From: Matt Corallo <git@bluematt.me>
Date: Sun, 18 Sep 2022 13:55:08 +0000 (+0000)
Subject: Avoid returning a reference to a u64.
X-Git-Tag: v0.0.112~33^2
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=refs%2Fheads%2F2022-09-slices-not-vecs;p=rust-lightning

Avoid returning a reference to a u64.

In c353c3ed7c40e689a3b9fb6730c6dabbd3c92cc5 an accessor method was
added which returns an `Option<&u64>`. While this allows Rust to
return an 8-byte object, returning a reference to something
pointer-sized is a somewhat strange API.

Instead, we opt for a straight `Option<u64>`, which is sadly
somewhat larger on the stack, but is simpler and already supported
in the bindings generation.
---

diff --git a/lightning-invoice/src/payment.rs b/lightning-invoice/src/payment.rs
index 226e8fe42..3b4fe7092 100644
--- a/lightning-invoice/src/payment.rs
+++ b/lightning-invoice/src/payment.rs
@@ -741,8 +741,8 @@ pub struct InFlightHtlcs(HashMap<(u64, bool), u64>);
 impl InFlightHtlcs {
 	/// Returns liquidity in msat given the public key of the HTLC source, target, and short channel
 	/// id.
-	pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<&u64> {
-		self.0.get(&(channel_scid, source < target))
+	pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<u64> {
+		self.0.get(&(channel_scid, source < target)).map(|v| *v)
 	}
 }