queryx: add binding transformer

transformer.go

@@ -0,0 +1,13 @@
+// Copyright (C) 2017 ScyllaDB
+// Use of this source code is governed by a ALv2-style
+// license that can be found in the LICENSE file.
+
+package gocqlx
+
+// Transformer transforms the value of the named parameter to another value.
+type Transformer func(name string, val interface{}) interface{}
+
+// DefaultBindTransformer just do nothing.
+//
+// A custom transformer can always be set per Query.
+var DefaultBindTransformer Transformer