SimMeta: make the fields private

crates/coremem/src/sim/mod.rs

@@ -235,10 +235,10 @@ pub trait AbstractSim: Sync {
     }
 
     fn size(&self) -> Index {
-        Index(self.meta().dim)
+        Index(self.meta().dim())
     }
     fn feature_size(&self) -> f32 {
-        self.meta().feature_size
+        self.meta().feature_size()
     }
     fn feature_volume(&self) -> f32 {
         let f = self.feature_size();
@@ -249,7 +249,7 @@ pub trait AbstractSim: Sync {
         s.x() * s.y() * s.z()
     }
     fn timestep(&self) -> f32 {
-        self.meta().time_step
+        self.meta().time_step()
     }
 
     fn width(&self) -> u32 {