Support setting file accessed/modified timestamps

Add `struct FileTimes` to contain the relevant file timestamps, since
most platforms require setting all of them at once. (This also allows
for future platform-specific extensions such as setting creation time.)

Add `File::set_file_time` to set the timestamps for a `File`.

Implement the `sys` backends for UNIX, macOS (which needs to fall back
to `futimes` before macOS 10.13 because it lacks `futimens`), Windows,
and WASI.

1 files changed, 7 insertions, 1 deletions

diff --git a/library/std/src/time.rs b/library/std/src/time.rs
index b2014f462bd..759a59e1f98 100644
--- a/library/std/src/time.rs
+++ b/library/std/src/time.rs
@@ -38,7 +38,7 @@ use crate::error::Error;
 use crate::fmt;
 use crate::ops::{Add, AddAssign, Sub, SubAssign};
 use crate::sys::time;
-use crate::sys_common::FromInner;
+use crate::sys_common::{FromInner, IntoInner};
 
 #[stable(feature = "time", since = "1.3.0")]
 pub use core::time::Duration;
@@ -686,3 +686,9 @@ impl FromInner<time::SystemTime> for SystemTime {
         SystemTime(time)
     }
 }
+
+impl IntoInner<time::SystemTime> for SystemTime {
+    fn into_inner(self) -> time::SystemTime {
+        self.0
+    }
+}