Overload Index for PostgresRow

RowIndex has to be implemented for int unfortunately since that's what a
literal ends up resolving to.

src/lib.rs

@@ -655,23 +655,37 @@ impl<'self> Container for PostgresRow<'self> {
     }
 }
 
-impl<'self, T: FromSql> Index<uint, T> for PostgresRow<'self> {
-    fn index(&self, idx: &uint) -> T {
-        self.get(*idx)
-    }
-}
-
-impl<'self> PostgresRow<'self> {
-    pub fn get<T: FromSql>(&self, idx: uint) -> T {
+impl<'self, I: RowIndex, T: FromSql> Index<I, T> for PostgresRow<'self> {
+    fn index(&self, idx: &I) -> T {
+        let idx = idx.idx(self.stmt);
         FromSql::from_sql(self.stmt.result_desc[idx].type_oid,
                           &self.data[idx])
     }
+}
 
-    pub fn get_named<T: FromSql>(&self, col: &str) -> T {
-        let idx = match self.stmt.find_col_named(col) {
-            Some(idx) => idx,
-            None => fail!("No column with name %s", col)
-        };
-        self.get(idx)
+pub trait RowIndex {
+    fn idx(&self, stmt: &PostgresStatement) -> uint;
+}
+
+impl RowIndex for uint {
+    fn idx(&self, _stmt: &PostgresStatement) -> uint {
+        *self
+    }
+}
+
+// This is a convenicence as the 0 in get[0] resolves to int :(
+impl RowIndex for int {
+    fn idx(&self, _stmt: &PostgresStatement) -> uint {
+        assert!(*self >= 0);
+        *self as uint
+    }
+}
+
+impl<'self> RowIndex for &'self str {
+    fn idx(&self, stmt: &PostgresStatement) -> uint {
+        match stmt.find_col_named(*self) {
+            Some(idx) => idx,
+            None => fail!("No column with name %s", *self)
+        }
     }
 }

src/test.rs

@@ -272,7 +272,7 @@ fn test_find_col_named() {
 }
 
 #[test]
-fn test_find_get_named() {
+fn test_get_named() {
     do test_in_transaction |trans| {
         trans.update("CREATE TABLE foo (
                         id SERIAL PRIMARY KEY,
@@ -283,7 +283,20 @@ fn test_find_get_named() {
         let result = stmt.query([]);
 
         assert_eq!(~[10i32],
-                   result.map(|row| { row.get_named("val") }).collect());
+                   result.map(|row| { row["val"] }).collect());
+    }
+}
+
+#[test]
+#[should_fail]
+fn test_get_named_fail() {
+    do test_in_transaction |trans| {
+        trans.update("CREATE TABLE foo (id SERIAL PRIMARY KEY)", []);
+        trans.update("INSERT INTO foo DEFAULT VALUES", []);
+        let stmt = trans.prepare("SELECT id FROM foo");
+        let mut result = stmt.query([]);
+
+        let _: i32 = result.next().unwrap()["asdf"];
     }
 }