Re: [Boost-bugs] [Boost C++ Libraries] #10432: 32-bit offset_ptr crashes on 64-bit platform

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #10432: 32-bit offset_ptr crashes on 64-bit platform
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-09-17 20:02:48

#10432: 32-bit offset_ptr crashes on 64-bit platform
-------------------------------+--------------------------
  Reporter:  andysem           |      Owner:  igaztanaga
      Type:  Bugs              |     Status:  new
 Milestone:  To Be Determined  |  Component:  interprocess
   Version:  Boost 1.56.0      |   Severity:  Problem
Resolution:                    |   Keywords:  offset_ptr
-------------------------------+--------------------------

Comment (by igaztanaga):

 Using signed integers is problematic because overflow is undefined
 behaviour, there were problems with some compilers. And yes, offset_ptr
 was not thought to be used with integers smaller than size_t (or more
 strictly, smaller than uintptr_t). The option to customize the OffsetType
 was to allow interoperability between 32 and 64 bit applications using 64
 bit offset types.

 Many times, in a 64 bit OS, a 32 bit offset type can't hold the distance
 between a stack variable and a shared memory address, as the OS can place
 them further than 4GB.

 This is not documented and it should be explained.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10432#comment:1>
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