use field::{Field, FieldHeight};

pub struct FieldWithHeight<F: Field> {
    field: F,
    height: [u16; 8],
}

impl<F: Field> FieldWithHeight<F> {
    pub fn new() -> FieldWithHeight<F> {
        FieldWithHeight::<F> {
            field: F::new(),
            height: [0; 8],
        }
    }

    pub fn field(&self) -> &F {
        &self.field
    }

    pub fn field_mut(&mut self) -> &mut F {
        &mut self.field
    }
}

impl<F: Field> FieldHeight for FieldWithHeight<F> {
    #[inline]
    fn height(&self, x: usize) -> usize {
        self.height[x] as usize
    }
}

use field::{Field, FieldHeight};

pub struct FieldWithHeight<F: Field> {
    field: F,
    height: [u16; 8],
}

impl<F: Field> FieldWithHeight<F> {
    pub fn new() -> FieldWithHeight<F> {
        FieldWithHeight::<F> {
            field: F::new(),
            height: [0; 8],
        }
    }
}

impl<F: Field> FieldHeight for FieldWithHeight<F> {
    #[inline]
    fn height(&self, x: usize) -> usize {
        self.height[x] as usize
    }
}

--- 
+++ 
@@ -12,6 +12,14 @@
             height: [0; 8],
         }
     }
+
+    pub fn field(&self) -> &F {
+        &self.field
+    }
+
+    pub fn field_mut(&mut self) -> &mut F {
+        &mut self.field
+    }
 }
 
 impl<F: Field> FieldHeight for FieldWithHeight<F> {
Add field() and field_mut() to FieldWithHeight
