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- //////////////////////////////////////////////////////////////////////////////
- //
- // (C) Copyright Ion Gaztanaga 2005-2015. 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/interprocess for documentation.
- //
- //////////////////////////////////////////////////////////////////////////////
- #ifndef BOOST_INTERPROCESS_OFFSET_PTR_HPP
- #define BOOST_INTERPROCESS_OFFSET_PTR_HPP
- #ifndef BOOST_CONFIG_HPP
- # include <boost/config.hpp>
- #endif
- #
- #if defined(BOOST_HAS_PRAGMA_ONCE)
- # pragma once
- #endif
- #include <boost/interprocess/detail/config_begin.hpp>
- #include <boost/interprocess/detail/workaround.hpp>
- #include <boost/type_traits/is_convertible.hpp>
- #include <boost/type_traits/is_constructible.hpp>
- #include <boost/type_traits/is_integral.hpp>
- #include <boost/type_traits/is_unsigned.hpp>
- #include <boost/interprocess/interprocess_fwd.hpp>
- #include <boost/interprocess/detail/utilities.hpp>
- #include <boost/interprocess/detail/cast_tags.hpp>
- #include <boost/interprocess/detail/mpl.hpp>
- #include <boost/container/detail/type_traits.hpp> //alignment_of, aligned_storage
- #include <boost/assert.hpp>
- #include <iosfwd>
- //!\file
- //!Describes a smart pointer that stores the offset between this pointer and
- //!target pointee, called offset_ptr.
- namespace boost {
- #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
- //Predeclarations
- template <class T>
- struct has_trivial_destructor;
- #endif //#if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
- namespace interprocess {
- #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
- namespace ipcdetail {
- template<class OffsetType, std::size_t OffsetAlignment>
- union offset_ptr_internal
- {
- BOOST_STATIC_ASSERT(sizeof(OffsetType) >= sizeof(uintptr_t));
- BOOST_STATIC_ASSERT(boost::is_integral<OffsetType>::value && boost::is_unsigned<OffsetType>::value);
- explicit offset_ptr_internal(OffsetType off)
- : m_offset(off)
- {}
- OffsetType m_offset; //Distance between this object and pointee address
- typename ::boost::container::dtl::aligned_storage
- < sizeof(OffsetType)//for offset_type_alignment m_offset will be enough
- , (OffsetAlignment == offset_type_alignment) ? 1u : OffsetAlignment
- >::type alignment_helper;
- };
- //Note: using the address of a local variable to point to another address
- //is not standard conforming and this can be optimized-away by the compiler.
- //Non-inlining is a method to remain illegal but correct
- //Undef BOOST_INTERPROCESS_OFFSET_PTR_INLINE_XXX if your compiler can inline
- //this code without breaking the library
- ////////////////////////////////////////////////////////////////////////
- //
- // offset_ptr_to_raw_pointer
- //
- ////////////////////////////////////////////////////////////////////////
- #define BOOST_INTERPROCESS_OFFSET_PTR_BRANCHLESS_TO_PTR
- template <class OffsetType>
- BOOST_INTERPROCESS_FORCEINLINE void * offset_ptr_to_raw_pointer(const volatile void *this_ptr, OffsetType offset)
- {
- typedef pointer_offset_caster<void*, OffsetType> caster_t;
- #ifndef BOOST_INTERPROCESS_OFFSET_PTR_BRANCHLESS_TO_PTR
- if(offset == 1){
- return 0;
- }
- else{
- return caster_t(caster_t(this_ptr).offset() + offset).pointer();
- }
- #else
- OffsetType mask = offset == 1;
- --mask;
- OffsetType target_offset = caster_t(this_ptr).offset() + offset;
- target_offset &= mask;
- return caster_t(target_offset).pointer();
- #endif
- }
- ////////////////////////////////////////////////////////////////////////
- //
- // offset_ptr_to_offset
- //
- ////////////////////////////////////////////////////////////////////////
- #define BOOST_INTERPROCESS_OFFSET_PTR_BRANCHLESS_TO_OFF
- template<class OffsetType>
- BOOST_INTERPROCESS_FORCEINLINE OffsetType offset_ptr_to_offset(const volatile void *ptr, const volatile void *this_ptr)
- {
- typedef pointer_offset_caster<void*, OffsetType> caster_t;
- #ifndef BOOST_INTERPROCESS_OFFSET_PTR_BRANCHLESS_TO_OFF
- //offset == 1 && ptr != 0 is not legal for this pointer
- if(!ptr){
- return 1;
- }
