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Review Wizard Status Report for July 2012
by Ronald Garcia 13 Jul '12

13 Jul '12

============================================== Review Wizard Status Report for July 2012 ============================================== News ==== 1. Multiprecision Arithmetic Reviewed 2. Boost 1.50.0 Released. New Libraries: 1) Algorithm 2) Functional/OverloadedFunction 3) LocalFunction 4) Utility/IdentityType Open Issues =========== The following libraries have been reviewed and await reports from their review managers: * Conversion - reviewed August 2011; review manager: Gordon Woodhull. * Predef - reviewed February 2012; review manager: Joel Falcou. * Multiprecision - reviewed June 2012; review manager: Jeffrey Hellrung The following libraries have been accepted to Boost, but have not yet been submitted to SVN: * Constrained Value - accepted September 2010; author: Robert Kawulak. * GIL.IO - accepted January 2011; author: Christian Henning. The following libraries have been accepted and submitted to SVN, but have not yet appeared in a release: * Atomic - accepted July 2011; author Helge Bahmann. * Type Traits Introspection - accepted August 2011; author: Edward Diener. * Lockfree - accepted August 2011; author: Tim Blechmann. * Context - accepted January 2012; author: Oliver Kowalke. The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * Endian - accepted provisionally November 2011; author: Beman Dawes. * Log - accepted provisionally March 2010; author: Andrey Semashev. General Announcements ===================== As always, we need experienced review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "rxg at cs dot cmu dot edu" and "phillips at pacific dot mps dot ohio-state dot edu" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report before we do that, please email Ron or John. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Review Schedule =============== * Join (M) * Pimpl (M) * Sorting (M) * Quaternions, Vectors, Matrices (M) * Variadic Macro Data (M) * Block Pointer (M) * Singularity (M) * Extended Complex Numbers (M) * Metaparse (M) * Polygon: Voronoi Extensions * Coroutine * Type Erasure * Range Extensions * Contract * Nowide (M) * ODEint (M) ``(M)`` marks libraries that need review managers. -------------------- Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Pimpl ----- :Author: Vladimir Batov :Review Manager: Needed :Download: https://github.com/boost-vault/Miscellaneous/blob/master/Pimpl.zip :Description: The Pimpl idiom is a simple yet robust technique to minimize coupling via the separation of interface and implementation and then implementation hiding. This library provides a convenient yet flexible and generic deployment technique for the Pimpl idiom. It's seemingly complete and broadly applicable, yet minimal, simple and pleasant to use. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: https://github.com/boost-vault/Sorting :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 2X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 70% faster than std::sort. string_sort is roughly 2X as fast as std::sort. Quaternions, Vectors, Matrices ------------------------------ :Author: Emil Dotchevski :Review Manager: Needed :Download: http://www.revergestudios.com/boost-qvm/ :Description: QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Variadic Macro Data ------------------- :Author: Edward Diener :Review Manager: Needed :Download: `Boost Sandbox <http://svn.boost.org/svn/boost/sandbox/variadic_macro_data/>`__ :Description: This library adds support and functionality for variadic macros to Boost as well as integrating variadic macros with the Boost PP library without changing the latter library in any way. Block Pointer ------------- :Author: Phil Bouchard :Review Manager: Needed :Download: https://svn.boost.org/svn/boost/sandbox/block_ptr/ :Description: Deterministic memory manager of constant complexity capable of handling cyclic collections. Singularity ----------- :Author: Ben Robinson :Review Manager: Needed :Download: https://github.com/cppmaven/Singularity :Description: The Singularity Design Pattern allows you to restrict any class to a single instance. Unlike the infamous Singleton, Singularity gives you direct control over the lifetime of the object, does not require you to grant global access to the object, nor does it limit you to the default constructor for that object. Extended Complex Numbers ------------------------ :Author: Matthieu Schaller :Review Manager: Needed :Download: http://code.google.com/p/cpp-imaginary-numbers/ :Description: The library is an extension of the std::complex class addressing two issues: 1. The standard does not guaranty the behaviour of the complex class if instantiated with types other than float/double/long double. 