From 1db4b723dc59568c14c76598e7c63c58651ed1cd Mon Sep 17 00:00:00 2001
From: yancy <yancy@yancy.lol>
Date: Tue, 12 Nov 2024 12:54:45 -0600
Subject: [PATCH] Mark function as const

---
 units/src/weight.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/units/src/weight.rs b/units/src/weight.rs
index b43d76341..351dfd646 100644
--- a/units/src/weight.rs
+++ b/units/src/weight.rs
@@ -55,8 +55,12 @@ impl Weight {
     pub fn from_kwu(wu: u64) -> Option<Self> { wu.checked_mul(1000).map(Weight) }
 
     /// Constructs a new [`Weight`] from virtual bytes, returning [`None`] if an overflow occurred.
-    pub fn from_vb(vb: u64) -> Option<Self> {
-        vb.checked_mul(Self::WITNESS_SCALE_FACTOR).map(Weight::from_wu)
+    pub const fn from_vb(vb: u64) -> Option<Self> {
+        // No `map()` in const context.
+        match vb.checked_mul(Self::WITNESS_SCALE_FACTOR) {
+            Some(wu) => Some(Weight::from_wu(wu)),
+            None => None,
+        }
     }
 
     /// Constructs a new [`Weight`] from virtual bytes panicking if an overflow occurred.