boost/intrusive/pointer_traits.hpp
////////////////////////////////////////////////////////////////////////////// // // (C) Copyright Pablo Halpern 2009. 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) // ////////////////////////////////////////////////////////////////////////////// // // (C) Copyright Ion Gaztanaga 2011-2013. 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/intrusive for documentation. // ////////////////////////////////////////////////////////////////////////////// #ifndef BOOST_INTRUSIVE_POINTER_TRAITS_HPP #define BOOST_INTRUSIVE_POINTER_TRAITS_HPP #if defined(_MSC_VER) # pragma once #endif #include <boost/intrusive/detail/config_begin.hpp> #include <boost/intrusive/intrusive_fwd.hpp> #include <boost/intrusive/detail/workaround.hpp> #include <boost/intrusive/detail/memory_util.hpp> #include <boost/intrusive/detail/mpl.hpp> #include <cstddef> namespace boost { namespace intrusive { //! pointer_traits is the implementation of C++11 std::pointer_traits class with some //! extensions like castings. //! //! pointer_traits supplies a uniform interface to certain attributes of pointer-like types. template <typename Ptr> struct pointer_traits { #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //!The pointer type //!queried by this pointer_traits instantiation typedef Ptr pointer; //!Ptr::element_type if such a type exists; otherwise, T if Ptr is a class //!template instantiation of the form SomePointer<T, Args>, where Args is zero or //!more type arguments ; otherwise , the specialization is ill-formed. typedef unspecified_type element_type; //!Ptr::difference_type if such a type exists; otherwise, //!std::ptrdiff_t. typedef unspecified_type difference_type; //!Ptr::rebind<U> if such a type exists; otherwise, SomePointer<U, Args> if Ptr is //!a class template instantiation of the form SomePointer<T, Args>, where Args is zero or //!more type arguments ; otherwise, the instantiation of rebind is ill-formed. //! //!For portable code for C++03 and C++11, <pre>typename rebind_pointer<U>::type</pre> //!shall be used instead of rebind<U> to obtain a pointer to U. template <class U> using rebind = unspecified; //!Ptr::reference if such a type exists (non-standard extension); otherwise, element_type & //! typedef element_type &reference; #else typedef Ptr pointer; // typedef BOOST_INTRUSIVE_OBTAIN_TYPE_WITH_EVAL_DEFAULT ( boost::intrusive::detail::, Ptr, element_type , boost::intrusive::detail::first_param<Ptr>) element_type; // typedef BOOST_INTRUSIVE_OBTAIN_TYPE_WITH_DEFAULT (boost::intrusive::detail::, Ptr, difference_type, std::ptrdiff_t) difference_type; typedef BOOST_INTRUSIVE_OBTAIN_TYPE_WITH_DEFAULT (boost::intrusive::detail::, Ptr, reference, typename boost::intrusive::detail::unvoid_ref<element_type>::type) reference; // template <class U> struct rebind_pointer { typedef typename boost::intrusive::detail::type_rebinder<Ptr, U>::type type; }; #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) template <class U> using rebind = typename boost::intrusive::detail::type_rebinder<Ptr, U>::type; #endif #endif //#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) //! <b>Remark</b>: If element_type is (possibly cv-qualified) void, r type is unspecified; otherwise, //! it is element_type &. //! //! <b>Returns</b>: A dereferenceable pointer to r obtained by calling Ptr::pointer_to(r). //! Non-standard extension: If such function does not exist, returns pointer(addressof(r)); static pointer pointer_to(reference r) { //Non-standard extension, it does not require Ptr::pointer_to. If not present //tries to converts &r to pointer. const bool value = boost::intrusive::detail:: has_member_function_callable_with_pointer_to <Ptr, reference>::value; boost::intrusive::detail::bool_<value> flag; return pointer_traits::priv_pointer_to(flag, r); } //! <b>Remark</b>: Non-standard extension. //! //! <b>Returns</b>: A dereferenceable pointer to r obtained by calling Ptr::static_cast_from(r). //! If such function does not exist, returns pointer_to(static_cast<element_type&>(*uptr)) template<class UPtr> static pointer static_cast_from(const UPtr &uptr) { const bool value = boost::intrusive::detail:: has_member_function_callable_with_static_cast_from <Ptr, const UPtr>::value; boost::intrusive::detail::bool_<value> flag; return pointer_traits::priv_static_cast_from(flag, uptr); } //! <b>Remark</b>: Non-standard extension. //! //! <b>Returns</b>: A dereferenceable pointer to r obtained by calling Ptr::const_cast_from(r). //! If