2. Some calculation where pure imaginary numbers (i.e. multiples of sqrt(-1)) appear are unnecessarily slowed down due to the lack of support for these numbers. The code I submit contains two interleaved classes boost::complex and boost::imaginary which can be instantiated with any type T provided T overloads the usual arithmetic operators and some basic (real) mathematical functions depending on which complex function will be used. It is thus an extended version of Thorsten Ottosen's n1869 proposal (http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1869.html) Metaparse --------- :Author: Abel Sinkovics :Review Manager: Needed :Download: http://abel.web.elte.hu/metaparse/metaparse.zip :Description: Metaparse is a library for constructing parsers parsing at compile-time based on template metaprogramming. The parsers built with the library take boost::mpl::strings as input and can produce - types - objects (types with public static members) - callable C++ functions (types with public static method) - template metafunction classes as output (based on the input being parsed). On compilers supporting constexpr the library provides the following syntactic sugar for writing the input of the parsers: BOOST_STRING("this is a string") The library can be used for implementing DSLs in C++, including DSLs making C++ template metaprogramming easier (see examples). Polygon: Voronoi Extensions --------------------------- :Author: Andril Sydorchuk :Review Manager: Lucanus Simonson :Download: http://svn.boost.org/svn/boost/sandbox/gtl/ :Description: This library extends Boost.Polygon with the following features: - Robust and efficient implementation of the sweepline algorithm that allows to construct Voronoi diagram, Delaunay triangulation and medial axis of a set of points and line segments. - Coordinates of the output geometries are computed within the 64 machine epsilon relative error (6 mantissa bits). - Voronoi diagram data structure that allows efficient traversal and data association with the output Voronoi graph. - No 3rd party dependencies (e.g. GMP, MPFR), all the required multiple precision types are implemented as part of the library. - The input and output coordinate type domains are configurable via coordinate type traits, thus allowing to compute coordinates of the Voronoi vertices within any required precision. - The full construction of the Voronoi diagram of 100 000 points takes only 0.27 seconds (see benchmarks). Coroutine --------- :Author: Oliver Kowalke :Review Manager: Hartmut Kaiser :Download: http://gitorious.org/boost-dev/boost-dev/archive-tarball/coroutine :Description: This library is an implementation of coroutines and generators using Boost.Context. Type Erasure ------------ :Author: Steven Watanabe :Review Manager: Lorenzo Caminiti :Download: http://sourceforge.net/projects/steven-watanabe.u/files/ :Description: The TypeErasure library is a generalization of boost::any and boost::function. It allows easy composition of arbitrary type erased operators. Range Extensions ---------------- :Author: Akira Takahashi :Review Manager: Neil Groves :Download: https://github.com/faithandbrave/OvenToBoost :Description: This project adds some features of the Oven Range Library to Boost.Range. Features: - Additional Range Adaptors (taken, taken_while, dropped, dropped_while, elements, elements_key, memoized, outdirected) - Extensions for using Lambda (regular function, regular operator) - Infinite Range (iteration function) - and additional range utilities. Contract -------- :Author: Lorenzo Caminiti :Review Manager: Dave Abrahams :Download: http://sourceforge.net/projects/contractpp/files/latest/download :Description: This library implements Contract Programming for the C++ programming language (see the end of this email). In addition, the library implements virtual specifiers (final, override, and new, see C++11), concept checking, and named parameters. This library is implemented for the C++03 standard and it does not require C++11. Nowide ------ :Author: Artyom Beilis :Review Manager: Needed :Download: http://cppcms.com/files/nowide/ :Description: This library makes cross platform Unicode aware programming easier. It provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. ODEint ------ :Author: Karsten Ahnert and Mario Mulansky :Review Manager: Needed :Download: https://github.com/headmyshoulder/odeint-v2 :Description: odeint provides routines for numerically solving Ordinary Differential Equations, a task heavily required when approaching scientific problems numerically. In odeint we have implemented the most common algorithms in a modern, generic way which provides several advantages over existing implementations. The main focus of odeint is to separate algorithms from the underlying basic computation unit. This allows for example to easily use the power of modern GPUs via CUDA or OpenCL to speed up computational heavy simulations. Libraries under development =========================== See http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction for a current listing of libraries under development.

