Adding list roles operation
diff --git a/openstack/identity/v2/extensions/admin/roles/results.go b/openstack/identity/v2/extensions/admin/roles/results.go
new file mode 100644
index 0000000..c829c01
--- /dev/null
+++ b/openstack/identity/v2/extensions/admin/roles/results.go
@@ -0,0 +1,43 @@
+package roles
+
+import (
+ "github.com/mitchellh/mapstructure"
+
+ "github.com/rackspace/gophercloud/pagination"
+)
+
+type Role struct {
+ // The unique ID for the role.
+ ID string
+
+ // The human-readable name of the role.
+ Name string
+
+ // The description of the role.
+ Description string
+}
+
+// RolePage is a single page of a user Role collection.
+type RolePage struct {
+ pagination.SinglePageBase
+}
+
+// IsEmpty determines whether or not a page of Tenants contains any results.
+func (page RolePage) IsEmpty() (bool, error) {
+ users, err := ExtractRoles(page)
+ if err != nil {
+ return false, err
+ }
+ return len(users) == 0, nil
+}
+
+// ExtractRoles returns a slice of roles contained in a single page of results.
+func ExtractRoles(page pagination.Page) ([]Role, error) {
+ casted := page.(RolePage).Body
+ var response struct {
+ Roles []Role `mapstructure:"roles"`
+ }
+
+ err := mapstructure.Decode(casted, &response)
+ return response.Roles, err
+}