Prevent write access to faces of Shape

src/kernel/shape/faces.rs

@@ -10,12 +10,11 @@ use super::{
 };
 
 /// The faces of a shape
-#[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
-pub struct Faces {
-    pub(super) faces: FacesInner,
+pub struct Faces<'r> {
+    pub(super) faces: &'r mut FacesInner,
 }
 
-impl Faces {
+impl Faces<'_> {
     /// Add a face to the shape
     pub fn add(&mut self, face: Face) -> Handle<Face> {
         self.faces.push(face.clone());
@@ -39,7 +38,7 @@ impl Faces {
         out: &mut Vec<Triangle<3>>,
         debug_info: &mut DebugInfo,
     ) {
-        for face in &self.faces {
+        for face in &*self.faces {
             face.triangles(tolerance, out, debug_info);
         }
     }

src/kernel/shape/mod.rs

@@ -29,7 +29,7 @@ pub struct Shape {
 
     vertices: VerticesInner,
     cycles: CyclesInner,
-    faces: Faces,
+    faces: FacesInner,
 }
 
 impl Shape {
@@ -43,7 +43,7 @@ impl Shape {
 
             vertices: VerticesInner::new(),
             cycles: CyclesInner::new(),
-            faces: Faces { faces: Vec::new() },
+            faces: FacesInner::new(),
         }
     }
 
@@ -83,8 +83,10 @@ impl Shape {
     }
 
     /// Access the shape's faces
-    pub fn faces(&mut self) -> &mut Faces {
-        &mut self.faces
+    pub fn faces(&mut self) -> Faces {
+        Faces {
+            faces: &mut self.faces,
+        }
     }
 }