From 35d82ab87290619cd0805a4cad7a25b1473e018b Mon Sep 17 00:00:00 2001
From: Colin Rofls <colin@cmyr.net>
Date: Thu, 23 Nov 2023 12:06:04 -0500
Subject: [PATCH] [write-fonts] Add VariationStoreBuilder::is_empty

I need this in fea-rs
---
 write-fonts/src/tables/variations/ivs_builder.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/write-fonts/src/tables/variations/ivs_builder.rs b/write-fonts/src/tables/variations/ivs_builder.rs
index 6846d8f9c..0e36e136c 100644
--- a/write-fonts/src/tables/variations/ivs_builder.rs
+++ b/write-fonts/src/tables/variations/ivs_builder.rs
@@ -74,6 +74,14 @@ impl VariationStoreBuilder {
         Default::default()
     }
 
+    /// Returns `true` if no deltas have been added to this builder
+    pub fn is_empty(&self) -> bool {
+        match &self.delta_sets {
+            DeltaSetStorage::Direct(val) => val.is_empty(),
+            DeltaSetStorage::Deduplicated(val) => val.is_empty(),
+        }
+    }
+
     /// Create a builder that does not share deltas between entries.
     ///
     /// This is used in HVAR, where it is possible to use glyph ids as the