Added preconditions to subscript to avoid unwanted changes or crashes.

Andrés Pesate · Andrés Pesate · commit c77a74803bc8 · 2016-07-01T15:30:58.000+02:00
diff --git a/Array2D/Array2D.swift b/Array2D/Array2D.swift
@@ -19,6 +19,9 @@ public struct Array2D<T> {
       return array[row*columns + column]
     }
     set {
+      precondition(row < rows, "Row \(row) Index is out of range. Array<T>(columns: \(columns), rows:\(rows))")
+      precondition(column < columns, "Column \(column) Index is out of range. Array<T>(columns: \(columns), rows:\(rows))")
+        
       array[row*columns + column] = newValue
     }
   }

Original file line number	Diff line number	Diff line change
`@@ -19,6 +19,9 @@ public struct Array2D<T> {`
`19`	`19`	`return array[row*columns + column]`
`20`	`20`	`}`
`21`	`21`	`set {`
	`22`	`+ precondition(row < rows, "Row \(row) Index is out of range. Array<T>(columns: \(columns), rows:\(rows))")`
	`23`	`+ precondition(column < columns, "Column \(column) Index is out of range. Array<T>(columns: \(columns), rows:\(rows))")`
	`24`	`+`
`22`	`25`	`array[row*columns + column] = newValue`
`23`	`26`	`}`
`24`	`27`	`}`