Add pgtype GenericText and GenericBinary

Rows.Values uses this for unknown types.

pgtype/generic_text.go

@@ -0,0 +1,29 @@
+package pgtype
+
+import (
+	"io"
+)
+
+// GenericText is a placeholder for text format values that no other type exists
+// to handle.
+type GenericText Text
+
+func (dst *GenericText) Set(src interface{}) error {
+	return (*Text)(dst).Set(src)
+}
+
+func (dst *GenericText) Get() interface{} {
+	return (*Text)(dst).Get()
+}
+
+func (src *GenericText) AssignTo(dst interface{}) error {
+	return (*Text)(src).AssignTo(dst)
+}
+
+func (dst *GenericText) DecodeText(src []byte) error {
+	return (*Text)(dst).DecodeText(src)
+}
+
+func (src GenericText) EncodeText(w io.Writer) (bool, error) {
+	return (Text)(src).EncodeText(w)
+}