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eos_portable_archive for 1.49
by Paul Harris 13 Jul '12

13 Jul '12

Hi all, Does anyone know if eos_portable_archive is still actively used and maintained? It doesn't compile with boost 1.49, and before I try to fix it up, I was wondering if anyone else has fixed it up. cheers Paul

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[1.48] interprocess consumes 100% on 32bit Windows systems
by Bogdan Slusarczyk 13 Jul '12

13 Jul '12

Hi All, I found such problem: N+1 (where N is number of cpu cores) processes with interprocess syncing use 100% cpu on 32 bit Windows system. Cause of bug: https://svn.boost.org/trac/boost/changeset/74110 void sched_yield() -{ Sleep(1); } +{ + if(!SwitchToThread()){ + Sleep(1); + } Test case: #include <windows.h> #include <iostream> int main() { int i = 0; while( true ) { if ( !SwitchToThread() ) { std::cout << "sleep" << i++ << std::endl; Sleep(1); } } } On 32 bit windows system running this in N+1 separate processes will stop printing and use 100% CPU. On 64 bit system for any number of processes printing will not stop. Kind regards, Bogdan

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const native arrays at compile time
by Hicham Mouline 12 Jul '12

12 Jul '12

Hello, I have a number of questions, some of which are boost specific. 1. const std::string cols[] = { "col1", "col2", "col3" }; Is the const native array cols completely a compile-time construct or are std::string objects constructed at runtime? I would guess the latter? 2. const char const* cols[] = { "col1", "col2", "col3" }; This on the other hand would be pure compile time? 3. struct S1 { const char const* cols[] = { "col1", "col2", "col3" }; }; struct S2 { const char const* cols[] = { "colx", "coly", "coly" }; }; template <typename T> /// T is either S1 or S2 struct S { const char const* col1s[] = { "othercol", /// elements of T::cols }; }; Is there a way to build col1s at compile time? MM

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boost any_range
by tolik levchik 12 Jul '12

12 Jul '12

Is it possible the commented below condition. With regular ranges i make as many 'base()' calls as may adaptors i had applied. Obviously it's impossible with any_range. So what should i do ? #include <map> #define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 0 #include <boost/range/adaptors.hpp> #include <boost/range/algorithm.hpp> #include <boost/range/numeric.hpp> #include <boost/bind.hpp> #include <boost/range/any_range.hpp> struct foo{ int x, y; }; inline bool is_valid(int x){ return x > 0;} int main() { using namespace boost::adaptors; using boost::bind; typedef std::map<char, foo> map_t; typedef const int type; typedef boost::any_range< type, boost::forward_traversal_tag, typename boost::add_reference<type>::type, std::ptrdiff_t > forward_range_t; map_t m; forward_range_t rng = m | map_values | transformed(bind(&foo::x, _1)); // note: don't compile without BOOST_RANGE_ENABLE_CONCEPT_ASSERT defined as 0 forward_range_t::const_iterator found = boost::find_if(rng, is_valid); // found == boost::end(m); how to do it right ? }

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serialization with templates
by Unger, Jörg F. 12 Jul '12

12 Jul '12

I'm trying to serialize a template class with multiple template parameters. In the header file, I declare something like template <int T1, int T2> class Node { private: std::array<double,T1> first; std::array<double,T2> second; } BOOST_CLASS_EXPORT_KEY(Node<1,1>) In a separate file, I would use the BOOST_CLASS_EXPORT_IMPLEMENT macro. However, when I'm using the BOOST_CLASS_EXPORT_KEY with a class that has more than one template parameter (as in the example above), I get an error message Error: macro "BOOST_CLASS_EXPORT_KEY" passed 2 arguments, but takes just 1 I'm using gcc 4.7.1 with boost 50 Any ideas, how to solve that problem? Jörg F.

