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From: Greg Baker <gbaker@walleroo.rp.csiro.au>
Subject: How to supply pointer to C?
Date: 1996/08/27
Message-ID: <85ybj1zcdu.fsf@walleroo.rp.CSIRO.AU>#1/1
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sender: usenet@rp.CSIRO.AU (Network news)
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organization: CSIRO Division of Radiophysics/Australia Telescope National
 Facility
newsgroups: comp.lang.ada
Date: 1996-08-27T00:00:00+00:00
List-Id: <comp.lang.ada>


Interfaces.C.Pointers.Value can get you from a C array to an Ada
array,  and Interfaces.C.To_C can get you from a String to a
null-terminated block of chars,  but what if I want to get a block of
ints,  for examples?

More generally, what if I have some object and I want to pass its
address to some C function.  (The question arises as I am trying to
write an Ada gdbm interface - gdbm_store takes as arguments structs of
the form-
  struct { char * dptr;   int data_size; }.
(i.e. record 
         dptr : Interfaces.C.Pointers.???
         data_size : Interfaces.C.int
      end;
)

I'm kind of hoping to do something like

  x.dptr := Magical_Conversion_function ( object'Access ); 
  x.data_size = object'Size;

Any suggestions?

-- 
Gregory D. Baker        gbaker@rp.csiro.au         CSIRO Radiophysics 
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