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Code question on fusion tag_of.hpp
by Dave Steffen 09 Aug '12

09 Aug '12

Hi Folks During a recent bug hunt, we came across the following (Boost 1.49, fusion/adapted/std_tuple/tag_of.hpp): #include <tuple> namespace std { template <typename... Elements> class tuple; } We find this rather puzzling -- why is this here? As far as we can tell, this doesn't do anything. (Well, it did participate in a long, ugly compiler error about variadic templates, which is why we found it.) What are we missing? Thanks for any insight. -- Dave Steffen Software Engineer NUMERICA CORPORATION www.numerica.us (970) 461-2000 main (970) 612-2327 direct

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Re: [boost] [review] Multiprecision and uBlas
by John Maddock 09 Aug '12

09 Aug '12

>> Also running the tests for UBLAS with mp_number put in place of >> floats/doubles would be interesting. > > I've added modified versions of uBlas tests 1-7 to the multiprecision lib, > most of the tests pass, but there are two outstanding issues: > > * Test1: I had to disable a couple of tests because they trigger debug > assertons inside the STL. I get the same errors when testing with type > double, so I conclude it's a uBlas issue, not sure why they aren't > triggered in the regular regression tests though... > * Test3: I can't get this to compile, and the error are so inscrutable I > don't know what the issue is, I'd need some help from a uBlas expert to > figure those out. Hold on that was a mistake, test1 does pass, tests 3 and 7 don't compile for reasons I don't understand. I'd need some help from a uBlas expert to figure those out. John.

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[Algorithm] [Range] `is_sorted` is duplicate
by Michel Morin 08 Aug '12

08 Aug '12

Both Boost.Algorithm and Boost.Range have `is_sorted` function. Would it be better to deprecate Boost.Range's `is_sorted`? Also, Both Boost.Algorithm and Boost.Range have `iota` function. (In this case, Boost.Algorithm's `iota` returns void, but Boost.Range's `iota` returns the range.) Regards, Michel

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[context] doesn't build on 32-bit osx
by Luke Elliott 08 Aug '12

08 Aug '12

Hello Oliver There's actually already a ticket on this (https://svn.boost.org/trac/boost/ticket/7110 not from me) but since it's unassigned I thought I'd post here with a few more details. bjam address-model=32 -d+2 Performing configuration checks - x86 : yes Jamfile</Users/macpro/dev/checkouts/boost-trunk/libs/context/build>.gas ../../../bin.v2/libs/context/build/darwin-4.2.1/debug/address-model-32/architecture-x86/asm/fcontext_i386_sysv_macho_gas.o as -o "../../../bin.v2/libs/context/build/darwin-4.2.1/debug/address-model-32/architecture-x86/asm/fcontext_i386_sysv_macho_gas.o" "../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S" ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:82:suffix or operands invalid for `push' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:83:suffix or operands invalid for `push' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:84:suffix or operands invalid for `push' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:86:suffix or operands invalid for `pop' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:87:Missing operand value assumed absolute 0. ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:87:junk `[.-1b]' after expression ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:90:suffix or operands invalid for `pop' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:91:suffix or operands invalid for `pop' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:92:suffix or operands invalid for `pop' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:101:suffix or operands invalid for `pop' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:112:suffix or operands invalid for `pop' ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:113:Missing operand value assumed absolute 0. ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:113:junk `[.-3b]' after expression ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:116:suffix or operands invalid for `push' darwin.compile.c++ ../../../bin.v2/libs/context/build/darwin-4.2.1/debug/address-model-32/fcontext.o Applying the 64-bit change from Daniel Larimer on 13th May and adding -arch=i386 to the as flags gets things further: as -o "../../../bin.v2/libs/context/build/darwin-4.2.1/debug/address-model-32/architecture-x86/asm/fcontext_i386_sysv_macho_gas.o" "../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S" -arch i386 ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:87:Missing operand value assumed absolute 0. ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:87:junk `[.-1b]' after expression ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:113:Missing operand value assumed absolute 0. ../../../libs/context/src/asm/fcontext_i386_sysv_macho_gas.S:113:junk `[.-3b]' after expression From a quick google, it sounds like _GLOBAL_OFFSET_TABLE is an ELF only thing. I'm now way out of my depth and probably can't really help any further (though happy to try out any fixes). Probably not of much relevance but: sw_vers ProductName: Mac OS X ProductVersion: 10.7.4 BuildVersion: 11E53 as -version Apple Inc version cctools-822, GNU assembler version 1.38 I hope that is of some use! ucontext throws up a deprecated warning so it would be nice to switch to boost.context one day. I've not tried Mountain Lion yet so don't know if they've actually removed ucontext support or if it's still deprecated. Best regards Luke Elliott.