- else{
- OffsetType offset = caster_t(ptr).offset()- caster_t(this_ptr).offset();
- BOOST_ASSERT(offset != 1);
- return offset;
- }
- #else
- //const OffsetType other = -OffsetType(ptr != 0);
- //const OffsetType offset = (caster_t(ptr).offset() - caster_t(this_ptr).offset()) & other;
- //return offset + OffsetType(!other);
- //
- OffsetType offset = caster_t(ptr).offset() - caster_t(this_ptr).offset();
- --offset;
- OffsetType mask = ptr == 0;
- --mask;
- offset &= mask;
- return ++offset;
- #endif
- }
- ////////////////////////////////////////////////////////////////////////
- //
- // offset_ptr_to_offset_from_other
- //
- ////////////////////////////////////////////////////////////////////////
- #define BOOST_INTERPROCESS_OFFSET_PTR_BRANCHLESS_TO_OFF_FROM_OTHER
- template<class OffsetType>
- BOOST_INTERPROCESS_FORCEINLINE OffsetType offset_ptr_to_offset_from_other
- (const volatile void *this_ptr, const volatile void *other_ptr, OffsetType other_offset)
- {
- typedef pointer_offset_caster<void*, OffsetType> caster_t;
- #ifndef BOOST_INTERPROCESS_OFFSET_PTR_BRANCHLESS_TO_OFF_FROM_OTHER
- if(other_offset == 1){
- return 1;
- }
- else{
- OffsetType offset = caster_t(other_ptr).offset() - caster_t(this_ptr).offset() + other_offset;
- BOOST_ASSERT(offset != 1);
- return offset;
- }
- #else
- OffsetType mask = other_offset == 1;
- --mask;
- OffsetType offset = caster_t(other_ptr).offset() - caster_t(this_ptr).offset();
- offset &= mask;
- return offset + other_offset;
- //OffsetType mask = -OffsetType(other_offset != 1);
- //OffsetType offset = caster_t(other_ptr).offset() - caster_t(this_ptr).offset();
- //offset &= mask;
- //return offset + other_offset;
- #endif
- }
- ////////////////////////////////////////////////////////////////////////
- //
- // Let's assume cast to void and cv cast don't change any target address
- //
- ////////////////////////////////////////////////////////////////////////
- template<class From, class To>
- struct offset_ptr_maintains_address
- {
- static const bool value = ipcdetail::is_cv_same<From, To>::value
- || ipcdetail::is_cv_same<void, To>::value
- || ipcdetail::is_cv_same<char, To>::value
- ;
- };
- template<class From, class To, class Ret = void>
- struct enable_if_convertible_equal_address
- : enable_if_c< ::boost::is_convertible<From*, To*>::value
- && offset_ptr_maintains_address<From, To>::value
- , Ret>
- {};
- template<class From, class To, class Ret = void>
- struct enable_if_convertible_unequal_address
- : enable_if_c< ::boost::is_convertible<From*, To*>::value
- && !offset_ptr_maintains_address<From, To>::value
- , Ret>
- {};
- } //namespace ipcdetail {
- #endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- //!A smart pointer that stores the offset between between the pointer and the
- //!the object it points. This allows offset allows special properties, since
- //!the pointer is independent from the address of the pointee, if the
- //!pointer and the pointee are still separated by the same offset. This feature
- //!converts offset_ptr in a smart pointer that can be placed in shared memory and
- //!memory mapped files mapped in different addresses in every process.
- //!
- //! \tparam PointedType The type of the pointee.
- //! \tparam DifferenceType A signed integer type that can represent the arithmetic operations on the pointer
- //! \tparam OffsetType An unsigned integer type that can represent the
- //! distance between two pointers reinterpret_cast-ed as unsigned integers. This type
- //! should be at least of the same size of std::uintptr_t. In some systems it's possible to communicate
- //! between 32 and 64 bit processes using 64 bit offsets.
- //! \tparam OffsetAlignment Alignment of the OffsetType stored inside. In some systems might be necessary
- //! to align it to 64 bits in order to communicate 32 and 64 bit processes using 64 bit offsets.
- //!
- //!<b>Note</b>: offset_ptr uses implementation defined properties, present in most platforms, for
- //!performance reasons:
- //! - Assumes that OffsetType representation of nullptr is (OffsetType)zero.
