Searching for a string in a text buffer with a regular expression

[maxpat78]

While porting a simple Python script to D, I found the following 
problem.

I need to read in some thousand of little text files and search 
every one for a match with a given regular expression.

Obviously, the program can't (and it should not) be certain about 
the encoding of each input file.

I initially used read() casting it with a cast(char[]), but, at 
some point, the regex engine crashed with an exception: it 
encountered an UTF-8 character it couldn't automatically decode. 
This is right, since char[] is not byte[].

Now I'm casting with a Latin1String, since I know this is the 
right encoding for the input buffers: and it works fine, at 
last... but what about if I'd need to treat a RAW (binary? 
unknown encoding?) buffer?

Is there a simple and elegant solution in D for such case?
Python didn't gave such problems!