The analogue of "fill-pointer" in D

[Kagamin via Digitalmars-d-learn]

On Monday, 18 May 2015 at 10:24:25 UTC, Dennis Ritchie wrote:
> It seems to be nonsense. But this is nonsense, ideal for 
> buffers. If the buffer is implemented as an array, then fill 
> pointer just marks the boundary of the filled part of the 
> buffer, and adding a buffer (moving away from the fill 
> pointer-a) is carried out using the vector-push. Or a buffer 
> can be filled with the format-a. If you work with the same 
> buffer C, fill pointer simulates a pointer to the last 
> completed item."

Filling a buffer is usually done this way: 
http://dlang.org/phobos/std_stdio.html#.File.rawRead