- //! - Assumes that incrementing a OffsetType obtained from a pointer is equivalent
- //! to incrementing the pointer and then converting it back to OffsetType.
- template <class PointedType, class DifferenceType, class OffsetType, std::size_t OffsetAlignment>
- class offset_ptr
- {
- #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
- typedef offset_ptr<PointedType, DifferenceType, OffsetType, OffsetAlignment> self_t;
- void unspecified_bool_type_func() const {}
- typedef void (self_t::*unspecified_bool_type)() const;
- #endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- public:
- typedef PointedType element_type;
- typedef PointedType * pointer;
- typedef typename ipcdetail::
- add_reference<PointedType>::type reference;
- typedef typename ipcdetail::
- remove_volatile<typename ipcdetail::
- remove_const<PointedType>::type
- >::type value_type;
- typedef DifferenceType difference_type;
- typedef std::random_access_iterator_tag iterator_category;
- typedef OffsetType offset_type;
- public: //Public Functions
- //!Default constructor (null pointer).
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr() BOOST_NOEXCEPT
- : internal(1)
- {}
- //!Constructor from raw pointer (allows "0" pointer conversion).
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr(pointer ptr) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset<OffsetType>(ptr, this))
- {}
- //!Constructor from other pointer.
- //!Never throws.
- template <class T>
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr( T *ptr
- , typename ipcdetail::enable_if< ::boost::is_convertible<T*, PointedType*> >::type * = 0) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset<OffsetType>(static_cast<PointedType*>(ptr), this))
- {}
- //!Constructor from other offset_ptr
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr(const offset_ptr& ptr) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset_from_other(this, &ptr, ptr.internal.m_offset))
- {}
- //!Constructor from other offset_ptr. Only takes part in overload resolution
- //!if T2* is convertible to PointedType*. Never throws.
- template<class T2>
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr( const offset_ptr<T2, DifferenceType, OffsetType, OffsetAlignment> &ptr
- #ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- , typename ipcdetail::enable_if_convertible_equal_address<T2, PointedType>::type* = 0
- #endif
- ) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset_from_other(this, &ptr, ptr.get_offset()))
- {}
- #ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- template<class T2>
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr( const offset_ptr<T2, DifferenceType, OffsetType, OffsetAlignment> &ptr
- , typename ipcdetail::enable_if_convertible_unequal_address<T2, PointedType>::type* = 0) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset<OffsetType>(static_cast<PointedType*>(ptr.get()), this))
- {}
- #endif
- //!Constructor from other offset_ptr. Only takes part in overload resolution
- //!if PointedType* is constructible from T2* other than via a conversion (e.g. cast to a derived class). Never throws.
- template<class T2>
- BOOST_INTERPROCESS_FORCEINLINE explicit offset_ptr(const offset_ptr<T2, DifferenceType, OffsetType, OffsetAlignment> &ptr
- #ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- , typename ipcdetail::enable_if_c<
- !::boost::is_convertible<T2*, PointedType*>::value && ::boost::is_constructible<T2*, PointedType*>::value
- >::type * = 0
- #endif
- ) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset<OffsetType>(static_cast<PointedType*>(ptr.get()), this))
- {}
- //!Emulates static_cast operator.
- //!Never throws.
- template<class T2, class P2, class O2, std::size_t A2>
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr(const offset_ptr<T2, P2, O2, A2> & r, ipcdetail::static_cast_tag) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset<OffsetType>(static_cast<PointedType*>(r.get()), this))
- {}
- //!Emulates const_cast operator.
- //!Never throws.
- template<class T2, class P2, class O2, std::size_t A2>
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr(const offset_ptr<T2, P2, O2, A2> & r, ipcdetail::const_cast_tag) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset<OffsetType>(const_cast<PointedType*>(r.get()), this))
- {}
- //!Emulates dynamic_cast operator.
- //!Never throws.
- template<class T2, class P2, class O2, std::size_t A2>
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr(const offset_ptr<T2, P2, O2, A2> & r, ipcdetail::dynamic_cast_tag) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset<OffsetType>(dynamic_cast<PointedType*>(r.get()), this))
- {}
- //!Emulates reinterpret_cast operator.
- //!Never throws.