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[1.51][Wave] Last minute commit
by Hartmut Kaiser 07 Aug '12

07 Aug '12

Hey, I would like to ask for permission to commit rev 79783 to the release branch (see attached patch). This fixes a bug introduced only recently and will fix the current regressions (see here: http://tinyurl.com/c44ql68, for instance). The patch is for Wave only and does not touch any of the other Boost libraries. Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[review] Multiprecision review (June 8th - 17th, 2012)
by Jeffrey Lee Hellrung, Jr. 07 Aug '12

07 Aug '12

Okay, it's that time. Apologies for not sending a reminder, but there had been a lot of pre-review comments over the last week or so, so I think this has been on at least some people's radar. The original review announcement is given below. On Tue, May 29, 2012 at 2:08 PM, Jeffrey Lee Hellrung, Jr. < jeffrey.hellrung(a)gmail.com> wrote: > Hi all, > > The review of the proposed Boost.Multiprecision library authored by John > Maddock and Christopher Kormanyos has been scheduled for > > June 8th - June 17th, 2012 > > and will be managed by myself. > > From the Introduction: > > -------- > "The Multiprecision Library provides *User-defined* integer, rational and > floating-point C++ types which try to emulate as closely as practicable the > C++ built-in types, but provide for more range and precision. Depending > upon the number type, precision may be arbitrarily large (limited only by > available memory), fixed at compile time values, for example 50 decimal > digits, or a variable controlled at run-time by member functions. The types > are expression-template-enabled for better performance than naive > user-defined types." > -------- > > And from the original formal review request from John: > > -------- > Features: > > * Expression template enabled front end. > * Support for Integer, Rational and Floating Point types. > > Supported Integer backends: > > * GMP. > * Libtommath. > * cpp_int. > > cpp_int is an all C++ Boost licensed backend, supports both arbitrary > precision types (with Allocator support), and signed and unsigned fixed > precision types (with no memory allocation). > > There are also some integer specific functions - for Miller Rabin testing, > bit fiddling, random numbers. Plus interoperability with Boost.Rational > (though that loses the expression template frontend). > > Supported Rational Backends: > > * GMP > * libtommath > * cpp_int (as above) > > Supported Floating point backends: > > * GMP > * MPFR > * cpp_dec_float > > cpp_dec_float is an all C++ Boost licensed type, adapted from Christopher > Kormanyos' e_float code (published in TOMS last year). > > All the floating point types, have full std lib support (cos sin exp, pow > etc), as well as full interoperability with Boost.Math. > > There's nothing in principal to prevent extension to complex numbers and > interval arithmetic types (plus any other number types I've forgotten!), > but I've run out of energy for now ;-) > > Code is in the sandbox under /big_number/. > > Docs can be viewed online here: > http://svn.boost.org/svn/boost/sandbox/big_number/libs/multiprecision/doc/h… > -------- > Any review discussion should take place on the developers' list ( boost(a)lists.boost.org) and anyone may submit a formal review, either publicly to the entire list or privately to just myself. As usual, please consider the following questions in your formal review: What is your evaluation of the design? What is your evaluation of the implementation? What is your evaluation of the documentation? What is your evaluation of the potential usefulness of the library? Did you try to use the library? With what compiler? Did you have any problems? How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? Are you knowledgeable about the problem domain? And, most importantly, please explicitly answer the following question: Do you think the library should be accepted as a Boost library? Lastly, please consider that John and Christopher have compiled a TODO list [1] based on pre-review comments. Feel free to comment on the priority and necessity of such TODO items, and whether any might be show-stoppers or warrant conditional acceptance of the library. Thanks in advance; looking forward to the discussion! - Jeff (& John & Christopher) [1] http://svn.boost.org/svn/boost/sandbox/big_number/libs/multiprecision/doc/h…

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[type_erasure] Review started (July 18-27, 2012)
by Lorenzo Caminiti 06 Aug '12

06 Aug '12

Hello all, *** The review of Steven Watanabe's proposed Boost.TypeErasure library begins on July 18, 2012 and ends on July 27, 2012. *** THE LIBRARY C++ provides runtime polymorphism through virtual functions. They are a very useful feature, but they do have some limitations. * They are intrusive. In generic programming, we can design an interface which allows third-party types to be adapted to it. * They require dynamic memory management. Of course, most of the problems can be avoided by using an appropriate smart pointer type. Even so, it still acts like a pointer rather than a value. * Virtual functions' ability to apply multiple independent concepts to a single object is limited. The Boost.TypeErasure library solves these problems allowing us to mirror static generic programming at runtime. Library source: http://svn.boost.org/svn/boost/sandbox/type_erasure/ Pre-built documentation: http://steven_watanabe.users.sourceforge.net/type_erasure/libs/type_erasure/ You can also download archives with pre-built documentation from: http://sourceforge.net/projects/steven-watanabe.u/files/ YOUR REVIEW Please submit a review to the mailing-list by replying to this email ("[boost] [type_erasure] Review ..." should be in the subject). Please state clearly whether you think this library should be accepted as a Boost library. Other questions you may want to consider: 1. What is your evaluation of the design? 2. What is your evaluation of the implementation? 3. What is your evaluation of the documentation? 4. What is your evaluation of the potential usefulness of the library? 5. Did you try to use the library? With what compiler? Did you have any problems? 6. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? 7. Are you knowledgeable about the problem domain? Thanks in advance to all who participate in the review discussion -- I'm looking forward to it! The review manager. --Lorenzo

