Implement AsRef<Statement> for Row(s) (#887)

src/row.rs

@@ -78,6 +78,11 @@ impl<'stmt> Rows<'stmt> {
     {
         AndThenRows { rows: self, map: f }
     }
+
+    /// Give access to the underlying statement
+    pub fn as_ref(&self) -> Option<&Statement<'stmt>> {
+        self.stmt
+    }
 }
 
 impl<'stmt> Rows<'stmt> {
@@ -358,6 +363,12 @@ impl<'stmt> Row<'stmt> {
     }
 }
 
+impl<'stmt> AsRef<Statement<'stmt>> for Row<'stmt> {
+    fn as_ref(&self) -> &Statement<'stmt> {
+        self.stmt
+    }
+}
+
 mod sealed {
     /// This trait exists just to ensure that the only impls of `trait Params`
     /// that are allowed are ones in this crate.