On Tue, 21 Sep 2010 19:06:43 -0400, Jonathan M Davis <jmdavisp...@gmx.com>
wrote:
Okay, it seems that the way to read in a binary file is to use
std.file.read()
which reads in the file as a void[]. This immediately raises the
question as to
how to convert the void[] into something useful. It seems to me that
casting
void[] to a ubyte[] is then the appropriate thing to do because then
you can
properly index it and grab the appropriate bytes that need to be
converting into
useful values. However, that still raises the question of how to get
anything
useful out of the bytes. UTF-8 strings are easy because they're the same
size as
ubytes. Casting to char[] for the portion of the data that you want as a
string
seems to work just fine. But what about other types? Is it the correct
thing to
cast to T[] where T is whatever type the data represents and then index
into it
to get the values that you want of that type and then cast the next
section of
the data to U[] where U is the type for the next section of the data,
etc.? Or
is there a better way to handle this?
You can slice void arrays, even though you cannot index them. If you know
for instance that a struct S resides at the 15th byte, you can do:
(cast(S[])arr[15..$])[0];
or:
*(cast(S*)arr.ptr + 15);
there are various ways to get the data. Only if you know the data is an
*array* of a certain type is it useful to cast the entire array.
-Steve
