From 291b6f16bb03c92fb383dfa12b8849808bace801 Mon Sep 17 00:00:00 2001
From: Tobias Bucher <tobiasbucher5991@gmail.com>
Date: Mon, 18 Jul 2016 14:31:26 +0200
Subject: Comment on the casts in the `seek` implementations on files

---
 src/libstd/sys/windows/fs.rs | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'src/libstd/sys/windows')

diff --git a/src/libstd/sys/windows/fs.rs b/src/libstd/sys/windows/fs.rs
index 2683e57256d..4e6cef9a28d 100644
--- a/src/libstd/sys/windows/fs.rs
+++ b/src/libstd/sys/windows/fs.rs
@@ -324,6 +324,8 @@ impl File {
 
     pub fn seek(&self, pos: SeekFrom) -> io::Result<u64> {
         let (whence, pos) = match pos {
+            // Casting to `i64` is fine, `SetFilePointerEx` reinterprets this
+            // integer as `u64`.
             SeekFrom::Start(n) => (c::FILE_BEGIN, n as i64),
             SeekFrom::End(n) => (c::FILE_END, n),
             SeekFrom::Current(n) => (c::FILE_CURRENT, n),
-- 
cgit 1.4.1-3-g733a5