What is the std.stream replacement?

[Charles Hixson via Digitalmars-d-learn]

I have DMD64 D Compiler v2.067.1 installed, and in the documentation of 
phobos what it says about std.stream is "don't use it on new code".  It 
doesn't, however, appear to offer any replacement. Certainly std.file, 
std.stdio, and std.path aren't replacements.

So what *is* the appropriate replacement?  More specificly, what should 
one use for binary i/o, particularly random access binary i/o?  With 
fixed block size.