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Review Wizard Status Report for August 2012
by Ronald Garcia 15 Aug '12

15 Aug '12

============================================== Review Wizard Status Report for August 2012 ============================================== News ==== 1. Multiprecision Arithmetic Reviewed 2. Type Erasure Reviewed 3. 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: * 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, 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 * Range Extensions * Contract * Nowide (M) * ODEint * Array (M) * TypeIndex (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. 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: Steven Watanabe :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. Array ----- :Author: Brian Smith :Review Manager: Needed :Download: https://github.com/BrianJSmith/Array :Description: The array class is a C++11 compatible implementation of static multidimensional arrays. TypeIndex --------- :Author: Antony Polukhin :Review Manager: Needed :Download: https://github.com/apolukhin/type_index :Description: TypeIndex is an extended C++11 type_index library, that * works with disabled RTTI * can store const-volatile-reference info about types (if user requested it) * has all the functionality of std::type_index * has portable across compilers and platforms functionality for getting demangled type names * works across modules/shared libraries * does not require C++11 to work Libraries under development =========================== See http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction for a current listing of libraries under development.

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Is unit test framework still not thread-safe?
by Chris Cleeland 15 Aug '12

15 Aug '12

I just want to verify...is Boost's unit test framework still not thread-safe? FWIW, I'm using 1.47.0. -- Chris Cleeland

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Move semantics for sparse matrix classes ?
by Rishi Amrit 15 Aug '12

15 Aug '12

Hi, I wanted to check if move constructors have been added to the sparse matrix classes yet ? Thanks, Kind regards, R.

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[Building Boost] Is there a way to customize dll names?
by Rob Conde 14 Aug '12

14 Aug '12

I would like to change the default dll names generated by bjam. For example: something_boost_date_time-vc90-mt-1_44.dll rather than: boost_date_time-vc90-mt-1_44.dll Is there a straightforward way of accomplishing this? Thanks in Advance, Rob Conde

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How to connect to any boost::signal with a void returning function?
by Sak 14 Aug '12

14 Aug '12

Hi All, I'm trying to connect a simple void returning function to multiple signals of varying signature, I can see some references mentioning that it's possible using boost::lambda::bind and boost::spirit::bind, But I keep getting compilation errors, Is there something wrong with the following code? Or is there a better way to do it? or is it not possible to do? Boost version: Release 1.46.1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 #include <boost/signals2.hpp>#include <boost/lambda/bind.hpp>#include <boost/lambda/lambda.hpp> #include <boost/spirit/include/phoenix.hpp> using namespace boost::signals2; void func() { printf("Func called!"); } main() { signal<int(int)> sig; sig.connect( (boost::lambda::bind(func), 1) ); // Compilation error // sig.connect( (boost::phoenix::bind(func), 1) ); // Compilation error } I'm getting the following compilation errors when using boost::lambda::bind: 1 2 3 4 5 /opt/include/boost/signals2/detail/slot_template.hpp: In member function ‘void boost::signals2::slot1<R, T1, SlotFunction>::init_slot_function(const F&) [with F = int, R = int, T1 = int, SlotFunction = boost::function<int(int)>]’: /opt/include/boost/signals2/detail/slot_template.hpp:81:9: instantiated from ‘boost::signals2::slot1<R, T1, SlotFunction>::slot1(const F&) [with F = int, R = int, T1 = int, SlotFunction = boost::function<int(int)>]’ hello-world-example.cpp:15:51: instantiated from here /opt/include/boost/signals2/detail/slot_template.hpp:156:9: error: invalid conversion from ‘int’ to ‘boost::function<int(int)>::clear_type*’ [-fpermissive] /opt/include/boost/function/function_template.hpp:1110:14: error: initializing argument 1 of ‘boost::function<R(T0)>::self_type& boost::function<R(T0)>::operator=(boost::function<R(T0)>::clear_type*) [with R = int, T0 = int, boost::function<R(T0)>::self_type = boost::function<int(int)>]’ [-fpermissive] I'm getting the following compilation errors when using boost::phoenix::bind: 1 2 3 4 5 /opt/include/boost/function/function_template.hpp: In static member function ‘static R boost::detail::function::function_obj_invoker1<FunctionObj, R, T0>::invoke(boost::detail::function::function_buffer&, T0) [with FunctionObj = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<0>, boost::fusion::vector<boost::phoenix::value<boost::phoenix::detail::function_ptr<0, void, void (*)()> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, R = int, T0 = int]’: /opt/include/boost/function/function_template.hpp:913:60: instantiated from ‘void boost::function1<R, T1>::assign_to(Functor) [with Functor = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<0>, boost::fusion::vector<boost::phoenix::value<boost::phoenix::detail::function_ptr<0, void, void (*)()> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, R = int, T0 = int]’ /opt/include/boost/function/function_template.hpp:722:7: instantiated from ‘boost::function1<R, T1>::function1(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<0>, boost::fusion::vector<boost::phoenix::value<boost::phoenix::detail::function_ptr<0, void, void (*)()> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, R = int, T0 = int, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ /opt/include/boost/function/function_template.hpp:1064:16: instantiated from ‘boost::function<R(T0)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<0>, boost::fusion::vector<boost::phoenix::value<boost::phoenix::detail::function_ptr<0, void, void (*)()> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, R = int, T0 = int, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ /opt/include/boost/function/function_template.hpp:1105:5: instantiated from ‘typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, boost::function<R(T0)>&>::type boost::function<R(T0)>::operator=(Functor) [with Functor = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<0>, boost::fusion::vector<boost::phoenix::value<boost::phoenix::detail::function_ptr<0, void, void (*)()> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, R = int, T0 = int, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, boost::function<R(T0)>&>::type = boost::function<int(int)>&]’ /opt/include/boost/signals2/detail/slot_template.hpp:156:9: instantiated from ‘void boost::signals2::slot1<R, T1, SlotFunction>::init_slot_function(const F&) [with F = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<0>, boost::fusion::vector<boost::phoenix::value<boost::phoenix::detail::function_ptr<0, void, void (*)()> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, R = int, T1 = int, SlotFunction = boost::function<int(int)>]’ /opt/include/boost/signals2/detail/slot_template.hpp:81:9: instantiated from ‘boost::signals2::slot1<R, T1, SlotFunction>::slot1(const F&) [with F = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::detail::function_eval<0>, boost::fusion::vector<boost::phoenix::value<boost::phoenix::detail::function_ptr<0, void, void (*)()> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, R = int, T1 = int, SlotFunction = boost::function<int(int)>]’ ../../../examples/hello-world/hello-world-example.cpp:16:51: instantiated from here /opt/include/boost/function/function_template.hpp:132:42: error: void value not ignored as it ought to be /opt/include/boost/function/function_template.hpp:133:9: error: control reaches end of non-void function [-Werror=return-type] Many thanks, Sak

