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Re: BGL random algorithms and Boost.Random number generators.
by Cromwell Enage 09 Feb '04

09 Feb '04

Oops, forgot to check the docs! I'll update my code right away! Cromwell __________________________________ Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online. http://taxes.yahoo.com/filing.html

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mpl functions, pow_, root_, reciprocal
by Andy Little 09 Feb '04

09 Feb '04

Hi, Following preliminary ok of "pow" mpl metafunction by Alexey Gurtovoy... Here are some basic headers for mpl functions pow_, root_ and reciprocal. useage: boost::mpl::pow_<type,exponent>::type boost::mpl::root_<type,exponent>::type boost::mpl::reciprocal<type>::type Obvious type for the type and exponent is a static_rational type. For pow_ param order is same as runtime std::pow(x,y) , "root_" follows logically from pow_ .... but obviously ... pow_ could do the job) reciprocal also useful to represent 1/ type. I don't know enough mpl yet to provide generic examples except using the pqs types. If anyone else wants to have a go...? And of course docs :-) . Otherwise will get on with it asap. Feedback welcome. regards Andy Little ---------------------------------------------------------------- headers: #ifndef BOOST_MPL_POW_HPP_INCLUDED #define BOOST_MPL_POW_HPP_INCLUDED namespace boost { namespace mpl{ template <typename Type, typename Power> struct pow_ { typedef implementation_defined type }; }} //boost::mpl #endif //----------------- #ifndef BOOST_MPL_ROOT_HPP_INCLUDED #define BOOST_MPL_ROOT_HPP_INCLUDED namespace boost { namespace mpl{ template <typename Type, typename Power> struct root_ { typedef implementation_defined type; }; }} //boost::mpl #endif //----------------------------------- #ifndef BOOST_MPL_RECIPROCAL_HPP_INCLUDED #define BOOST_MPL_RECIPROCAL_HPP_INCLUDED namespace boost { namespace mpl{ template <typename Type> struct reciprocal{ typedef implementation_defined type; }; }} //boost::mpl #endif

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[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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