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interest in generic cyclic visitor?
by Jan Herrmann 06 Aug '12

06 Aug '12

Hello, I have an implementation of generic cyclic visitor. It is available at https://github.com/janherrmann/visitor . With my implementation it is possible to create non-member, non-friend templates which behave like virtual functions. Additionally it can be used as a base for multimethod implementation. Moreover it can be used to build a extensible type information system. All test cases compile with msvc-10.0 and gcc-mingw-4.6.2. Is there need for such a library? Jan Herrmann

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[multiprecision] Some Performance gains
by John Maddock 05 Aug '12

05 Aug '12

Following the review of the multiprecision lib, I've been experimenting with some of the issues raised, currently focusing on performance improvements. Anyhow, I now have some results for improved *front end* performance, I haven't tried to seriously optimize the cpp_int backend yet (which was one of the criticisms), but for more on that see below. So... by way of measuring front end performance - the "abstraction penalty" if you like I've used a special backend type "arithmetic_backend<A>" where A can be any builtin arithmetic type. For tests I've used Boost.Math's special function test data for floating point types, and Phil Endecott's Delaunay code for integer performance. Win32 VC10 first: Delaunay test: int64_t : 9.45241 mp_number<arithmetic_backend<int64_t>, false> : 9.66815 Bessel Functions Test: Time for Bessel Functions - double = 0.015859 seconds Time for Bessel Functions - arithmetic_backend<double> - no expression templates = 0.0225565 seconds Time for Bessel Functions - arithmetic_backend<double> = 0.0376449 seconds Non Central T: Time for Non-central T - double = 0.456739 seconds Time for Non-central T - arithmetic_backend<double> - no expression templates = 0.459957 seconds Time for Non-central T - arithmetic_backend<double> = 1.08256 seconds Ubutunu Linux x64, GCC-4.6.1: Delaunay Test: int64_t 2.3969 mp_number<arithmetic_backend<int64_t>, false> 2.38334 Bessel Functions Test: Time for Bessel Functions - double = 0.0224617 seconds Time for Bessel Functions - arithmetic_backend<double> - no expression templates = 0.020384 seconds Time for Bessel Functions - arithmetic_backend<double> = 0.0220476 seconds Non central T: Time for Non-central T - double = 0.622985 seconds Time for Non-central T - arithmetic_backend<double> - no expression templates = 0.554527 seconds Time for Non-central T - arithmetic_backend<double> = 0.800129 seconds So to all intents and purposes there's now no abstraction penalty at all, except when using expression templates (which should be reserved for heavyweight backends anyway). Notice how the mp_number code is sometimes slightly faster, and sometimes slightly slower than the native type - I've observed that completely trivial changes to the test/measuring code can change this around - I suspect, but can't prove that the abstraction layer changes the decisions made by the compiler's optimizer resulting in somewhat capricious differences between results. With regard to the cpp_int backend, I still have work to do, however things do actually look pretty good on Linux x64 for the Delaunay test: Running calculations for: int64_t, int128_t (this is Phil's 128-bit special-case code) Number of flips = 23892000 Total execution time = 3.28337 Running calculations for: int64_t, mp_int128_t Number of flips = 23892000 Total execution time = 3.05434 Running calculations for: int64_t, mp_int128_t (ET) Number of flips = 23892000 Time per calculation = 3.02904e-08 Running calculations for: int64_t, cpp_int Number of flips = 23892000 Total execution time = 5.41737 On Win32, I'm still a touch behind Phil's code, however, I haven't written a dedicated NxN->2N multiplication routine (yet): Running calculations for: int64_t, int128_t Number of flips = 23892000 Total execution time = 14.2189 Running calculations for: int64_t, mp_int128_t Number of flips = 23892000 Total execution time = 24.5114 Running calculations for: int64_t, mp_int128_t (ET) Number of flips = 23892000 Total execution time = 19.741 Running calculations for: int64_t, cpp_int Number of flips = 23892000 Total execution time = 33.5 All the new code is in the sandbox, but I haven't documented any of the changes yet... Regards, John.

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[typeof][implementation]why not use decltype or conditional expr?
by Larry Evans 05 Aug '12

05 Aug '12

Why couldn't the BOOST_TYPEOF macro be defined to simply use the new keyword, decltype, if it's available? I assume the macro, BOOST_HAS_DECLTYPE, indicates whether it is available. And if decltype not available, why couldn't it use the conditional expression method described here: http://www.artima.com/cppsource/foreach2.html I would think that would be simpler and more portable. -regards Larry

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