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Re: typeof: lvalue preserving
by Arkadiy Vertleyb 24 Jul '04

24 Jul '04

Giovanni Bajo wrote: >Arkadiy Vertleyb wrote: > > > One more addition to the typeof library is a macro, that, unlike > > BOOST_TYPEOF(), which removes top-level consts and references, > > attempts to be closer to the decltype, by preserving lvalue-ness of > > its argument: > > > > BOOST_TYPEOF_PRESERVE_LVALUE(expr) > > > > I do admit that the name is quite clumzy :( > > BOOST_DECLTYPE? Well, unfortunately, it's not exactly decltype :( In particular: int i; const int ci = 0; decltype BOOST_TYPEOF_PRESERVE_LVALUE -------- ---------------------------- i int int& ci const int const int& etc. It is calculated by binding a T& to the expression. If it can't be bound the type is the same as one returned by BOOST_TYPEOF. If it can, it's either reference or const reference, depending on the constness of T. Any suggestions how to make it closer to the real decltype? Arkadiy

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[Boost.Test] bug
by David Abrahams 24 Jul '04

24 Jul '04

This is with mingw-2.0 c:\boost\libs\test\build\../src/test_tools.cpp:37: `wcscmp' is already declared in this scope #if defined( __GNUC__ ) && defined( BOOST_NO_CWCHAR ) namespace std { using ::wcscmp; } <===================== here #endif -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

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What is it with boost and tinyurl?
by Miro Jurisic 24 Jul '04

24 Jul '04

It seems to me that boost developers are particularly enamored with tinyurl. While I agree that there are cases when tinyurl is a good thing, I can't but think that in many cases where it's used on boost lists it does more harm than good. Tinyurl (and similar services) discard valuable information from the URL. I often use information in the URL itself to judge whether the topic being discussed is of interest to me. Example: Useless: <http://tinyurl.com/4ghk7> Useful: <http://boost.sourceforge.net/regression-logs/cs-win32_metacomm/developer/pr… _options.html> ("Don't need to click if you are not interested in win32 regression of program options.") Useless: <http://tinyurl.com/yrotd> Useful: <http://lists.boost.org/MailArchives/boost/msg61026.php> ("Herein I refer to a previous thread on this mailing list.") Both of those examples were recently posted to the mailing list, and in both cases there was not enough context in the surrounding text for me to determine what the URL was about (without having to read several messages in the thread). I could name at least two other reasons for why tinyurl is not a great idea: first, it means that tinyurl.com can track my web access; second, if tinyurl is down, I am screwed. Neither of those two is as important to me as the reason I outlined above, though. Finally, URL line wrapping is a well-understood problem, with a recommended practice (namely, enclosing URLs in text inside <>, as I did above) codified in the current URL RFC. Every email and usenet client I am aware of does the right thing with line-wrapped URLs in angle brackets. If someone wants to convince me that tinyurl provides a valuable service to the community, I am listening. If not, I kindly request that those people who are in the habit of using tinyurl reconsider it. Thanks, meeroh -- If this message helped you, consider buying an item from my wish list: <http://web.meeroh.org/wishlist>

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Re:[boost] Re: Re: typeof: lvalue preserving
by Robert Ramey 23 Jul '04

23 Jul '04

Arkadiy Vertleyb wrote: >"Andy Little" <andy(a)servocomm.freeserve.co.uk> wrote >> ...I think spirit and lambda already have their own type deduction >> schemes, making it easy to implement there. >I am unaware of such schemes. You might check serialization as well. See extended_type_info.hpp and export.hpp Robert Ramey

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RE: [boost] Re: BOOST_FOREACH and break
by Rozental, Gennadiy 23 Jul '04

23 Jul '04

> There is a hidden variable in BOOST_FOREACH that tracks this > information, but it is scoped, so you can't get at it. (And > rightly so; > the scoping of hidden control variables is what makes BOOST_FOREACH > well-behaved.) BTW, while we are on topic. Your implementation uses code like this struct any_t {...}; template<typename T> struct static_any_t : any_t {...} template<typename T> static_any_t<T> foo(...); If( any_t const& ref = foo() ) { // here you are using ref } Is it indeed allowed in standard and ref is valid reference to temp? Gennadiy.

