From 0471f3369a2667a362bc30e7d9949a55e588f14c Mon Sep 17 00:00:00 2001
From: artemp <artem@mapnik.org>
Date: Mon, 15 Aug 2016 12:20:19 +0100
Subject: [PATCH] add order_by_name helper method

---
 include/mapnik/feature_layer_desc.hpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/mapnik/feature_layer_desc.hpp b/include/mapnik/feature_layer_desc.hpp
index 9d1186a7c..cd69d831f 100644
--- a/include/mapnik/feature_layer_desc.hpp
+++ b/include/mapnik/feature_layer_desc.hpp
@@ -94,12 +94,21 @@ public:
     {
         return extra_params_;
     }
+
     bool has_name(std::string const& name) const
     {
         auto result = std::find_if(std::begin(descriptors_), std::end(descriptors_),
                                 [&name](attribute_descriptor const& desc) { return name == desc.get_name();});
         return result != std::end(descriptors_);
     }
+    void order_by_name()
+    {
+        std::sort(std::begin(descriptors_), std::end(descriptors_),
+                  [](attribute_descriptor const& d0, attribute_descriptor const& d1)
+                  {
+                      return d0.get_name() < d1.get_name();
+                  });
+    }
 private:
     std::string name_;
     std::string encoding_;