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Editing: is_forward_iterable.hpp
// (C) Copyright Gennadiy Rozental 2001. // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // See http://www.boost.org/libs/test for the library home page. // //! @file //! Defines the is_forward_iterable collection type trait // *************************************************************************** #ifndef BOOST_TEST_UTILS_IS_FORWARD_ITERABLE_HPP #define BOOST_TEST_UTILS_IS_FORWARD_ITERABLE_HPP #if defined(BOOST_NO_CXX11_DECLTYPE) || \ defined(BOOST_NO_CXX11_NULLPTR) || \ defined(BOOST_NO_CXX11_TRAILING_RESULT_TYPES) // this feature works with VC2012 upd 5 while BOOST_NO_CXX11_TRAILING_RESULT_TYPES is defined #if !defined(BOOST_MSVC) || BOOST_MSVC_FULL_VER < 170061232 /* VC2012 upd 5 */ #define BOOST_TEST_FWD_ITERABLE_CXX03 #endif #endif #if defined(BOOST_TEST_FWD_ITERABLE_CXX03) // Boost #include <boost/mpl/bool.hpp> // STL #include <list> #include <vector> #include <map> #include <set> #else // Boost #include <boost/static_assert.hpp> #include <boost/utility/declval.hpp> #include <boost/type_traits/is_same.hpp> #include <boost/type_traits/remove_reference.hpp> #include <boost/type_traits/remove_cv.hpp> #include <boost/test/utils/is_cstring.hpp> // STL #include <utility> #include <type_traits> #endif //____________________________________________________________________________// namespace boost { namespace unit_test { template<typename T> struct is_forward_iterable; // ************************************************************************** // // ************** is_forward_iterable ************** // // ************************************************************************** // #if defined(BOOST_TEST_FWD_ITERABLE_CXX03) && !defined(BOOST_TEST_DOXYGEN_DOC__) template<typename T> struct is_forward_iterable : public mpl::false_ {}; template<typename T> struct is_forward_iterable<T const> : public is_forward_iterable<T> {}; template<typename T> struct is_forward_iterable<T&> : public is_forward_iterable<T> {}; template<typename T, std::size_t N> struct is_forward_iterable< T [N] > : public mpl::true_ {}; template<typename T, typename A> struct is_forward_iterable< std::vector<T, A> > : public mpl::true_ {}; template<typename T, typename A> struct is_forward_iterable< std::list<T, A> > : public mpl::true_ {}; template<typename K, typename V, typename C, typename A> struct is_forward_iterable< std::map<K, V, C, A> > : public mpl::true_ {}; template<typename K, typename C, typename A> struct is_forward_iterable< std::set<K, C, A> > : public mpl::true_ {}; // string is also forward iterable, even if sometimes we want to treat the // assertions differently. template<> struct is_forward_iterable< std::string > : public mpl::true_ {}; #else namespace ut_detail { // SFINAE helper template<typename T> struct is_present : public mpl::true_ {}; //____________________________________________________________________________// // some compiler do not implement properly decltype non expression involving members (eg. VS2013) // a workaround is to use -> decltype syntax. template <class T> struct has_member_size { private: struct nil_t {}; template<typename U> static auto test( U* ) -> decltype(boost::declval<U>().size()); template<typename> static nil_t test( ... ); public: static bool const value = !std::is_same< decltype(test<T>( nullptr )), nil_t>::value; }; //____________________________________________________________________________// template <class T> struct has_member_begin { private: struct nil_t {}; template<typename U> static auto test( U* ) -> decltype(std::begin(boost::declval<U&>())); // does not work with boost::begin template<typename> static nil_t test( ... ); public: static bool const value = !std::is_same< decltype(test<T>( nullptr )), nil_t>::value; }; //____________________________________________________________________________// template <class T> struct has_member_end { private: struct nil_t {}; template<typename U> static auto