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Is there any interest in getting pseudo random number generation using preprocessor at compile time into the Preprocessor library?
by Alexander Stoyan 12 Jul '12

12 Jul '12

The complete code, approach and efficiency proofs I described in my blog: http://alexander-stoyan.blogspot.com/2012/07/getting-pseudo-random-numbers-a t.html Need your opinion regarding the relevance and the approach correctness of the feature. Thank you in advance.

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[StateChart] Accessing machine and state members from within state constructor
by Andre Puschmann 12 Jul '12

12 Jul '12

Hello, I'd like to outsource some common functionality into a base state which needs to access some member variables from the state machine or from its direct context. I've managed to do exactly this in the constructor of the inherited class but not inside the constructor of the base class. I believe I am missing some bits here. Thanks in advance -Andre Code: #include <boost/statechart/event.hpp> #include <boost/statechart/state_machine.hpp> #include <boost/statechart/state.hpp> #include <boost/statechart/simple_state.hpp> #include <boost/statechart/transition.hpp> #include <boost/statechart/custom_reaction.hpp> #include <iostream> namespace sc = boost::statechart; // event definition struct EvReset : sc::event< EvReset > {}; // forward definition struct Active; // starting state struct State1; // define FSM struct TestFsm : sc::state_machine< TestFsm, Active > { TestFsm() { std::cout << "Start TestFsm.\n"; fsmValue = 0; std::cout << "value: " << fsmValue << std::endl; } ~TestFsm() { std::cout << "Shut down TestFsm.\n"; } public: int fsmValue; }; struct Active : sc::state< Active, TestFsm, State1 > { Active(my_context ctx) : my_base( ctx ) { std::cout << "Start Active state!\n"; outermost_context().fsmValue++; stateValue = 0; std::cout << "value: " << outermost_context().fsmValue << std::endl; } ~Active() { std::cout << "Leave and desctruct Active state!\n"; } public: int stateValue; typedef sc::transition< EvReset, Active > reactions; }; template< class MostDerived, class Context > struct StateBase : sc::state< MostDerived, Context> { typedef sc::state< MostDerived, Context> base_type; typedef typename base_type::my_context my_context; typedef StateBase my_base; StateBase( my_context ctx ) : base_type( ctx ) { std::cout << "StateBase cst" << std::endl; // critical section outermost_context().fsmValue++; // access member of FSM (outermost context) ctx().stateValue++; // access member in direct context } }; struct State1 : StateBase< State1, Active > { State1(my_context ctx) : my_base( ctx ) { std::cout << "State1 cst" << std::endl; outermost_context().fsmValue++; std::cout << "value: " << outermost_context().fsmValue << std::endl; }; ~State1() {}; }; int main() { TestFsm myFSM; myFSM.initiate(); return 0; }

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compilation problem and a couple of boost::variant questions
by Petros 12 Jul '12

