Make Grid a Specialized trait

raster/src/main/scala/geotrellis/raster/CellGrid.scala

@@ -21,6 +21,6 @@ import spire.math.Integral
 /**
   * A grid composed of cells with specific value types
   */
-abstract class CellGrid[N: Integral] extends Grid[N] {
+abstract class CellGrid[N: Integral] extends GridIntegral[N] {
   def cellType: CellType
 }

raster/src/main/scala/geotrellis/raster/Grid.scala

@@ -16,12 +16,9 @@
 
 package geotrellis.raster
 
-import spire.math.Integral
-import spire.implicits._
-
-abstract class Grid[@specialized(Int, Long) N: Integral] extends Serializable {
+trait Grid[@specialized(Int, Long) N] extends Serializable {
   def cols: N
   def rows: N
-  def size: N = cols * rows
-  def dimensions: Dimensions[N] = Dimensions(cols, rows)
+  def size: N
+  def dimensions: Dimensions[N]
 }

raster/src/main/scala/geotrellis/raster/GridExtent.scala

@@ -33,13 +33,13 @@ import spire.implicits._
   * The constructor will throw [[java.lang.IllegalArgumentException]] if the provided extent and cell size do not match the
   * provided cols and rows (dimensions).
   */
-class GridExtent[@specialized(Int, Long) N: Integral](
+class GridExtent[N: Integral](
   val extent: Extent,
   val cellwidth: Double,
   val cellheight: Double,
   val cols: N,
   val rows: N
-) extends Grid[N] with Serializable {
+) extends GridIntegral[N] with Serializable {
   import GridExtent._
 
   if (cols <= 0) throw GeoAttrsError(s"invalid cols: $cols")

raster/src/main/scala/geotrellis/raster/GridIntegral.scala

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 Azavea
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package geotrellis.raster
+
+import spire.math.Integral
+import spire.implicits._
+
+abstract class GridIntegral[N: Integral] extends Grid[N] {
+  def size: N = cols * rows
+  def dimensions: Dimensions[N] = Dimensions(cols, rows)
+}