- template<class T2, class P2, class O2, std::size_t A2>
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr(const offset_ptr<T2, P2, O2, A2> & r, ipcdetail::reinterpret_cast_tag) BOOST_NOEXCEPT
- : internal(ipcdetail::offset_ptr_to_offset<OffsetType>(reinterpret_cast<PointedType*>(r.get()), this))
- {}
- //!Obtains raw pointer from offset.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE pointer get() const BOOST_NOEXCEPT
- { return static_cast<pointer>(ipcdetail::offset_ptr_to_raw_pointer(this, this->internal.m_offset)); }
- BOOST_INTERPROCESS_FORCEINLINE offset_type get_offset() const BOOST_NOEXCEPT
- { return this->internal.m_offset; }
- //!Pointer-like -> operator. It can return 0 pointer.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE pointer operator->() const BOOST_NOEXCEPT
- { return this->get(); }
- //!Dereferencing operator, if it is a null offset_ptr behavior
- //! is undefined. Never throws.
- BOOST_INTERPROCESS_FORCEINLINE reference operator* () const BOOST_NOEXCEPT
- {
- pointer p = this->get();
- reference r = *p;
- return r;
- }
- //!Indexing operator.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE reference operator[](difference_type idx) const BOOST_NOEXCEPT
- { return this->get()[idx]; }
- //!Assignment from pointer (saves extra conversion).
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr& operator= (pointer from) BOOST_NOEXCEPT
- {
- this->internal.m_offset = ipcdetail::offset_ptr_to_offset<OffsetType>(from, this);
- return *this;
- }
- //!Assignment from other offset_ptr.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr& operator= (const offset_ptr & ptr) BOOST_NOEXCEPT
- {
- this->internal.m_offset = ipcdetail::offset_ptr_to_offset_from_other(this, &ptr, ptr.internal.m_offset);
- return *this;
- }
- //!Assignment from related offset_ptr. If pointers of pointee types
- //! are assignable, offset_ptrs will be assignable. Never throws.
- template<class T2> BOOST_INTERPROCESS_FORCEINLINE
- #ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- typename ipcdetail::enable_if_c
- < ::boost::is_convertible<T2*, PointedType*>::value, offset_ptr&>::type
- #else
- offset_ptr&
- #endif
- operator= (const offset_ptr<T2, DifferenceType, OffsetType, OffsetAlignment> &ptr) BOOST_NOEXCEPT
- {
- this->assign(ptr, ipcdetail::bool_<ipcdetail::offset_ptr_maintains_address<T2, PointedType>::value>());
- return *this;
- }
- public:
- //!offset_ptr += difference_type.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr &operator+= (difference_type offset) BOOST_NOEXCEPT
- { this->inc_offset(offset * sizeof (PointedType)); return *this; }
- //!offset_ptr -= difference_type.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr &operator-= (difference_type offset) BOOST_NOEXCEPT
- { this->dec_offset(offset * sizeof (PointedType)); return *this; }
- //!++offset_ptr.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr& operator++ (void) BOOST_NOEXCEPT
- { this->inc_offset(sizeof (PointedType)); return *this; }
- //!offset_ptr++.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr operator++ (int) BOOST_NOEXCEPT
- {
- offset_ptr tmp(*this);
- this->inc_offset(sizeof (PointedType));
- return tmp;
- }
- //!--offset_ptr.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr& operator-- (void) BOOST_NOEXCEPT
- { this->dec_offset(sizeof (PointedType)); return *this; }
- //!offset_ptr--.
- //!Never throws.
- BOOST_INTERPROCESS_FORCEINLINE offset_ptr operator-- (int) BOOST_NOEXCEPT
- {
- offset_ptr tmp(*this);
- this->dec_offset(sizeof (PointedType));
- return tmp;
- }
- //!safe bool conversion operator.
- //!Never throws.
- #if defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS)
- BOOST_INTERPROCESS_FORCEINLINE operator unspecified_bool_type() const BOOST_NOEXCEPT
- { return this->internal.m_offset != 1? &self_t::unspecified_bool_type_func : 0; }
- #else
- explicit operator bool() const BOOST_NOEXCEPT
- { return this->internal.m_offset != 1; }
- #endif
-
- //!Not operator. Not needed in theory, but improves portability.
- //!Never throws
- BOOST_INTERPROCESS_FORCEINLINE bool operator! () const BOOST_NOEXCEPT
- { return this->internal.m_offset == 1; }
- //!Compatibility with pointer_traits
- //!