12 Jul '12

Hi, I am trying to write some operator that multiplies two variants, each one containing a vector a zero and a unit, where I am trying to use the fact that I know the outcome for multiplying by 0 or by 1. The code (very bare bones) below describes how this is done, by: _ defining dummy structures of Variant-1, 2 _ defining a class that contains the instruction for multiplication _ defining a class (derived from variant) that contains possible outcomes of the multiplication _ defining the operator (only a few of the possible outcomes are shown) Compiling with msvc2010 (intel has similar issues) on win7: First here is the code: #include <boost/variant.hpp> using boost::variant; struct Zero1{ double operator[]( const size_t i ) const { return 0L ; } }; struct One1{ double operator[]( const size_t i ) const { return 1L ; } }; struct Zero2{ double operator[]( const size_t i ) const { return 0L ; } }; struct One2{ double operator[]( const size_t i ) const { return 1L ; } }; struct Vector1{ double operator[]( const size_t i ) const {return double( i ) ; } }; struct Vector2{ double operator[]( const size_t i ) const {return double( 2*i ) ; } }; struct subscript_operator:public boost::static_visitor<double>{ const size_t i_; subscript_operator( const size_t i ):i_(i){} template<typename _v> double operator()( _v const & v ) const { return v[i] ; } }; template <typename _V, typename _Z, typename _U> class VariantT :public variant< _V, _Z, _U > { public: typedef typename _Z zero_type ; typedef typename _U unit_type ; typedef typename VariantT<_V, _Z, _U> self_type ; typedef typename variant< _V, _Z, _U > variant_type ; template < typename _V> explicit VariantT( _V const & v ) :variant_type(v) {} VariantT() {} VariantT( self_type const & v ) :variant_type(static_cast<const variant_type&>(v)) {} template < typename _V> VariantT & operator = ( _V const & v ) { *static_cast<variant_type*>(this) = static_cast<const variant_type&>(v); return(*this); } VariantT & operator = ( self_type const & v ) { *static_cast<variant_type*>(this) = v; return(*this); } double operator[]( const size_t i ) const { boost::apply_visitor( subscript_operator(i) , *this ) ; } bool isZero() const { return which() == 1 ; } bool isUnit() const { return which() == 2 ; } private: }; template < typename _V1, typename _V2 > class MultVarVar{ public: MultVarVar( _V1 const & v1, _V2 const & v2 ) :v1_(v1),v2_(v2) {} ~MultVarVar() {} typedef typename _V1::zero_type zero_type ; typedef typename _V1::unit_type unit_type ; double operator[]( const size_t i ) const { return boost::apply_visitor ( elementwise_visitor( i ), v1, v2 ) ; } private: _V1 const & v1_ ; _V2 const & v2_ ; struct elementwise_visitor : public boost::static_visitor< double > { const size_t & i_; public: elementwise_visitor( const size_t & i ) :i_(i) {} template <typename _V1, typename _V2 > double operator()( _V1 const & v1, _V2 const & v2) const { return v1[i_] * v2[i_] ; } }; }; template < typename _V1, typename _V2 > class MultVarVarResult :public variant<typename MultVarVar<_V1, _V2>, typename MultVarVar<_V1,_V2>::zero_type, typename MultVarVar<_V1,_V2>::unit_type, _V1, _V2 > { public: typedef typename variant< typename MultVarVar<_V1, _V2 > , typename MultVarVar<_V1,_V2>::zero_type, typename MultVarVar<_V1,_V2>::unit_type, _V1, _V2 > variant_type; typedef typename MultVarVarResult<_V1, _V2> self_type ; typedef typename _V1::zero_type zero_type ; typedef typename _V1::unit_type unit_type ; template<typename _V> /*explicit*/ MultVarVarResult( _V const & v ) :variant_type(v) {} MultVarVarResult( self_type const & v ) :variant_type(static_cast<const variant_type&>(v)) {} template < typename _V> MultVarVarResult & operator = ( _V const & v ) { *static_cast<variant_type*>(this) = static_cast<const variant_type&>(v); return(*this); } MultVarVarResult & operator = ( self_type const & v ) { *static_cast<variant_type*>(this) = v; return(*this); } double operator[]( const size_t i ) const { boost::apply_visitor( subscript_operator(i), *this ) ; } private: }; template <typename _V1, typename _V2> MultVarVarResult<_V1, _V2> operator * ( _V1 const & v1, _V2 const & v2 ) { if ( v1.isZero() || v2.isZero() ) return MultVarVarResult<_V1, _V2>( typename MultVarVar<_V1,_V2>::zero_type() ) ; if ( v1.isUnit() ) return MultVarVarResult<_V1, _V2>( v2 ); if ( v2.isUnit() ) return v1 ; else return MultVarVarResult<_V1, _V2>( MultVarVar<_V1, _V2>( v1, v2 ) ) ; } typedef VariantT< Vector1, Zero1, One1 > Variant1; typedef VariantT< Vector2, Zero2, One2 > Variant2; int main(){ Variant1 v1; v1 = Zero1() ; Variant2 v2; v2 = One2() ; auto x = v1 * v2 ; return x[0] == double(0) ; } And here is one of the errors : boost_1_49_0\boost\variant\variant.hpp(1399): error C2666: 'boost::variant<T0_,T1,T2,T3,T4>::convert_construct' : 2 overloads have similar conversions 1> with 1> [ 1> T0_=MultVarVar<Variant1,Variant2>, 1> T1=Zero1, 1> T2=One1, 1> T3=Variant1, 1> T4=Variant2 1> ] 1> c:\_petros\_otc\ext\boost_1_49_0\boost\variant\variant.hpp(1384): could be 'void boost::variant<T0_,T1,T2,T3,T4>::convert_construct<_V,_Z,_U,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_,boost::detail::variant::void_>(const boost::variant<_V,T1,T2> &,long)' 1> with 1> [ 1> T0_=MultVarVar<Variant1,Variant2>, 1> T1=Zero1, 1> T2=One1, 1> T3=Variant1, 1> T4=Variant2, 1> _V=Vector1, 1> _Z=Zero1, 1> _U=One1 1> ] 1> c:\_petros\_otc\ext\boost_1_49_0\boost\variant\variant.hpp(1315): or 'void boost::variant<T0_,T1,T2,T3,T4>::convert_construct<const T>(T &,int,boost::mpl::false_)' 1> with 1> [ 1> T0_=MultVarVar<Variant1,Variant2>, 1> T1=Zero1, 1> T2=One1, 1> T3=Variant1, 1> T4=Variant2, 1> T=Variant1 1> ] 1> while trying to match the argument list '(const Variant1, long)' 1> c:\_petros\_otc\tests\variant\variant\main.cpp(120) : see reference to function template instantiation 'boost::variant<T0_,T1,T2,T3,T4>::variant<_V>(const T &)' being compiled 1> with 1> [ 1> T0_=MultVarVar<Variant1,Variant2>, 1> T1=Zero1, 1> T2=One1, 1> T3=Variant1, 1> T4=Variant2, 1> _V=Variant1, 1> T=Variant1 1> ] 1> c:\_petros\_otc\tests\variant\variant\main.cpp(151) : see reference to function template instantiation 'MultVarVarResult<_V1,_V2>::MultVarVarResult<_V1>(const _V &)' being compiled 1> with 1> [ 1> _V1=Variant1, 1> _V2=Variant2, 1> _V=Variant1 1> ] 1> Any help on this will be greatly appreciated! And the questions: What happens if a variant contains two identical template arguments ? when I create a (variant) object from one of the two identicals, how does it know which template argument I need ? Do I have to write the same code for the specialization of identical _V1 and _V2? Also, am I correct to assume that all this syntax ( element-wise static_visitor’s etc) will be optimized away at a release build ? TVMIA Petros

