Re: Ada equivalent for C-pointer?

[Stephen Leake <stephen_leake@acm.org>]

Keith Thompson <kst-u@mib.org> writes:

> Alfred Hilscher <SPAM@alfred-hilscher.de> writes:
> > I want to interface to a C-function expecting a "far *", what have I to
> > pass: an "access all ..." or "System.Address"? Are there differences
> > between access and address, or are their internal representations equal?
> > I use GNAT 3.15p.
> 
> "far" pointers are an old Microsoft kludge.  The C standard doesn't
> define "far" pointers, and an Ada compiler's interface to C likely
> doesn't either.

To be somewhat more helpful:

On older x86 systems, when 16 bit operating systems were used, there
were two kinds of pointers; "near" pointers, 16 bits in size, and
"far" pointers, 32 or 48 bits in size.

These days, you should interpret "far" as a noop, and just think of it
as a pointer.

Whether it is 16, 32, or 64 bits depends on what machine, OS, and
compiler you are using.

-- 
-- Stephe