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Re:Re: [boost] Re: Re:Re: Re:Re: additional boost libraries?
by Robert Ramey 23 Jul '04

23 Jul '04

Rene Rivera wrote: Robert Ramey wrote: > >> a) If the compiler is an older compiler >> b) && SPIRIT_ROOT is defined to something not null >> c) || the compiler is a newer compiler. >> >> I think the build jamfile could altered to do this. I spent a little >> time at it but didn't immediately see how to do it. But I think it >> should be possible. Its probably trivial for a BJAM guru - so feel >> free anyone. Also it would be nice if it echoed a comment indicating >> that its skipping the XML components for lack of SPIRIT_ROOT. >Although it's now possible to do this, I would *not* recommend this as a >solution. The basic problem with changing the Jamfile to skip the building >is that it will only work if people use the Jamfile. That's fine for >testing, but not for release. Many people out there don't use BB for >building Boost. Well, if boost build isn't being used then there is no issue. Such users would just exclude libs/serialization/src/*xml*.cpp files from the library build. This is what I would like to see the boost build system do. Seems by far the simplest to me. Robert Ramey

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[multi_index] regression with GCC 4.1
by Joaquín Mª López Muñoz 23 Jul '04

23 Jul '04

The test at http://boost.sourceforge.net/regression-logs/cs-Linux-links.html#multi_inde… shows this message: Date: 2004-07-23 09:44 ../libs/multi_index/test/test_mpl_ops_main.cpp:20: internal compiler error: in size_of_die, at dwarf2out.c:6220 Please submit a full bug report, with preprocessed source if appropriate. See <URL:http://gcc.gnu.org/bugs.html> for instructions. Strangely enough, this test used to work for GCC 3.4.1, and I'm not aware of any significant change in the code of the library or any of its dependencies. Ideas, please? Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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BOOST_FOREACH and break
by Rozental, Gennadiy 23 Jul '04

23 Jul '04

Hi, I am trying to use construct similar to BOOST_FOREACH macro. In many cases I need to be able to detect whether loop was aborted with break or not. BOOST_FOREACH( ... ) { } // here if( aborted ) { .... } else { } Is there way to do so? Gennadiy.

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Regression reports at regression-logs/developer in-accessible.
by Rene Rivera 23 Jul '04

23 Jul '04

I get permission denied errors when trying to look at the regression outputs in .../developer/output. Seems someone forgot to make that directory+files world readable. -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org - grafik/redshift-software.com - 102708583/icq

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Re:[boost] Re: Re:Re: Re:Re: additional boost libraries?
by Robert Ramey 23 Jul '04

23 Jul '04

Edward Diener wrote: >> If you don't >> want to take the 15 minutes to do this, you can build with an older >> compiler and without spirit at all, you could easily modify the >> jamfile. Spirit is only used in the building of the library. >How can the jamfile be modified so that those who have an older compiler, >and don't need Spirit 1.6 for XML serialization, can build the >serialization library without Spirit 1.6 ? That was my point essentially. In order to compile with older compilers the variable SPIRIT_ROOT has to be defined and point to the root where spirit is installed. So the build jamfile would have to be modified so that that the modules for XML are build if and only if: a) If the compiler is an older compiler b) && SPIRIT_ROOT is defined to something not null c) || the compiler is a newer compiler. I think the build jamfile could altered to do this. I spent a little time at it but didn't immediately see how to do it. But I think it should be possible. Its probably trivial for a BJAM guru - so feel free anyone. Also it would be nice if it echoed a comment indicating that its skipping the XML components for lack of SPIRIT_ROOT. >BTW, your library is great and you should never feel that because you don't >hear from others about it that this indicates a lack of interest in users. >What it often indicates is that the library is working so flawlessly for >99.99% of its needs that users are content and do not need to send you any >reports about problems or errors. >From my vantage point it has become so large and intricate after accommodating all the "requirements" including features and portability that it's really hard for me to believe that it actually works all that well. Oh well. Robert Ramey

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