From 6542a6cb566557b0e47e962815525bbecb9ba2ae Mon Sep 17 00:00:00 2001
From: Daniel Dulaney <dulaney.daniel@gmail.com>
Date: Tue, 13 Jul 2021 11:31:11 -0400
Subject: [PATCH 1/2] Enable creating a const TimeSpec

Previously, there was no way to create a TimeSpec in a const context
because all creation was through traits. This adds two utility
functions to create a const TimeSpec from a libc::timespec or a
std::time::Duration
---
 src/sys/time.rs | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/sys/time.rs b/src/sys/time.rs
index 7546d1b367..c786500a3c 100644
--- a/src/sys/time.rs
+++ b/src/sys/time.rs
@@ -77,11 +77,7 @@ impl From<timespec> for TimeSpec {
 
 impl From<Duration> for TimeSpec {
     fn from(duration: Duration) -> Self {
-        #[cfg_attr(target_env = "musl", allow(deprecated))] // https://github.com/rust-lang/libc/issues/1848
-        TimeSpec(timespec {
-            tv_sec: duration.as_secs() as time_t,
-            tv_nsec: duration.subsec_nanos() as timespec_tv_nsec_t
-        })
+        Self::from_duration(duration)
     }
 }
 
@@ -198,6 +194,18 @@ impl TimeSpec {
     pub fn tv_nsec(&self) -> timespec_tv_nsec_t {
         self.0.tv_nsec
     }
+
+    pub const fn from_duration(duration: Duration) -> Self {
+        #[cfg_attr(target_env = "musl", allow(deprecated))] // https://github.com/rust-lang/libc/issues/1848
+        TimeSpec(timespec {
+            tv_sec: duration.as_secs() as time_t,
+            tv_nsec: duration.subsec_nanos() as timespec_tv_nsec_t
+        })
+    }
+
+    pub const fn from_timespec(timespec: timespec) -> Self {
+        Self(timespec)
+    }
 }
 
 impl ops::Neg for TimeSpec {

From 7de40a921a493643727709596d14c2f2187166b8 Mon Sep 17 00:00:00 2001
From: Daniel Dulaney <dulaney.daniel@gmail.com>
Date: Wed, 14 Jul 2021 01:29:51 -0400
Subject: [PATCH 2/2] Update changelog with TimeSpec additions

---
 CHANGELOG.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 21cb4b85a2..9ddef3680e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,9 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased] - ReleaseDate
 ### Added
+- Added `TimeSpec::from_duration` and `TimeSpec::from_timespec`
+  (#[1465](https://github.com/nix-rust/nix/pull/1465))
+
 ### Changed
 ### Fixed
 ### Removed