- #if defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
- template <class U>
- struct rebind
- { typedef offset_ptr<U, DifferenceType, OffsetType, OffsetAlignment> other; };
- #else
- template <class U>
- using rebind = offset_ptr<U, DifferenceType, OffsetType, OffsetAlignment>;
- #ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- typedef offset_ptr<PointedType, DifferenceType, OffsetType, OffsetAlignment> other;
- #endif //BOOST_INTERPROCESS_DOXYGEN_INVOKED
- #endif
- //!Compatibility with pointer_traits
- //!
- BOOST_INTERPROCESS_FORCEINLINE static offset_ptr pointer_to(reference r) BOOST_NOEXCEPT
- { return offset_ptr(&r); }
- //!difference_type + offset_ptr
- //!operation
- BOOST_INTERPROCESS_FORCEINLINE friend offset_ptr operator+(difference_type diff, offset_ptr right) BOOST_NOEXCEPT
- { right += diff; return right; }
- //!offset_ptr + difference_type
- //!operation
- BOOST_INTERPROCESS_FORCEINLINE friend offset_ptr operator+(offset_ptr left, difference_type diff) BOOST_NOEXCEPT
- { left += diff; return left; }
- //!offset_ptr - diff
- //!operation
- BOOST_INTERPROCESS_FORCEINLINE friend offset_ptr operator-(offset_ptr left, difference_type diff) BOOST_NOEXCEPT
- { left -= diff; return left; }
- //!offset_ptr - diff
- //!operation
- BOOST_INTERPROCESS_FORCEINLINE friend offset_ptr operator-(difference_type diff, offset_ptr right) BOOST_NOEXCEPT
- { right -= diff; return right; }
- //!offset_ptr - offset_ptr
- //!operation
- BOOST_INTERPROCESS_FORCEINLINE friend difference_type operator-(const offset_ptr &pt, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return difference_type(pt.get()- pt2.get()); }
- //Comparison
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator== (const offset_ptr &pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1.get() == pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator!= (const offset_ptr &pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1.get() != pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator<(const offset_ptr &pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1.get() < pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator<=(const offset_ptr &pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1.get() <= pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator>(const offset_ptr &pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1.get() > pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator>=(const offset_ptr &pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1.get() >= pt2.get(); }
- //Comparison to raw ptr to support literal 0
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator== (pointer pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1 == pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator!= (pointer pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1 != pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator<(pointer pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1 < pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator<=(pointer pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1 <= pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator>(pointer pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1 > pt2.get(); }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator>=(pointer pt1, const offset_ptr &pt2) BOOST_NOEXCEPT
- { return pt1 >= pt2.get(); }
- //Comparison
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator== (const offset_ptr &pt1, pointer pt2) BOOST_NOEXCEPT
- { return pt1.get() == pt2; }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator!= (const offset_ptr &pt1, pointer pt2) BOOST_NOEXCEPT
- { return pt1.get() != pt2; }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator<(const offset_ptr &pt1, pointer pt2) BOOST_NOEXCEPT
- { return pt1.get() < pt2; }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator<=(const offset_ptr &pt1, pointer pt2) BOOST_NOEXCEPT
- { return pt1.get() <= pt2; }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator>(const offset_ptr &pt1, pointer pt2) BOOST_NOEXCEPT
- { return pt1.get() > pt2; }
- BOOST_INTERPROCESS_FORCEINLINE friend bool operator>=(const offset_ptr &pt1, pointer pt2) BOOST_NOEXCEPT
- { return pt1.get() >= pt2; }
- BOOST_INTERPROCESS_FORCEINLINE friend void swap(offset_ptr &left, offset_ptr &right) BOOST_NOEXCEPT
- {
- pointer ptr = right.get();
- right = left;
- left = ptr;
- }
- private:
- template<class T2>
