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 2011-2014. 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
#include <boost/intrusive/detail/config_begin.hpp>
#include <boost/intrusive/detail/workaround.hpp>
#include <boost/intrusive/pointer_rebind.hpp>
#include <boost/intrusive/detail/pointer_element.hpp>
#include <boost/intrusive/detail/mpl.hpp>
#include <cstddef>
#if defined(BOOST_HAS_PRAGMA_ONCE)
# pragma once
#endif
namespace boost {
namespace intrusive {
namespace detail {
#if !defined(BOOST_MSVC) || (BOOST_MSVC > 1310)
BOOST_INTRUSIVE_HAS_STATIC_MEMBER_FUNC_SIGNATURE(has_member_function_callable_with_pointer_to, pointer_to)
BOOST_INTRUSIVE_HAS_STATIC_MEMBER_FUNC_SIGNATURE(has_member_function_callable_with_dynamic_cast_from, dynamic_cast_from)
BOOST_INTRUSIVE_HAS_STATIC_MEMBER_FUNC_SIGNATURE(has_member_function_callable_with_static_cast_from, static_cast_from)
BOOST_INTRUSIVE_HAS_STATIC_MEMBER_FUNC_SIGNATURE(has_member_function_callable_with_const_cast_from, const_cast_from)
#else
BOOST_INTRUSIVE_HAS_MEMBER_FUNC_CALLED_IGNORE_SIGNATURE(has_member_function_callable_with_pointer_to, pointer_to)
BOOST_INTRUSIVE_HAS_MEMBER_FUNC_CALLED_IGNORE_SIGNATURE(has_member_function_callable_with_dynamic_cast_from, dynamic_cast_from)
BOOST_INTRUSIVE_HAS_MEMBER_FUNC_CALLED_IGNORE_SIGNATURE(has_member_function_callable_with_static_cast_from, static_cast_from)
BOOST_INTRUSIVE_HAS_MEMBER_FUNC_CALLED_IGNORE_SIGNATURE(has_member_function_callable_with_const_cast_from, const_cast_from)
#endif
BOOST_INTRUSIVE_INSTANTIATE_EVAL_DEFAULT_TYPE_TMPLT(element_type)
BOOST_INTRUSIVE_INSTANTIATE_DEFAULT_TYPE_TMPLT(difference_type)
BOOST_INTRUSIVE_INSTANTIATE_DEFAULT_TYPE_TMPLT(reference)
BOOST_INTRUSIVE_INSTANTIATE_DEFAULT_TYPE_TMPLT(value_traits_ptr)
} //namespace detail {
//! 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.
//!
//! <b>Note</b>: When defining a custom family of pointers or references to be used with BI
//! library, make sure the public static conversion functions accessed through
//! the `pointer_traits` interface (`*_cast_from` and `pointer_to`) can
//! properly convert between const and nonconst referred member types
//! <b>without the use of implicit constructor calls</b>. It is suggested these
//! conversions be implemented as function templates, where the template
//! argument is the type of the object being converted from.
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 unspecified_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::pointer_rebind<Ptr, U>::type type;
};
#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
template <class U> using rebind = typename boost::intrusive::pointer_rebind<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(reference).
//! Non-standard extension: If such function does not exist, returns pointer(addressof(r));
//!
//! <b>Note</b>: For non-conforming compilers only the existence of a member function called
//! <code>pointer_to</code> is checked.
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, 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 the static template function
//! Ptr::static_cast_from(UPpr/const UPpr &).
//! If such function does not exist, returns pointer_to(static_cast<element_type&>(*uptr))
//!
//! <b>Note</b>: For non-conforming compilers only the existence of a member function called
//! <code>static_cast_from</code> is checked.
template<class UPtr>
static pointer static_cast_from(const UPtr &uptr)
{
typedef const UPtr &RefArg;
const bool value = boost::intrusive::detail::
has_member_function_callable_with_static_cast_from
<pointer, pointer(*)(RefArg)>::value
|| boost::intrusive::detail::
has_member_function_callable_with_static_cast_from
<pointer, pointer(*)(UPtr)>::value;
return pointer_traits::priv_static_cast_from(boost::intrusive::detail::bool_<value>(), uptr);
}
//! <b>Remark</b>: Non-standard extension.
//!
//! <b>Returns</b>: A dereferenceable pointer to r obtained by calling the static template function
//! Ptr::const_cast_from<UPtr>(UPpr/const UPpr &).
//! If such function does not exist, returns pointer_to(const_cast<element_type&>(*uptr))
//!
//! <b>Note</b>: For non-conforming compilers only the existence of a member function called
//! <code>const_cast_from</code> is checked.
template<class UPtr>
static pointer const_cast_from(const UPtr &uptr)
{
typedef const UPtr &RefArg;
const bool value = boost::intrusive::detail::
has_member_function_callable_with_const_cast_from
<pointer, pointer(*)(RefArg)>::value
|| boost::intrusive::detail::
has_member_function_callable_with_const_cast_from
<pointer, pointer(*)(UPtr)>::value;
return pointer_traits::priv_const_cast_from(boost::intrusive::detail::bool_<value>(), uptr);
}
//! <b>Remark</b>: Non-standard extension.
//!
//! <b>Returns</b>: A dereferenceable pointer to r obtained by calling the static template function
//! Ptr::dynamic_cast_from<UPtr>(UPpr/const UPpr &).
//! If such function does not exist, returns pointer_to(*dynamic_cast<element_type*>(&*uptr))
//!
//! <b>Note</b>: For non-conforming compilers only the existence of a member function called
//! <code>dynamic_cast_from</code> is checked.
template<class UPtr>
static pointer dynamic_cast_from(const UPtr &uptr)
{
typedef const UPtr &RefArg;
const bool value = boost::intrusive::detail::
has_member_function_callable_with_dynamic_cast_from
<pointer, pointer(*)(RefArg)>::value
|| boost::intrusive::detail::
has_member_function_callable_with_dynamic_cast_from
<pointer, pointer(*)(UPtr)>::value;
return pointer_traits::priv_dynamic_cast_from(boost::intrusive::detail::bool_<value>(), 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)