Merge pull request #816 from dusk-network/mocello/815_default_witness

Add `Default` trait implementation for `Witness`

Author: moCello

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Reduce hades constants count in circuit compression from 960 to 335 [#813]
 
+### Added
+
+- Add `Default` trait for `Witness` [#815]
+
 ## [0.19.0] - 2024-01-03
 
 ### Fixed
@@ -567,6 +571,7 @@ is necessary since `rkyv/validation` was required as a bound.
 - Proof system module.
 
 <!-- ISSUES -->
+[#815]: https://github.com/dusk-network/plonk/issues/815
 [#813]: https://github.com/dusk-network/plonk/issues/813
 [#805]: https://github.com/dusk-network/plonk/issues/805
 [#804]: https://github.com/dusk-network/plonk/issues/804

src/composer/constraint_system/witness.rs

@@ -29,6 +29,12 @@ pub struct Witness {
     index: usize,
 }
 
+impl Default for Witness {
+    fn default() -> Self {
+        crate::composer::Composer::ZERO
+    }
+}
+
 impl Witness {
     /// A `0` witness representation.
     pub const ZERO: Witness = Witness::new(0);