--- /dev/null
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xerrors_test
+
+import (
+ "fmt"
+ "os"
+
+ "golang.org/x/xerrors"
+)
+
+func ExampleAs() {
+ _, err := os.Open("non-existing")
+ if err != nil {
+ var pathError *os.PathError
+ if xerrors.As(err, &pathError) {
+ fmt.Println("Failed at path:", pathError.Path)
+ }
+ }
+
+ // Output:
+ // Failed at path: non-existing
+}