Mark Storer Software Engineer Cardiff Software #include <disclaimer> typedef std::disclaimer<Cardiff> Discard;

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RE: [Boost-Users] Re: Running the Boost_1_29_0 regression tests
by Beman Dawes 15 Oct '02

15 Oct '02

At 12:02 PM 10/15/2002, Arjun Bijanki wrote: >"David Abrahams" writes: > >> "Arjun Bijanki" <arjunb(a)microsoft.com> writes: > >> > Hi, I'm having trouble running the Boost_1_29_0 regression tests. A >lot >> > >> >> Arjun, >> >> What are you doing to compile/link the tests? >> The supported method uses bjam. Have you tried that? >> If you use the -d+2 option you can look at the command-lines used and >> replicate them in whatever environment you like. >> >> -Dave > >Thanks. Previously, I was using /status/regression.cpp to generate the >status table; I'll try using bjam instead. We probably should have removed regression.cpp from the 1.29.0 release. The thought occurred to me, but that was before we decided to include all the new regression test components in the current CVS main trunk. Now that the main trunk has everything needed for the new tests, there is no reason to keep regression.cpp around. I'll remove it. --Beman

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RE: [Boost-Users] Re: Running the Boost_1_29_0 regression tests
by Arjun Bijanki 15 Oct '02

15 Oct '02

"David Abrahams" writes: > "Arjun Bijanki" <arjunb(a)microsoft.com> writes: > > Hi, I'm having trouble running the Boost_1_29_0 regression tests. A lot > > > > Arjun, > > What are you doing to compile/link the tests? > The supported method uses bjam. Have you tried that? > If you use the -d+2 option you can look at the command-lines used and > replicate them in whatever environment you like. > > -Dave Thanks. Previously, I was using /status/regression.cpp to generate the status table; I'll try using bjam instead. Arjun

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RE: [Boost-Users] Re: Type traits direct compiler support
by scleary＠jerviswebb.com 15 Oct '02

15 Oct '02

> -----Original Message----- > From: Edward Diener [mailto:eddielee@tropicsoft.com] > > > > From: Edward Diener [mailto:eddielee@tropicsoft.com] > > > > > > What does it mean in the type_traits documentation that "direct compiler > > > support for that traits class is required" ? I do not see that terminology > > > explained anywhere and am lost as far as to what it refers. > > > > It means that there is no known way to implement that class (in a > > Standard-compliant, portable manner). > > > > The type traits library is in a rather uncomfortable position, since it is > > essentially trying to add reflection to the C++ language after the fact. > > > > As currently implemented, the type traits library bends over backwards to > > try to provide as much as possible to as many different compilers as > > possible. But the simple fact is that it should not really be a library, > > but a part of the supplied language. > > > > Some type traits classes technically require compiler support. However, > > those classes will all try to take their "best guess" at the correct answer > > -- sometimes defaulting to a "safe" default if they can't figure out the > > correct answer. > > What sort of compiler support is being talked of here, since you mention > that it can't be done in a standard-compliant manner ? Does this mean > looking at preprocessor defines to determine the correct results, or what ? > It is the vagueness of the term "compiler support", which you did not > alleviate in your answer, which I am trying to clarify. "Compiler support" means "anything the compiler can give us so that we can implement that class correctly". It could be a specially-recognized preprocessor define, a quasi-class (e.g., SGI's type traits), a pragma, a keyword, or anything else that the compiler provides. -Steve

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Returning a tokenizer by value
by Brian_X7 15 Oct '02

15 Oct '02

Is there a problem with returning a tokenizer from a function? Here's what I've got: typedef boost::tokenizer< boost::char_separator<char> > tokenizer; tokenizer getTokens( istream& is ) { boost::char_separator<char> sep(",","", boost::keep_empty_tokens); std::string str; getline(is,str,'\n'); tokenizer toks( str, sep ); return toks; } .. tokenizer tokens = getTokens(input); tokenizer::iterator it = tokens.begin(); (*it) now contains garbage, interesting enough, iterating through the rest of the container works. when I move the processing of getTokens into the main code body the first token (*it) is then correct. Am I missing something fundamental here?