- BOOST_INTERPROCESS_FORCEINLINE void assign(const offset_ptr<T2, DifferenceType, OffsetType, OffsetAlignment> &ptr, ipcdetail::bool_<true>) BOOST_NOEXCEPT
- { //no need to pointer adjustment
- this->internal.m_offset = ipcdetail::offset_ptr_to_offset_from_other<OffsetType>(this, &ptr, ptr.get_offset());
- }
- template<class T2>
- BOOST_INTERPROCESS_FORCEINLINE void assign(const offset_ptr<T2, DifferenceType, OffsetType, OffsetAlignment> &ptr, ipcdetail::bool_<false>) BOOST_NOEXCEPT
- { //we must convert to raw before calculating the offset
- this->internal.m_offset = ipcdetail::offset_ptr_to_offset<OffsetType>(static_cast<PointedType*>(ptr.get()), this);
- }
- #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
- BOOST_INTERPROCESS_FORCEINLINE void inc_offset(DifferenceType bytes) BOOST_NOEXCEPT
- { internal.m_offset += bytes; }
- BOOST_INTERPROCESS_FORCEINLINE void dec_offset(DifferenceType bytes) BOOST_NOEXCEPT
- { internal.m_offset -= bytes; }
- ipcdetail::offset_ptr_internal<OffsetType, OffsetAlignment> internal;
- public:
- BOOST_INTERPROCESS_FORCEINLINE const OffsetType &priv_offset() const BOOST_NOEXCEPT
- { return internal.m_offset; }
- BOOST_INTERPROCESS_FORCEINLINE OffsetType &priv_offset() BOOST_NOEXCEPT
- { return internal.m_offset; }
- #endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- };
- //!operator<<
- //!for offset ptr
- template<class E, class T, class W, class X, class Y, std::size_t Z>
- inline std::basic_ostream<E, T> & operator<<
- (std::basic_ostream<E, T> & os, offset_ptr<W, X, Y, Z> const & p)
- { return os << p.get_offset(); }
- //!operator>>
- //!for offset ptr
- template<class E, class T, class W, class X, class Y, std::size_t Z>
- inline std::basic_istream<E, T> & operator>>
- (std::basic_istream<E, T> & is, offset_ptr<W, X, Y, Z> & p)
- { return is >> p.get_offset(); }
- //!Simulation of static_cast between pointers. Never throws.
- template<class T1, class P1, class O1, std::size_t A1, class T2, class P2, class O2, std::size_t A2>
- BOOST_INTERPROCESS_FORCEINLINE boost::interprocess::offset_ptr<T1, P1, O1, A1>
- static_pointer_cast(const boost::interprocess::offset_ptr<T2, P2, O2, A2> & r) BOOST_NOEXCEPT
- {
- return boost::interprocess::offset_ptr<T1, P1, O1, A1>
- (r, boost::interprocess::ipcdetail::static_cast_tag());
- }
- //!Simulation of const_cast between pointers. Never throws.
- template<class T1, class P1, class O1, std::size_t A1, class T2, class P2, class O2, std::size_t A2>
- BOOST_INTERPROCESS_FORCEINLINE boost::interprocess::offset_ptr<T1, P1, O1, A1>
- const_pointer_cast(const boost::interprocess::offset_ptr<T2, P2, O2, A2> & r) BOOST_NOEXCEPT
- {
- return boost::interprocess::offset_ptr<T1, P1, O1, A1>
- (r, boost::interprocess::ipcdetail::const_cast_tag());
- }
- //!Simulation of dynamic_cast between pointers. Never throws.
- template<class T1, class P1, class O1, std::size_t A1, class T2, class P2, class O2, std::size_t A2>
- BOOST_INTERPROCESS_FORCEINLINE boost::interprocess::offset_ptr<T1, P1, O1, A1>
- dynamic_pointer_cast(const boost::interprocess::offset_ptr<T2, P2, O2, A2> & r) BOOST_NOEXCEPT
- {
- return boost::interprocess::offset_ptr<T1, P1, O1, A1>
- (r, boost::interprocess::ipcdetail::dynamic_cast_tag());
- }
- //!Simulation of reinterpret_cast between pointers. Never throws.
- template<class T1, class P1, class O1, std::size_t A1, class T2, class P2, class O2, std::size_t A2>
- BOOST_INTERPROCESS_FORCEINLINE boost::interprocess::offset_ptr<T1, P1, O1, A1>
- reinterpret_pointer_cast(const boost::interprocess::offset_ptr<T2, P2, O2, A2> & r) BOOST_NOEXCEPT
- {
- return boost::interprocess::offset_ptr<T1, P1, O1, A1>
- (r, boost::interprocess::ipcdetail::reinterpret_cast_tag());
- }
- } //namespace interprocess {
- #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
- ///has_trivial_destructor<> == true_type specialization for optimizations
- template <class T, class P, class O, std::size_t A>
- struct has_trivial_destructor< ::boost::interprocess::offset_ptr<T, P, O, A> >
- {
- static const bool value = true;
- };
- namespace move_detail {
- ///has_trivial_destructor<> == true_type specialization for optimizations
- template <class T, class P, class O, std::size_t A>
- struct is_trivially_destructible< ::boost::interprocess::offset_ptr<T, P, O, A> >
- {
- static const bool value = true;
- };
- } //namespace move_detail {
- namespace interprocess {
- //!to_raw_pointer() enables boost::mem_fn to recognize offset_ptr.
