diff -r 212f75931da0 -r f75bf34adda0 src/mapping.rs
--- a/src/mapping.rs	Thu May 08 22:53:31 2025 -0500
+++ b/src/mapping.rs	Sun May 11 02:03:45 2025 -0500
@@ -3,12 +3,12 @@
 */
 
 use crate::error::DynResult;
+use crate::instance::MyCow;
 pub use crate::instance::{BasicDecomposition, Decomposition, Instance, Space};
 use crate::loc::Loc;
 use crate::norms::{Norm, NormExponent};
 use crate::operator_arithmetic::{Constant, Weighted};
 use crate::types::{ClosedMul, Float, Num};
-use std::borrow::Cow;
 use std::marker::PhantomData;
 use std::ops::Mul;
 
@@ -124,7 +124,7 @@
 impl<T, Domain> DifferentiableMapping<Domain> for T
 where
     Domain: Space,
-    T: Clone + Mapping<Domain> + DifferentiableImpl<Domain>,
+    T: Mapping<Domain> + DifferentiableImpl<Domain>,
 {
     type DerivativeDomain = T::Derivative;
     type Differential<'b>
@@ -139,26 +139,26 @@
 
     fn diff(self) -> Differential<'static, Domain, Self> {
         Differential {
-            g: Cow::Owned(self),
+            g: MyCow::Owned(self),
             _space: PhantomData,
         }
     }
 
     fn diff_ref(&self) -> Differential<'_, Domain, Self> {
         Differential {
-            g: Cow::Borrowed(self),
+            g: MyCow::Borrowed(self),
             _space: PhantomData,
         }
     }
 }
 
 /// Container for the differential [`Mapping`] of a [`DifferentiableMapping`].
-pub struct Differential<'a, X, G: Clone> {
-    g: Cow<'a, G>,
+pub struct Differential<'a, X, G> {
+    g: MyCow<'a, G>,
     _space: PhantomData<X>,
 }
 
-impl<'a, X, G: Clone> Differential<'a, X, G> {
+impl<'a, X, G> Differential<'a, X, G> {
     pub fn base_fn(&self) -> &G {
         &self.g
     }
@@ -167,7 +167,7 @@
 impl<'a, X, G> Mapping<X> for Differential<'a, X, G>
 where
     X: Space,
-    G: Clone + DifferentiableMapping<X>,
+    G: DifferentiableMapping<X>,
 {
     type Codomain = G::DerivativeDomain;
 
@@ -211,8 +211,8 @@
 impl<X: Space, F, G: Sized + Mapping<X, Codomain = Loc<1, F>>> FlattenCodomain<X, F> for G {}
 
 /// Container for dimensional slicing [`Loc`]`<N, F>` codomain of a [`Mapping`] to `F`.
-pub struct SlicedCodomain<'a, X, F, G: Clone, const N: usize> {
-    g: Cow<'a, G>,
+pub struct SlicedCodomain<'a, X, F, G, const N: usize> {
+    g: MyCow<'a, G>,
     slice: usize,
     _phantoms: PhantomData<(X, F)>,
 }
@@ -221,7 +221,7 @@
 where
     X: Space,
     F: Copy + Space,
-    G: Mapping<X, Codomain = Loc<N, F>> + Clone,
+    G: Mapping<X, Codomain = Loc<N, F>>,
 {
     type Codomain = F;
 
@@ -236,13 +236,13 @@
 /// An auto-trait for constructing a [`FlattenCodomain`] structure for
 /// flattening the codomain of a [`Mapping`] from [`Loc`]`<F, 1>` to `F`.
 pub trait SliceCodomain<X: Space, const N: usize, F: Copy = f64>:
-    Mapping<X, Codomain = Loc<N, F>> + Clone + Sized
+    Mapping<X, Codomain = Loc<N, F>> + Sized
 {
     /// Flatten the codomain from [`Loc`]`<F, 1>` to `F`.
     fn slice_codomain(self, slice: usize) -> SlicedCodomain<'static, X, F, Self, N> {
         assert!(slice < N);
         SlicedCodomain {
-            g: Cow::Owned(self),
+            g: MyCow::Owned(self),
             slice,
             _phantoms: PhantomData,
         }
@@ -252,14 +252,14 @@
     fn slice_codomain_ref(&self, slice: usize) -> SlicedCodomain<'_, X, F, Self, N> {
         assert!(slice < N);
         SlicedCodomain {
-            g: Cow::Borrowed(self),
+            g: MyCow::Borrowed(self),
             slice,
             _phantoms: PhantomData,
         }
     }
 }
 
-impl<X: Space, F: Copy, G: Sized + Mapping<X, Codomain = Loc<N, F>> + Clone, const N: usize>
+impl<X: Space, F: Copy, G: Sized + Mapping<X, Codomain = Loc<N, F>>, const N: usize>
     SliceCodomain<X, N, F> for G
 {
 }
@@ -337,7 +337,7 @@
 impl<'b, M, X, A> Lipschitz<M> for Differential<'b, X, A>
 where
     X: Space,
-    A: LipschitzDifferentiableImpl<X, M> + Clone,
+    A: LipschitzDifferentiableImpl<X, M>,
 {
     type FloatType = A::FloatType;