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From: "Jeffrey R. Carter" <jrcarter@acm.org>
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Newsgroups: comp.lang.ada
Subject: Re: Reading Float Data from a binary file into ada
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Date: 2007-02-01T00:05:23+00:00
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frikk wrote:
> 
> So my main question at this point is: How do I create the equivelant
> of this:
> union float_union
> {
>   float x;
>   unsigned char c[4];
> };

That's pretty simple. You put your input bytes into

subtype Raw_Bytes is System.Storage_Elements.Storage_Array (1 .. 4);

Raw : constant Raw_Bytes := Reorder (Get_Bytes (Raw_Bytes'Length) );

(Raw is in the proper order, of course). You define

function To_Float is new Ada.Unchecked_Conversion
    (Source => Raw_Bytes, Target => Interfaces.C.C_Float);

and then

Result : constant Interfaces.C.C_Float := To_Float (Raw);

You probably want that in some application-friendly type, though, so 
you'd really do something like

Result : constant My_Type := My_Type (To_Float (Raw) );

Finally

return Result;

This can end up being one of those functions where everything's done in 
the declarations.

-- 
Jeff Carter
"Alms for an ex-leper!"
Monty Python's Life of Brian
75