test( U* ) -> decltype(std::end(boost::declval<U&>())); // does not work with boost::end template<typename> static nil_t test( ... ); public: static bool const value = !std::is_same< decltype(test<T>( nullptr )), nil_t>::value; }; //____________________________________________________________________________// template <class T, class enabled = void> struct is_forward_iterable_impl : std::false_type { }; template <class T> struct is_forward_iterable_impl< T, typename std::enable_if< has_member_begin<T>::value && has_member_end<T>::value >::type > : std::true_type {}; //____________________________________________________________________________// template <class T, class enabled = void> struct is_container_forward_iterable_impl : std::false_type { }; template <class T> struct is_container_forward_iterable_impl< T, typename std::enable_if< is_present<typename T::const_iterator>::value && is_present<typename T::value_type>::value && has_member_size<T>::value && is_forward_iterable_impl<T>::value >::type > : is_forward_iterable_impl<T> {}; //____________________________________________________________________________// } // namespace ut_detail /*! Indicates that a specific type implements the forward iterable concept. */ template<typename T> struct is_forward_iterable { typedef typename std::remove_reference<T>::type T_ref; typedef ut_detail::is_forward_iterable_impl<T_ref> is_fwd_it_t; typedef mpl::bool_<is_fwd_it_t::value> type; enum { value = is_fwd_it_t::value }; }; /*! Indicates that a specific type implements the forward iterable concept. */ template<typename T> struct is_container_forward_iterable { typedef typename std::remove_reference<T>::type T_ref; typedef ut_detail::is_container_forward_iterable_impl<T_ref> is_fwd_it_t; typedef mpl::bool_<is_fwd_it_t::value> type; enum { value = is_fwd_it_t::value }; }; #endif /* defined(BOOST_TEST_FWD_ITERABLE_CXX03) */ //! Helper structure for accessing the content of a container or an array template <typename T, bool is_forward_iterable = is_forward_iterable<T>::value > struct bt_iterator_traits; template <typename T> struct bt_iterator_traits< T, true >{ BOOST_STATIC_ASSERT((is_forward_iterable<T>::value)); #if defined(BOOST_TEST_FWD_ITERABLE_CXX03) || \ (defined(BOOST_MSVC) && (BOOST_MSVC_FULL_VER <= 170061232)) typedef typename T::const_iterator const_iterator; typedef typename std::iterator_traits<const_iterator>::value_type value_type; #else typedef decltype(boost::declval< typename boost::add_const< typename boost::remove_reference<T>::type >::type>().begin()) const_iterator; typedef typename std::iterator_traits<const_iterator>::value_type value_type; #endif /* BOOST_TEST_FWD_ITERABLE_CXX03 */ static const_iterator begin(T const& container) { return container.begin(); } static const_iterator end(T const& container) { return container.end(); } #if defined(BOOST_TEST_FWD_ITERABLE_CXX03) || \ (defined(BOOST_MSVC) && (BOOST_MSVC_FULL_VER <= 170061232)) static std::size_t size(T const& container) { return container.size(); } #else static std::size_t size(T const& container) { return size(container, std::integral_constant<bool, ut_detail::has_member_size<T>::value>()); } private: static std::size_t size(T const& container, std::true_type) { return container.size(); } static std::size_t size(T const& container, std::false_type) { return std::distance(begin(container), end(container)); } #endif /* BOOST_TEST_FWD_ITERABLE_CXX03 */ }; template <typename T, std::size_t N> struct bt_iterator_traits< T [N], true > { typedef typename boost::add_const<T>::type T_const; typedef typename boost::add_pointer<T_const>::type const_iterator; typedef T value_type; static const_iterator begin(T_const (&array)[N]) { return &array[0]; } static const_iterator end(T_const (&array)[N]) { return &array[N]; } static std::size_t size(T_const (&)[N]) { return N; } }; } // namespace unit_test } // namespace boost #endif // BOOST_TEST_UTILS_IS_FORWARD_ITERABLE_HPP
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