From 39e1c2818944f804d68d64dae0d5639d22b0e59e Mon Sep 17 00:00:00 2001
From: FuseTim <fusetim@gmx.com>
Date: Sun, 11 Jul 2021 16:09:17 +0200
Subject: [PATCH] Adding missing methods to Instant, matching Rust 1.39

---
 src/wasm.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/wasm.rs b/src/wasm.rs
index 57ee1e6..596b345 100644
--- a/src/wasm.rs
+++ b/src/wasm.rs
@@ -70,6 +70,25 @@ impl Instant {
     pub fn elapsed(&self) -> Duration {
         Instant::now() - *self
     }
+
+    pub fn checked_duration_since(&self, earlier: Instant) -> Option<Duration> {
+        match self.cmp(&earlier) {
+            Ordering::Less => None,
+            _ => Some(self.duration_since(earlier)),
+        }
+    }
+
+    pub fn saturating_duration_since(&self, earlier: Instant) -> Duration {
+        self.checked_duration_since(earlier).unwrap_or_default()
+    }
+
+    pub fn checked_add(&self, duration: Duration) -> Option<Instant> {
+        Some(*self + duration)
+    }
+
+    pub fn checked_sub(&self, duration: Duration) -> Option<Instant> {
+        Some(*self - duration)
+    }
 }
 
 impl Add<Duration> for Instant {