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[bind, function] pointer to member function under Xcode 4.1.1
by Stuart Malone 13 Aug '12

13 Aug '12

I'm having trouble compiling some very simple boost::function and boost::bind code under Xcode 4.4.1 using the default Apple LLVM compiler 4.0. I've simplified the code down to: #include <boost/bind.hpp> #include <boost/function.hpp> struct Monitor { void Change(int a, int b); void Lose() { auto b = boost::bind(&Monitor::Change, this); boost::function<void (int, int)> f(b); } }; On the second line of the Lose() function I get the error "reference to non-static member function must be called". The full error message is below. I haven't been able to figure out just where the problem is. Is this an incompatibility between Boost 1.50 and Xcode 4.4.1, or am I making some other mistake? Is there a straightforward workaround? Thanks, —Stuart In file included from /Users/samalone/Projects/functionbind/functionbind/main.cpp:1: In file included from /Users/samalone/Boost/boost/bind.hpp:22: In file included from /Users/samalone/Boost/boost/bind/bind.hpp:26: In file included from /Users/samalone/Boost/boost/mem_fn.hpp:22: /Users/samalone/Boost/boost/bind/mem_fn.hpp:342:16: error: reference to non-static member function must be called return (p->*f_); ^~~~~~~~ /Users/samalone/Boost/boost/bind/bind.hpp:243:16: note: in instantiation of member function 'boost::_mfi::dm<void (int, int), Monitor>::operator()' requested here return unwrapper<F>::unwrap(f, 0)(a[base_type::a1_]); ^ /Users/samalone/Boost/boost/bind/bind_template.hpp:61:27: note: in instantiation of function template specialization 'boost::_bi::list1<boost::_bi::value<Monitor *> >::operator()<void (&)(int, int), boost::_mfi::dm<void (int, int), Monitor>, boost::_bi::list2<int &, int &> >' requested here BOOST_BIND_RETURN l_(type<result_type>(), f_, a, 0); ^ /Users/samalone/Boost/boost/function/function_template.hpp:153:33: note: in instantiation of function template specialization 'boost::_bi::bind_t<void (&)(int, int), boost::_mfi::dm<void (int, int), Monitor>, boost::_bi::list1<boost::_bi::value<Monitor *>> >::operator()<int, int>' requested here BOOST_FUNCTION_RETURN((*f)(BOOST_FUNCTION_ARGS)); ^ /Users/samalone/Boost/boost/function/function_template.hpp:75:36: note: expanded from macro 'BOOST_FUNCTION_RETURN' # define BOOST_FUNCTION_RETURN(X) X ^ /Users/samalone/Boost/boost/function/function_template.hpp:907:53: note: in instantiation of member function 'boost::detail::function::void_function_obj_invoker2<boost::_bi::bind_t<void (&)(int, int), boost::_mfi::dm<void (int, int), Monitor>, boost::_bi::list1<boost::_bi::value<Monitor *>>>, void, int, int>::invoke' requested here { { &manager_type::manage }, &invoker_type::invoke }; ^ /Users/samalone/Boost/boost/function/function_template.hpp:722:13: note: in instantiation of function template specialization 'boost::function2<void, int, int>::assign_to<boost::_bi::bind_t<void (&)(int, int), boost::_mfi::dm<void (int, int), Monitor>, boost::_bi::list1<boost::_bi::value<Monitor *>>> >' requested here this->assign_to(f); ^ /Users/samalone/Boost/boost/function/function_template.hpp:1042:5: note: in instantiation of function template specialization 'boost::function2<void, int, int>::function2<boost::_bi::bind_t<void (&)(int, int), boost::_mfi::dm<void (int, int), Monitor>, boost::_bi::list1<boost::_bi::value<Monitor *>>> >' requested here base_type(f) ^ /Users/samalone/Projects/functionbind/functionbind/main.cpp:9:42: note: in instantiation of function template specialization 'boost::function<void (int, int)>::function<boost::_bi::bind_t<void (&)(int, int), boost::_mfi::dm<void (int, int), Monitor>, boost::_bi::list1<boost::_bi::value<Monitor *>>> >' requested here boost::function<void (int, int)> f(b); ^ 1 error generated.

