February 2004 - Boost - lists.preview.boost.org

[MPL, TypeTraits] Absurd template nesting on GCC 2.95
by Jonathan Turkanis 09 Feb '04

09 Feb '04

Hi all, I'm working on some code which if naively implemented would involve deep template nesting. Since I can't get a version using MPL algorithms to work on BCC 5.5.1 or VC6 , I wrote out the algorithm with hand-coded loop unrolling. It worked beautifully on a whole bunch of compilers, but when I tried it on GCC 2.95 I found I had to set the template nesting depth to 34 to get it to compile. The same code worked on GCC 3.2 with the depth restricted to 11. After making a few changes, I got the depth on GCC 2.95 (and 3.2) down to 7. One of the changes I made was to switch from using is_based_and_derived to a hand-rolled version restricted to a particular base type. This last change eliminated 11 levels of nesting on GCC 2.95 and 4 on GCC 3.2, although is_based_and_derived had been used in only one place, with fairly simple types, at the center of the algorithm. So I am wondering: is GCC 2.9x known to to be wasteful with respect to template nesting? Also, are the workarounds for GCC 2.9x in Type Traits or MPL known to add a lot of extra template nesting? Jonathan

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BGL random algorithms and Boost.Random number generators.
by Cromwell Enage 08 Feb '04

08 Feb '04

The boost::uniform_int random number generator in Boost.Random was compatible with the BGL random algorithms in version 1.30.2 but can no longer be directly passed to them in version 1.31.0. Should I work around this issue, as I'm currently doing, or will there be some sort of fix? TIA! Cromwell Enage __________________________________ Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online. http://taxes.yahoo.com/filing.html

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function (object) return and argument metafunctions?
by David Abrahams 08 Feb '04

08 Feb '04

Hi, I know we've discussed this in the past, but did we ever settle on an interface for deducing the return and parameter types of function (object)s? Doug G.'s result_of<F(a,b)> template works for return types, but it's not very portable and is not even in Boost proper AFAIK. Many function objects and all function pointers have specific (non-templated) parameter types, and it would be extremely valuable to be able to deduce those as well. It's hard to believe that with all the functional programming libraries we have, there's no standardized facility for this sort of deduction. -- Dave Abrahams Boost Consulting www.boost-consulting.com

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RE: [boost] future of boost.threads
by Bennett, Patrick 08 Feb '04

08 Feb '04

Honestly, I'd suggest you just use ACE for threading/synchronization primitives. It's available for a large number of platforms and is heavily used and frequently updated. I like Boost a lot, but I think some people are trying to make Boost more than (IMO) it should be. People discussing efficient io dispatch techniques for example would be better served to just use ACE, which already does many of these things extremely well. (http://www.cs.wustl.edu/~schmidt/ACE.html) Just my (possibly unwanted) $.02. Patrick -----Original Message----- From: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Burc Arpat Sent: Thursday, February 05, 2004 5:14 AM To: boost(a)lists.boost.org Subject: [boost] future of boost.threads i was actually waiting for the rush of the new release to go away to ask this question: i have seen some recent discussions regarding the threads library and from what i gathered there are plans to start working on it again. but, it also seems the original owner of the lib has disappeared from the list here at the petroleum eng. dept. of stanford university, we use boost rather heavily and lately we started into looking parallelization issues. we, of course, would like to use a cross-platform library such as boost.threads but are a bit worried about the future of it so, i guess, the questions are: is there gonna be a new release of boost.threads? if so, are there any plans to change the interface to a degree that it will require significant changes in the user code? with that said, let me also state that, i will be more than glad to give full test support for the library if any changes are being considered burch

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Slight problem testing BOOST_STATIC_ASSERT
by Daryle Walker 08 Feb '04

08 Feb '04

Maybe I missed something in my quick glance.... I just downloaded Boost 1.31.0, and took random looks/comparisons at some of the files. The test files for BOOST_STATIC_ASSERT have something like: BOOST_STATIC_ASSERT( sizeof(int) == sizeof(char) ) // should fail Whoever wrote this should know that platforms that have EVERY built-in type be the same size are allowed! The only guarantee for size differences would be to use "T" v. "T[L]" or "T[N]" v. "T[M]", where N and M are different compile-time constants and L cannot be 1. -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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gcc on win32: RC_1_31_0
by Johannes Brunen 08 Feb '04

08 Feb '04

Hi, can anyone please tell me the status of the following gcc failures on win32 RC_1_31_0: date_time testmicrosec_time_clock integer cstdint_test iterator interoperable_fail math octobion_test math quaternion_test test error_handling_test Won't these errors be solved for the upcomming release? I can't found any tests of spirit and mpl for the win32 gcc (mingw) platform. Aren't there any? It would be fine to have a regression table of all boost libraries for a particular platform. With kind regards Johannes

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[regression][regex] regex_timer.test hangs
by Ronald Garcia 08 Feb '04

