March 2008 - Boost-users - lists.boost.org

[Review] Proto review starts today, March 1st
by Hartmut Kaiser 01 Mar '08

01 Mar '08

Hi all, The review of Eric Nieblers Proto library starts today, March 1st 2008, and will end on March 14th. I really hope to see your vote and your participation in the discussions on the Boost mailing lists! --------------------------------------------------- About the library: Proto is a framework for building Domain Specific Embedded Languages in C++. It provides tools for constructing, type-checking, transforming and executing expression templates. More specifically, Proto provides: * An expression tree data structure. * Operator overloads for building the tree from an expression. * Utilities for defining the grammar to which an expression must conform. * An extensible mechanism for immediately executing an expression template. * An extensible set of tree transformations to apply to expression trees. * A mechanism for giving expressions additional behaviors and members. Documentation is here: http://boost-sandbox.sourceforge.net/libs/proto Download proto.zip from here: http://www.boost-consulting.com/vault/index.php?directory=Template%20Metapro gramming Proto is a very important infrastructure library, IHMO. It has been used as the backbone for several other library writing efforts already, such as Xpressive and the rewrite of Spirit (there it has been used for all three parts: the parser, the lexer and the generator modules), and it is a key enabling technology in the long-planned unification of Phoenix and the Lambda Library. --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - 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? Regards Hartmut Review Manager

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templates: parts of functions
by Hicham Mouline 01 Mar '08

01 Mar '08

Hi, I have a function makeTree whose behavior depends on 3 different policies typename T1 typename T2 int N For performance reasons, I need to write the 2- and 3- specializations alongside the general N case. That is, the 2- and 3- default instantiations generated from the N case by the compiler are not optimal. As it is impossible to write function templates partial specializations, I encapsulate the template< typename T1, typename T2, int N> void makeTree(Head<N>&, const T2&, const C&) ; function in a class template template< typename T1, typename T2, int N> class makeTree{ void makeTree(Head<N>&, const T2&, const C&); }; and write the partial specializations <T1,T2,2> and <T1,T2,3>. Now, this makeTree function is quite large. It includes code that : . doesn't depend on any of the template arguments . code that depends only T1 . code that depends only on T2 . code that depends only on N . code that depends only on <T1,N>. I am worried about code bloat, and the effect on overall performance of the actual code generated even if it is not run (I noticed substantial effects depending on the size of object files and final shared library generated). Besides this, I suppose it is a better design to have these segments of code put in template functions with the right template arguments. Is it MPL the library that I should look into for such work? Perhaps nothing in Boost particularly facilitates this work, and std c++ templates are enough, Thoughts, comments are appreciated, Rds,

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static assert
by Hicham Mouline 29 Feb '08

29 Feb '08

hi, I would like to avoid template instantiations with ContractType whose static functions st1 and st2 return an enum... template <typename ContractType> class C { BOOST_STATIC_ASSERT( !(ContractType::st1()==A && ContractType::st2()==P) ); ... }; Is there a way to make this work?

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Re: [Boost-users] A request for help using the Boost Unit Test Library
by Tim Allison 29 Feb '08

29 Feb '08

> > Tim Allison <tallison <at> meicompany.com> writes: > >> I ran the -E option on the Gnu compiler. Here is what I hope is the >> relevant output (at the end of the 38K resulting file!): > > [...] > >> # 20 "/usr/include/boost/test/unit_test.hpp" 2 3 4 > > [...] > >> BOOST_AUTO_TEST_CASE( test1 ) > > Looks like this is Boost 1.33. You need 1.34 to build examples in new docs. > > Gennadiy > > Where do I find examples for Boost 1.33? Based on your previous remarks, I used: http://www.boost.org/libs/test/example/unit_test_example_01.cpp It is copyrighted 2005. Tim Allison

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