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Compilation Problem Boost 1.50
by saugat mitra 13 Aug '12

13 Aug '12

Hi I am trying yo compile Secret Maryo Chronicles SMC 1,9 on my Ubuntu machine 11.10 . I have installed Boost 1.50.0. But when I run make I get the following error - [code] core/filesystem/filesystem.cpp: In function ‘bool SMC::Dir_Exists(const string&)’: core/filesystem/filesystem.cpp:67:47: error: invalid conversion from ‘bool (*)(const string&) {aka bool (*)(const std::basic_string<char>&)}’ to ‘boost::enable_if_c<true, void>::type* {aka void*}’ [-fpermissive] /usr/include/boost/filesystem/v3/path.hpp:130:5: error: initializing argument 2 of ‘boost::filesystem3::path::path(const Source&, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type> >::type*) [with Source = std::basic_string<char>, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type> >::type = void]’ [-fpermissive] core/filesystem/filesystem.cpp: In function ‘bool SMC::Create_Directory(const string&)’: core/filesystem/filesystem.cpp:92:57: error: invalid conversion from ‘bool (*)(const string&) {aka bool (*)(const std::basic_string<char>&)}’ to ‘boost::enable_if_c<true, void>::type* {aka void*}’ [-fpermissive] /usr/include/boost/filesystem/v3/path.hpp:130:5: error: initializing argument 2 of ‘boost::filesystem3::path::path(const Source&, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type> >::type*) [with Source = std::basic_string<char>, typename boost::enable_if<boost::filesystem3::path_traits::is_pathable<typename boost::decay<Source>::type> >::type = void]’ [-fpermissive] core/filesystem/filesystem.cpp: In function ‘std::vector<std::basic_string<char> > SMC::Get_Directory_Files(const string&, const string&, bool, bool)’: [/code] Any help would be much appreciated. Thanks.

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[lexical_cast] is it possible to customize the conversion from double to string?
by Wu Degang 13 Aug '12

13 Aug '12

Hi, The default behavior of lexical_cast<string>(a_double_variable) will result in a number string that is very long and barely readable. Is it possible to customize the way lexical_cast<string>(a_double_variable) can have a similar result as '%.2f' or '%.3e'? Thank you! wdg

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request: plz add operator() to mpl::true_ and mpl::false_
by Niitsuma Hirotaka 12 Aug '12

12 Aug '12

plz add operator() to mpl::true_ and mpl_::false let us consider the following case. struct foo{}; template<typename T> struct is_foo_traits : boost::mpl::false_ {}; template<> struct is_foo_traits<foo> : boost::mpl::true_ {}; template<typename T> bool is_foo(const T& dummy){return false;} template<> bool is_foo<foo>(const foo& dummy){return true;} void main() { using namespace boost; using namespace std; foo myfoo; cout << is_foo(myfoo) << endl;//true cout << is_foo(12) << endl;//false cout << is_foo_traits<foo>::value << endl;//true cout << is_foo_traits<int>::value << endl;//false } In this case, we need to define same thing two times. However if mpl::true_ have operator() as like mpl::true_ { template<typename T> bool operator()(const T & dummy){return true;} }; We can remove one line using: template<typename T> bool is_foo(const T& dummy){return is_foo_traits<T>::value;}

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Boost, Andoird and iOS
by Mohsen Pahlevanzadeh 12 Aug '12

12 Aug '12

Dear all, We are developing an application under GNU/Linux, But we `must` code it multiplatform, So, i don't know when i use boost can i use it under Android and iOS or not? --Mohsen

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