elliptic-curve: conditionally impl Invert for NonZeroScalar

...if the underlying scalar type it wraps also impls `Invert`

elliptic-curve/src/scalar.rs

@@ -1,6 +1,6 @@
 //! Scalar types
 
-use crate::{Arithmetic, Curve, ElementBytes, FromBytes};
+use crate::{ops::Invert, Arithmetic, Curve, ElementBytes, FromBytes};
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
 
 #[cfg(feature = "rand")]
@@ -84,6 +84,19 @@ where
  }
 }
 
+impl<C> Invert for NonZeroScalar<C>
+where
+ C: Curve + Arithmetic,
+ C::Scalar: Invert,
+{
+ type Output = <C::Scalar as Invert>::Output;
+
+ /// Perform a scalar inversion
+ fn invert(&self) -> CtOption<Self::Output> {
+ self.scalar.invert()
+ }
+}
+
 #[cfg(feature = "rand")]
 impl<C> Generate for NonZeroScalar<C>
 where