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RE: [Boost-Users] Type traits direct compiler support
by scleary＠jerviswebb.com 15 Oct '02

15 Oct '02

> -----Original Message----- > From: Edward Diener [mailto:eddielee@tropicsoft.com] > > What does it mean in the type_traits documentation that "direct compiler > support for that traits class is required" ? I do not see that terminology > explained anywhere and am lost as far as to what it refers. It means that there is no known way to implement that class (in a Standard-compliant, portable manner). The type traits library is in a rather uncomfortable position, since it is essentially trying to add reflection to the C++ language after the fact. As currently implemented, the type traits library bends over backwards to try to provide as much as possible to as many different compilers as possible. But the simple fact is that it should not really be a library, but a part of the supplied language. Some type traits classes technically require compiler support. However, those classes will all try to take their "best guess" at the correct answer -- sometimes defaulting to a "safe" default if they can't figure out the correct answer. -Steve

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[ANN] Quaternions, Octonions and Special Functions: please download from CVS.
by Hubert HOLIN 15 Oct '02

15 Oct '02

Somewhere in the E.U., le 15/10/2002 Bonjour Please note that due to some unfortunate circumstances beyond our control, the quaternion, octonion and special functions libraries which shipped with Boost 1.29.0 were not in the state they were meant to be in. You might want to download new versions of these libraries from the CVS in a couple of days. The version which should be present there adds compatibility with M$VCPP 7, and fixes things which CWPro 8 has broken in some circumstances. In a few days there will be another version with a user-contributed fix for gcc2.95.x and stlport on linux, among other things. Merci Hubert Holin Hubert.Holin(a)Bigfoot.com

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Running the Boost_1_29_0 regression tests
by Arjun Bijanki 14 Oct '02

14 Oct '02

Hi, I'm having trouble running the Boost_1_29_0 regression tests. A lot of tests don't appear to have main() defined. As an example, one of the tests fails with the following: *** libs/utility/ref_test.cpp *** ** Microsoft Visual C++ cl /Feboosttmp.exe /Zc:wchar_t /nologo /Zm400 /MDd /W3 /GR /GX /Zi /Od /GZ /I".." /D "WIN32" /D "_DEBUG" /D "_MBCS" /_CONSOLE" ../libs/utility/ref_test.cpp /link /incremental:no user32.lib ref_test.cpp LINK : fatal error LNK1561: entry point must be defined 0.80 s Return code: 2 Fail libs/utility/ref_test.cpp has the following lines: #define BOOST_INCLUDE_MAIN #include <boost/test/test_tools.hpp> But this doesn't seem to define a main() function like it did in Boost_1_28_0. Do I need to do some different kind of installation for Boost_1_29_0, or did I pick up wrong headers, or is this function missing? I downloaded Boost_1_29_0 from: http://boost.sourceforge.net/release/boost_1_29_0.zip Thanks! Arjun Bijanki Microsoft Visual C++

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Formal Review: The Spirit Parser Framework.
by John Maddock 14 Oct '02

14 Oct '02

The formal review for the Spirit Parser Framework begins today, and runs until the end of Sunday 20th October. Discussion should take place on the main boost developer list (boost(a)lists.boost.org), please state in your review whether you think the framework should be accepted into boost or not. The framework can be downloaded from: http://spirit.sourceforge.net/index.php?doc=download/v1_5.html Synopsis: ~~~~~~ Spirit is an object oriented recursive descent parser generator framework implemented using template meta-programming techniques. Expression templates allow us to approximate the syntax of Extended Backus Normal Form (EBNF) completely in C++. Parser objects are composed through operator overloading and the result is a backtracking LL(inf) parser that is capable of parsing rather ambiguous grammars. The Spirit framework enables a target grammar to be written exclusively in C++. Inline EBNF grammar specifications can mix freely with other C++ code and, thanks to the generative power of C++ templates, are immediately executable. In retrospect, conventional compiler-compilers or parser-generators have to perform an additional translation step from the source EBNF code to C or C++ code. Regards, John Maddock (Spirit review manager). http://ourworld.compuserve.com/homepages/john_maddock/index.htm

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Type traits direct compiler support
by Edward Diener 14 Oct '02

14 Oct '02

What does it mean in the type_traits documentation that "direct compiler support for that traits class is required" ? I do not see that terminology explained anywhere and am lost as far as to what it refers.

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