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Boost 1.49 Locale Conversion failed
by NtVisigoth 12 Jul '12

12 Jul '12

Hello, everyone! I have already answred here: http://lists.boost.org/boost-users/2012/07/75097.php But previous latter badly typed. When using boost::locale with the russian language of the string in UTF-8 encoding I get an error while getting the locale. An exception with the message e.what(): "Conversion failed" is thrown My code is not very different from that in the examples: #define TR(S) boost::locale::translate(S).str() const std::string strDefaultLangId( "en" ); int main( int argc, char * argv[] ) { using namespace std; using namespace boost::locale; int exitCode = EXIT_SUCCESS; try { generator gen; gen.add_messages_path("g:\\source\\boost_locale\\languages\\"); gen.add_messages_domain("messages"); std::string language( argc == 2 ? argv[1] : strDefaultLangId.c_str() ); std::locale loc = gen( language ); locale::global( loc ); std::wstring s = TR(L"hello world"); wcout << s << endl; } catch( exception& e ) { cout << "Error : " << e.what() << endl; exitCode = EXIT_FAILURE; } catch( ... ) { cout << "Unknown error" << endl; exitCode = EXIT_FAILURE; } return exitCode; } The path to the file with the russian language: "g:\source\boost_locale\languages\ru\LC_MESSAGES\messages.mo" What could be wrong? * Is it necessary to use the backends? * Is it yet necessary to call imbue on the stream? But I'd like avoid it because I am going to write the log using glog. Compillers : Microsoft Visual Studio 2008 and 2010 Boost version : 1.49

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