From 0dbbef209489e25bc0e2f9749e92c306ffb045ab Mon Sep 17 00:00:00 2001
From: Adam Ierymenko <adam.ierymenko@zerotier.com>
Date: Mon, 20 Nov 2023 10:21:06 -0500
Subject: [PATCH] Add is_default()

---
 src/lib.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index 572d722..da6cb26 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -95,6 +95,14 @@ pub fn slice_is_empty<T>(s: &[T]) -> bool {
     s.is_empty()
 }
 
+/// Checks if a value is equal to its default.
+/// This could be inefficient if default() is non-trivial. Should be used for things like
+/// eliding serialization of zeroes and other default values with serde.
+#[inline(always)]
+pub fn is_default<V: Default + PartialEq>(v: &V) -> bool {
+    V::default().eq(v)
+}
+
 #[cold]
 #[inline(never)]
 pub extern "C" fn unlikely_branch() {}