add dyn cast to sbp

sbp/src/operators.rs

@@ -72,11 +72,13 @@ impl<SBP: SbpOperator1d + Copy> SbpOperator2d for SBP {
 
 pub trait UpwindOperator1d: SbpOperator1d + Send + Sync {
     fn diss(&self, prev: ArrayView1<Float>, fut: ArrayViewMut1<Float>);
+    fn as_sbp(&self) -> &dyn SbpOperator1d;
 }
 
 pub trait UpwindOperator2d: SbpOperator2d + Send + Sync {
     fn dissxi(&self, prev: ArrayView2<Float>, fut: ArrayViewMut2<Float>);
     fn disseta(&self, prev: ArrayView2<Float>, fut: ArrayViewMut2<Float>);
+    fn as_sbp(&self) -> &dyn SbpOperator2d;
 }
 
 impl<UOeta: UpwindOperator1d, UOxi: UpwindOperator1d> UpwindOperator2d for (&UOeta, &UOxi) {
@@ -90,6 +92,9 @@ impl<UOeta: UpwindOperator1d, UOxi: UpwindOperator1d> UpwindOperator2d for (&UOe
         let ba = (self.1, self.0);
         ba.dissxi(prev.reversed_axes(), fut.reversed_axes())
     }
+    fn as_sbp(&self) -> &dyn SbpOperator2d {
+        self
+    }
 }
 
 impl<UO: UpwindOperator1d + Copy> UpwindOperator2d for UO {
@@ -99,6 +104,9 @@ impl<UO: UpwindOperator1d + Copy> UpwindOperator2d for UO {
     fn disseta(&self, prev: ArrayView2<Float>, fut: ArrayViewMut2<Float>) {
         <(&UO, &UO) as UpwindOperator2d>::disseta(&(self, self), prev, fut)
     }
+    fn as_sbp(&self) -> &dyn SbpOperator2d {
+        self
+    }
 }
 
 pub trait InterpolationOperator: Send + Sync {

sbp/src/operators/upwind4.rs

@@ -413,6 +413,10 @@ impl UpwindOperator1d for Upwind4 {
             fut,
         )
     }
+
+    fn as_sbp(&self) -> &dyn SbpOperator1d {
+        self
+    }
 }
 
 impl<SBP: UpwindOperator1d> UpwindOperator2d for (&Upwind4, &SBP) {

sbp/src/operators/upwind4h2.rs

@@ -92,4 +92,8 @@ impl UpwindOperator1d for Upwind4h2 {
             fut,
         )
     }
+
+    fn as_sbp(&self) -> &dyn SbpOperator1d {
+        self
+    }
 }

sbp/src/operators/upwind9.rs

@@ -72,6 +72,10 @@ impl UpwindOperator1d for Upwind9 {
             fut,
         )
     }
+
+    fn as_sbp(&self) -> &dyn SbpOperator1d {
+        self
+    }
 }
 
 #[test]

sbp/src/operators/upwind9h2.rs

@@ -100,4 +100,7 @@ impl UpwindOperator1d for Upwind9h2 {
             fut,
         )
     }
+    fn as_sbp(&self) -> &dyn SbpOperator1d {
+        self
+    }
 }