[Issue 7033] File.rawWrite is slow on Windows

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=7033

--- Comment #1 from Orvid King <blah38621 at gmail.com> ---
The reason for this is because rawWrite calls flush, not once, but twice every 
time you call it, on the underlying file. This is absolutely absurd, and is a 
massive performance bottleneck, especially when it's not needed because the 
file may very well have already been opened for writing in binary mode to begin 
with. In this particular example, it's flushing to disk every 3 bytes.

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