Worlds smallest optimization

Preallocate for 8 items in the vec. I chose this value for

1. features
2. description
3. payment hash
4. expire time
5. min_final_cltv
6. payment secret
7. route hint
8. for the memes

diff --git a/lightning-invoice/src/lib.rs b/lightning-invoice/src/lib.rs
index df0412bfc5d3e0d3876b177200527e01fd272678..610f739e57ad9d294610103edd36bbd5155d7109 100644 (file)
--- a/lightning-invoice/src/lib.rs
+++ b/lightning-invoice/src/lib.rs
@@ -550,7 +550,7 @@ impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False, tb::False, tb::F
                        amount: None,
                        si_prefix: None,
                        timestamp: None,
-                       tagged_fields: Vec::new(),
+                       tagged_fields: Vec::with_capacity(8),
                        error: None,
 
                        phantom_d: core::marker::PhantomData,