The following example from http://www.digitalmars.com/d/2.0/phobos/std_stream.html does not seem to compile with the latest D compiler:

	Stream file = new BufferedFile("sample.txt");
	foreach(ulong n, string line; file) {
	  stdout.writefln("line %d: %s",n,line);
	}
	file.close();

The error is due to the D 2.0 string/invariance changes (which I'm still trying to wrap my head around; is there a good reference that sorts it all out?) [*]

The most literal, valid translation of the above code that I can manage is as follows:

	Stream file = new BufferedFile("sample.txt");
	foreach(ulong n, char[] char_ar; file)
	{
		string line = char_ar.idup;
		writefln("line %d: %s",n,line);
	}
	file.close();

although for this particular example, you could just replace string with char[]. The problem with that approach is that you usually want a string at some point, so you can do all the wonderful string operations that one tends to do.

Is this just a case where the Stream library just hasn't been string-invariance-ized yet? Or is there a different way to do things now? (In which case I recommend updating the documentation!)

	Michael







[*] It's worth noting that there's also an error with 'stdout.writefln' hence my replacement with 'writefln' in the second block of code.

This one bugs me as well. The reason is that opApply uses readLine, which in turn calls readLine(char[]), reusing the passed buffer. This will never return an invariant string, and the result must therefor always be idup'ed :-((

I don't think there's anything that can be done to 'fix' this. readLine must write to the buffer, so it's never invariant. Casting to invariant is not possible, as it would break all the guarantees. I wonder if there's something that can be done by using an "invariant constructor" mentioned in Andrei's PDF (see Walter's post in the other group.)

L.