such function does not exist, returns pointer_to(const_cast<element_type&>(*uptr)) template<class UPtr> static pointer const_cast_from(const UPtr &uptr) { const bool value = boost::intrusive::detail:: has_member_function_callable_with_const_cast_from <Ptr, const UPtr>::value; boost::intrusive::detail::bool_<value> flag; return pointer_traits::priv_const_cast_from(flag, uptr); } //! <b>Remark</b>: Non-standard extension. //! //! <b>Returns</b>: A dereferenceable pointer to r obtained by calling Ptr::dynamic_cast_from(r). //! If such function does not exist, returns pointer_to(*dynamic_cast<element_type*>(&*uptr)) template<class UPtr> static pointer dynamic_cast_from(const UPtr &uptr) { const bool value = boost::intrusive::detail:: has_member_function_callable_with_dynamic_cast_from <Ptr, const UPtr>::value; boost::intrusive::detail::bool_<value> flag; return pointer_traits::priv_dynamic_cast_from(flag, uptr); } ///@cond private: //priv_to_raw_pointer template <class T> static T* to_raw_pointer(T* p) { return p; } template <class Pointer> static typename pointer_traits<Pointer>::element_type* to_raw_pointer(const Pointer &p) { return pointer_traits::to_raw_pointer(p.operator->()); } //priv_pointer_to static pointer priv_pointer_to(boost::intrusive::detail::true_, reference r) { return Ptr::pointer_to(r); } static pointer priv_pointer_to(boost::intrusive::detail::false_, reference r) { return pointer(boost::intrusive::detail::addressof(r)); } //priv_static_cast_from template<class UPtr> static pointer priv_static_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) { return Ptr::static_cast_from(uptr); } template<class UPtr> static pointer priv_static_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) { return pointer_to(*static_cast<element_type*>(to_raw_pointer(uptr))); } //priv_const_cast_from template<class UPtr> static pointer priv_const_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) { return Ptr::const_cast_from(uptr); } template<class UPtr> static pointer priv_const_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) { return pointer_to(const_cast<element_type&>(*uptr)); } //priv_dynamic_cast_from template<class UPtr> static pointer priv_dynamic_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) { return Ptr::dynamic_cast_from(uptr); } template<class UPtr> static pointer priv_dynamic_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) { element_type *p = dynamic_cast<element_type*>(&*uptr); if(!p){ return pointer(); } else{ return pointer_to(*p); } } ///@endcond }; ///@cond // Remove cv qualification from Ptr parameter to pointer_traits: template <typename Ptr> struct pointer_traits<const Ptr> : pointer_traits<Ptr> {}; template <typename Ptr> struct pointer_traits<volatile Ptr> : pointer_traits<Ptr> { }; template <typename Ptr> struct pointer_traits<const volatile Ptr> : pointer_traits<Ptr> { }; // Remove reference from Ptr parameter to pointer_traits: template <typename Ptr> struct pointer_traits<Ptr&> : pointer_traits<Ptr> { }; ///@endcond //! Specialization of pointer_traits for raw pointers //! template <typename T> struct pointer_traits<T*> { typedef T element_type; typedef T* pointer; typedef std::ptrdiff_t difference_type; #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED typedef T & reference; //!typedef for <pre>U *</pre> //! //!For portable code for C++03 and C++11, <pre>typename rebind_pointer<U>::type</pre> //!shall be used instead of rebind<U> to obtain a pointer to U. template <class U> using rebind = U*; #else typedef typename boost::intrusive::detail::unvoid_ref<element_type>::type reference; #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) template <class U> using rebind = U*; #endif #endif template <class U> struct rebind_pointer { typedef U* type; }; //! <b>Returns</b>: addressof(r) //! static pointer pointer_to(reference r) { return boost::intrusive::detail::addressof(r); } //! <b>Returns</b>: static_cast<pointer>(uptr) //! template<class U> static pointer static_cast_from(U *uptr) { return static_cast<pointer>(uptr); } //! <b>Returns</b>: const_cast<pointer>(uptr) //! template<class U> static pointer const_cast_from(U *uptr) { return const_cast<pointer>(uptr); } //! <b>Returns</b>: dynamic_cast<pointer>(uptr) //! template<class U> static pointer dynamic_cast_from(U *uptr) { return dynamic_cast<pointer>(uptr); } }; } //namespace container { } //namespace boost { #include <boost/intrusive/detail/config_end.hpp> #endif // ! defined(BOOST_INTRUSIVE_POINTER_TRAITS_HPP)