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Copy pathoffset_ptr.hpp
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879 lines (724 loc) · 33.8 KB
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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/move/detail/type_traits.hpp>
#include <boost/interprocess/interprocess_fwd.hpp>
#include <boost/interprocess/interprocess_printers.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>
#include <cstddef>
#if defined(BOOST_GCC) && (BOOST_GCC >= 40700)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#endif
//!\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)
#if !defined( BOOST_NO_CXX11_NULLPTR )
typedef decltype(nullptr) op_nullptr_t;
#else
struct op_nullptr_t
{
void* lx; //to achieve pointer alignment
struct nat {int bool_conversion;};
BOOST_INTERPROCESS_FORCEINLINE op_nullptr_t() {}
BOOST_INTERPROCESS_FORCEINLINE op_nullptr_t(int nat::*) {}
BOOST_INTERPROCESS_FORCEINLINE operator int nat::*() const { return 0; }
template <class T>
BOOST_INTERPROCESS_FORCEINLINE operator T*() const { return 0; }
template <class T, class U>
BOOST_INTERPROCESS_FORCEINLINE operator T U::* () const { return 0; }
friend BOOST_INTERPROCESS_FORCEINLINE bool operator==(op_nullptr_t, op_nullptr_t) { return true; }
friend BOOST_INTERPROCESS_FORCEINLINE bool operator!=(op_nullptr_t, op_nullptr_t) { return false; }
};
#endif
namespace ipcdetail {
//workarounds for void offset_ptrs
struct op_nat{};
template <class T> struct op_reference
: add_reference<T>
{};
template <> struct op_reference<void>
{ typedef op_nat type; };
template <> struct op_reference<void const>
{ typedef op_nat type; };
template <> struct op_reference<void volatile>
{ typedef op_nat type; };
template <> struct op_reference<void const volatile>
{ typedef op_nat type; };
template<class OffsetType, std::size_t OffsetAlignment>
union offset_ptr_internal
{
BOOST_INTERPROCESS_STATIC_ASSERT(sizeof(OffsetType) >= sizeof(uintptr_t));
BOOST_INTERPROCESS_STATIC_ASSERT(boost::move_detail::is_integral<OffsetType>::value && boost::move_detail::is_unsigned<OffsetType>::value);
BOOST_INTERPROCESS_FORCEINLINE 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::move_detail::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::move_detail::is_convertible<From*, To*>::value
&& !offset_ptr_maintains_address<From, To>::value
, Ret>
{};
template <class T, class P>
struct is_ptr_constructible;
template <class T, class P>
struct is_ptr_constructible<T*, P*>
{
private:
template<class U> static U get();
template <typename U>
static yes_type test( typename enable_if_c< sizeof( new U*(get<P*>()) ) != 0, int >::type );
template <typename U>
static no_type test(...);
public:
static const bool value = sizeof(test<T>(0)) == sizeof(yes_type);
};
} //namespace ipcdetail {
#endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
//!A smart pointer that stores the offset between the pointer and the
//!object it points to. This 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 at 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::
op_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 nullptr.
//!Never throws.
BOOST_INTERPROCESS_FORCEINLINE offset_ptr(op_nullptr_t) BOOST_NOEXCEPT
: internal(1)
{}
#if defined( BOOST_NO_CXX11_NULLPTR )
//!Constructor from nullptr. Some compilers (e.g. g++14) in C++03 mode have problems with op_nullptr_t
//!so a helper overload is needed. Never throws.
BOOST_INTERPROCESS_FORCEINLINE offset_ptr(int ipcdetail::op_nat::*) BOOST_NOEXCEPT
: internal(1)
{}
#endif //BOOST_NO_CXX11_NULLPTR
//!Constructor from raw pointer. Only takes part in overload resolution if T* is convertible to PointedType*
//!Never throws.
template <class T>
BOOST_INTERPROCESS_FORCEINLINE offset_ptr( T *ptr
#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
, typename ipcdetail::enable_if< ::boost::move_detail::is_convertible<T*, PointedType*> >::type * = 0
#endif
) 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))
{}
//!Constructor from other offset_ptr available so that static_cast<> works according to Allocator::pointer requirements:
//! static_cast<pointer>(void_pointer()) + static_cast<const_pointer>(const_void_pointer())
//!Discouraged for any other conversion, static_pointer_cast is the way for downcasts and other static_cast-like conversions.