08 Feb '04

Hi, I'm running the boost regression tests using a modified "run_tests.sh" on a Windows XP machine using cygwin, and it seems that one of the tests, regex_timer.test hangs. This has happened for both "msvc" and "vc7" toolsets. I'm curious if anyone else has run into this and what may be the possible fix. Having looked at the actual program run, I found that I can make regression testing continue by typing "quit" and enter, which I presume the program takes as input at that point. Any hints on this would be helpful. ron

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[function] bug in docs?
by Angus Leeming 08 Feb '04

08 Feb '04

doc/html/class.boost.function_base.html 1. bool empty() const; Returns: true if this has a target, and false otherwise. Throws: Will not throw. Surely it returns true if the boost::function var has *no* target? Regards, Angus

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Re: future of boost.threads
by Burc Arpat 07 Feb '04

07 Feb '04

patrick, thanx for the suggestion. i am actually a fan of ace myself and i have happily used it before the problem is: nowadays it is becoming more and more common for non-cs depts. to try and write reusable, near-commercial quality code. this is true at least for some major private universities that i know of. that typically happens because companies who supply research funds expect to see software that is immediately useful, not just proof of concept coding. in other words, we are supposed to deliver quality scientific c++ libraries and software that implements all the research that's going on in the dept. given that, sticking with a single 3rd party library for such fundamental tools makes sense for several reasons: (1) when a new student arrives, you tell him/her to go to boost.org and start reading and that's the only burden. you don't also say, "oh, also read about ace, etc.". these people do not need to be very fluent in c++ ( remember, we are talking about non-cs engineering students ) so it's only confusing to force them to use different interface styles. boost interfaces sometimes vary to but at least the overall 'feel' of them is unified and in sync with the standard library (2) when a company wants to use the code, they only need to download and compile boost and our code and nothing else. the less 3rd party dependency, the better (3) and, finally, it is much easier to justify the use of boost than any other library out there. i can simply say "some of their sub-libraries are gonna make it to the next standard" and "they have c++ standards committee members on board" and will persuade even the biggest anti-open-source zealot for the above reasons, we prefer to use a boost sub-library whenever we can rather than using some other 3rd party library regardless of how high quality it might be. 'hope this explains the situation ... everyone, thanks for the responses. i guess, this means, i can start using the lib and then incorporating the changes is not gonna be a big problem. great! one question, though: i understand thread cancellation is gonna be one of the topics to work on. to be honest, it is gonna be quite important for us in the future. do you think it will be safe to say at least an alpha level work on this issue will be available within the next 6 months? although i don't consider myself a threading guru, as i mentioned before, i'll help out as much as i can towards such a goal burch Bennett, Patrick <Patrick.Bennett <at> inin.com> writes: > > Honestly, I'd suggest you just use ACE for threading/synchronization > primitives. It's available for a large number of platforms and is > heavily used and frequently updated. > I like Boost a lot, but I think some people are trying to make Boost > more than (IMO) it should be. People discussing efficient io dispatch > techniques for example would be better served to just use ACE, which > already does many of these things extremely well. > (http://www.cs.wustl.edu/~schmidt/ACE.html) > > Just my (possibly unwanted) $.02. > > Patrick

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Re: [boost] Is the release boost_1_31_0.tar.gz file OK?
by Reece Dunn 07 Feb '04

07 Feb '04

Douglas Gregor wrote: >On Saturday 07 February 2004 09:30 am, Beman Dawes wrote: > > I've had a report that boost_1_31_0.tar.gz gets a checksum error halfway > > through unzipping. > > > > Has anyone else had a problem? Or used the file successfully? > >Works for me. I get the problem. I am using WinXP SP2 with a current version of cygwin and bzip2 version: bzip2, a block-sorting file compressor. Version 1.0.2, 30-Dec-2001. but have replicated the error with WinRAR. Using bzip2 -tvv I get: boost_1_31_0.tar.bz2: [1: huff+mtf rt+rld] [2: huff+mtf rt+rld] [3: huff+mtf rt+rld] [4: huff+mtf rt+rld] [5: huff+mtf rt+rld] [6: huff+mtf rt+rld] [7: huff+mtf rt+rld] [8: huff+mtf rt+rld] [9: huff+mtf rt+rld] [10: huff+mtf rt+rld] [11: huff+mtf rt+rld] [12: huff+mtf rt+rld] [13: huff+mtf rt+rld] [14: huff+mtf rt+rld] [15: huff+mtf rt+rld] [16: huff+mtf rt+rld] [17: huff+mtf rt+rld] [18: huff+mtf rt+rld] [19: huff+mtf rt+rld] [20: huff+mtf rt+rld] [21: huff+mtf rt+rld] [22: huff+mtf rt+rld] [23: huff+mtf rt+rld] [24: huff+mtf rt+rld] [25: huff+mtf rt+rld] [26: huff+mtf rt+rld] [27: huff+mtf rt+rld] [28: huff+mtf rt+rld] [29: huff+mtf rt+rld] [30: huff+mtf rt+rld] [31: huff+mtf rt+rld] [32: huff+mtf rt+rld] [33: huff+mtf rt+rld] [34: huff+mtf file ends unexpectedly Is this a Windows problem? Regards, Reece _________________________________________________________________ Express yourself with cool new emoticons http://www.msn.co.uk/specials/myemo

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