- //!Never throws.
- template <class T, class P, class O, std::size_t A>
- BOOST_INTERPROCESS_FORCEINLINE T * to_raw_pointer(boost::interprocess::offset_ptr<T, P, O, A> const & p) BOOST_NOEXCEPT
- { return ipcdetail::to_raw_pointer(p); }
- } //namespace interprocess
- #endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- } //namespace boost {
- #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
- namespace boost{
- //This is to support embedding a bit in the pointer
- //for intrusive containers, saving space
- namespace intrusive {
- //Predeclaration to avoid including header
- template<class VoidPointer, std::size_t N>
- struct max_pointer_plus_bits;
- template<std::size_t OffsetAlignment, class P, class O, std::size_t A>
- struct max_pointer_plus_bits<boost::interprocess::offset_ptr<void, P, O, A>, OffsetAlignment>
- {
- //The offset ptr can embed one bit less than the alignment since it
- //uses offset == 1 to store the null pointer.
- static const std::size_t value = ::boost::interprocess::ipcdetail::ls_zeros<OffsetAlignment>::value - 1;
- };
- //Predeclaration
- template<class Pointer, std::size_t NumBits>
- struct pointer_plus_bits;
- template<class T, class P, class O, std::size_t A, std::size_t NumBits>
- struct pointer_plus_bits<boost::interprocess::offset_ptr<T, P, O, A>, NumBits>
- {
- typedef boost::interprocess::offset_ptr<T, P, O, A> pointer;
- //Bits are stored in the lower bits of the pointer except the LSB,
- //because this bit is used to represent the null pointer.
- static const O Mask = ((static_cast<O>(1) << NumBits) - static_cast<O>(1)) << 1;
- BOOST_STATIC_ASSERT(0 ==(Mask&1));
- //We must ALWAYS take argument "n" by reference as a copy of a null pointer
- //with a bit (e.g. offset == 3) would be incorrectly copied and interpreted as non-null.
- BOOST_INTERPROCESS_FORCEINLINE static pointer get_pointer(const pointer &n) BOOST_NOEXCEPT
- {
- pointer p;
- O const tmp_off = n.priv_offset() & ~Mask;
- p.priv_offset() = boost::interprocess::ipcdetail::offset_ptr_to_offset_from_other(&p, &n, tmp_off);
- return p;
- }
- BOOST_INTERPROCESS_FORCEINLINE static void set_pointer(pointer &n, const pointer &p) BOOST_NOEXCEPT
- {
- BOOST_ASSERT(0 == (get_bits)(p));
- O const stored_bits = n.priv_offset() & Mask;
- n = p;
- n.priv_offset() |= stored_bits;
- }
- BOOST_INTERPROCESS_FORCEINLINE static std::size_t get_bits(const pointer &n) BOOST_NOEXCEPT
- {
- return std::size_t((n.priv_offset() & Mask) >> 1u);
- }
- BOOST_INTERPROCESS_FORCEINLINE static void set_bits(pointer &n, std::size_t const b) BOOST_NOEXCEPT
- {
- BOOST_ASSERT(b < (std::size_t(1) << NumBits));
- O tmp = n.priv_offset();
- tmp &= ~Mask;
- tmp |= O(b << 1u);
- n.priv_offset() = tmp;
- }
- };
- } //namespace intrusive
- //Predeclaration
- template<class T, class U>
- struct pointer_to_other;
- //Backwards compatibility with pointer_to_other
- template <class PointedType, class DifferenceType, class OffsetType, std::size_t OffsetAlignment, class U>
- struct pointer_to_other
- < ::boost::interprocess::offset_ptr<PointedType, DifferenceType, OffsetType, OffsetAlignment>, U >
- {
- typedef ::boost::interprocess::offset_ptr<U, DifferenceType, OffsetType, OffsetAlignment> type;
- };
- } //namespace boost{
- #endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
- #include <boost/interprocess/detail/config_end.hpp>
- #endif //#ifndef BOOST_INTERPROCESS_OFFSET_PTR_HPP
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