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< ipcdetail::is_cv_same<T2, void>::value && //Allow only void to something casts for static_cast
!::boost::move_detail::is_convertible<T2*, PointedType*>::value &&
ipcdetail::is_ptr_constructible<T2*, PointedType*>::value
>::type * = 0
#endif
) BOOST_NOEXCEPT //void -> T conversion is address-preserving, so take advantage of that
: internal(ipcdetail::offset_ptr_to_offset_from_other(this, &ptr, ptr.get_offset()))
{}
#endif
//!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 raw pointer. Only takes part in overload resolution if T* is convertible to PointedType*
//!Never throws.
template<class T> BOOST_INTERPROCESS_FORCEINLINE
#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
typename ipcdetail::enable_if_c
< ::boost::move_detail::is_convertible<T*, PointedType*>::value, offset_ptr&>::type
#else
offset_ptr&
#endif
operator= (T *ptr) BOOST_NOEXCEPT
{
this->internal.m_offset = ipcdetail::offset_ptr_to_offset<OffsetType>(static_cast<PointedType*>(ptr), 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 nullptr.
//!Never throws.
BOOST_INTERPROCESS_FORCEINLINE offset_ptr& operator= (op_nullptr_t) BOOST_NOEXCEPT
{
this->internal.m_offset = 1;
return *this;
}
#if defined( BOOST_NO_CXX11_NULLPTR )
//!Assignment from nullptr. Some compilers (e.g. g++14) in C++03 mode have problems with op_nullptr_t
//!so a helper overload is needed. Never throws.
BOOST_INTERPROCESS_FORCEINLINE offset_ptr& operator= (int ipcdetail::op_nat::*) BOOST_NOEXCEPT
{
this->internal.m_offset = 1;
return *this;
}
#endif //BOOST_NO_CXX11_NULLPTR
//!Assignment from related offset_ptr.
//!Only takes part in overload resolution if T2* is convertible to PointedType*
//!Never throws.
template<class T2> BOOST_INTERPROCESS_FORCEINLINE
#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
typename ipcdetail::enable_if_c
< ::boost::move_detail::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 * difference_type(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 * difference_type(sizeof(PointedType))); return *this; }
//!++offset_ptr.
//!Never throws.
BOOST_INTERPROCESS_FORCEINLINE offset_ptr& operator++ (void) BOOST_NOEXCEPT
{ this->inc_offset(difference_type(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(typename ipcdetail::op_reference<PointedType>::type 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 += OffsetType(bytes); }
BOOST_INTERPROCESS_FORCEINLINE void dec_offset(DifferenceType bytes) BOOST_NOEXCEPT
{ internal.m_offset -= OffsetType(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 P, class O, std::size_t A, class T2>
BOOST_INTERPROCESS_FORCEINLINE boost::interprocess::offset_ptr<T1, P, O, A>
static_pointer_cast(const boost::interprocess::offset_ptr<T2, P, O, A> & r) BOOST_NOEXCEPT
{
return boost::interprocess::offset_ptr<T1, P, O, A>
(r, boost::interprocess::ipcdetail::static_cast_tag());
}
//!Simulation of const_cast between pointers. Never throws.
template<class T1, class P, class O, std::size_t A, class T2>
BOOST_INTERPROCESS_FORCEINLINE boost::interprocess::offset_ptr<T1, P, O, A>
const_pointer_cast(const boost::interprocess::offset_ptr<T2, P, O, A> & r) BOOST_NOEXCEPT
{
return boost::interprocess::offset_ptr<T1, P, O, A>
(r, boost::interprocess::ipcdetail::const_cast_tag());
}
//!Simulation of dynamic_cast between pointers. Never throws.
template<class T1, class P, class O, std::size_t A, class T2>
BOOST_INTERPROCESS_FORCEINLINE boost::interprocess::offset_ptr<T1, P, O, A>
dynamic_pointer_cast(const boost::interprocess::offset_ptr<T2, P, O, A> & r) BOOST_NOEXCEPT
{
return boost::interprocess::offset_ptr<T1, P, O, A>
(r, boost::interprocess::ipcdetail::dynamic_cast_tag());
}
//!Simulation of reinterpret_cast between pointers. Never throws.
template<class T1, class P, class O, std::size_t A, class T2>
BOOST_INTERPROCESS_FORCEINLINE boost::interprocess::offset_ptr<T1, P, O, A>
reinterpret_pointer_cast(const boost::interprocess::offset_ptr<T2, P, O, A> & r) BOOST_NOEXCEPT
{
return boost::interprocess::offset_ptr<T1, P, O, A>
(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_INTERPROCESS_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>
#if defined(BOOST_GCC) && (BOOST_GCC >= 40700)
#pragma GCC diagnostic pop
#endif
#endif //#ifndef BOOST_INTERPROCESS_OFFSET_PTR_HPP
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