From 454398985c6bbd113cc051e5b7d17800de455b69 Mon Sep 17 00:00:00 2001
From: Blake Thompson <flippmoke@gmail.com>
Date: Thu, 19 Mar 2015 13:42:17 -0500
Subject: [PATCH] Implementing < and == operators in image

---
 include/mapnik/image.hpp      |  2 ++
 include/mapnik/image_impl.hpp | 16 ++++++++++++----
 include/mapnik/image_null.hpp |  5 ++++-
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/include/mapnik/image.hpp b/include/mapnik/image.hpp
index 833a9989e..2b824af21 100644
--- a/include/mapnik/image.hpp
+++ b/include/mapnik/image.hpp
@@ -94,6 +94,8 @@ public:
     image(image<T> && rhs) noexcept;
     image<T>& operator=(image<T> rhs);
     image<T>const& operator=(image<T> const& rhs) const;
+    bool operator==(image<T> const& rhs) const;
+    bool operator<(image<T> const& rhs) const;
 
     void swap(image<T> & rhs);
     pixel_type& operator() (std::size_t i, std::size_t j);
diff --git a/include/mapnik/image_impl.hpp b/include/mapnik/image_impl.hpp
index e47f2a086..44d9bd298 100644
--- a/include/mapnik/image_impl.hpp
+++ b/include/mapnik/image_impl.hpp
@@ -20,9 +20,6 @@
  *
  *****************************************************************************/
 
-#ifndef MAPNIK_IMAGE_IMPL_HPP
-#define MAPNIK_IMAGE_IMPL_HPP
-
 // mapnik
 #include <mapnik/image.hpp>
 
@@ -134,6 +131,18 @@ image<T> const& image<T>::operator=(image<T> const& rhs) const
     return rhs;
 }
 
+template <typename T>
+bool image<T>::operator==(image<T> const& rhs) const
+{
+    return rhs.getBytes() == getBytes();
+}
+
+template <typename T>
+bool image<T>::operator<(image<T> const& rhs) const
+{
+    return getSize() < rhs.getSize();
+}
+
 template <typename T>
 void image<T>::swap(image<T> & rhs)
 {
@@ -314,4 +323,3 @@ inline image_dtype image<T>::get_dtype()  const
 
 } // end ns
 
-#endif // MAPNIK_IMAGE_IMPL_HPP
diff --git a/include/mapnik/image_null.hpp b/include/mapnik/image_null.hpp
index c882646d1..af7123ca6 100644
--- a/include/mapnik/image_null.hpp
+++ b/include/mapnik/image_null.hpp
@@ -25,7 +25,6 @@
 
 // mapnik
 #include <mapnik/config.hpp>
-//#include <mapnik/image.hpp>
 #include <mapnik/pixel_types.hpp>
 
 //stl
@@ -50,6 +49,10 @@ public:
           bool painted = false) {}
     image(image<null_t> const& rhs) {}
     image(image<null_t> && rhs) noexcept {}
+    image<null_t>& operator=(image<null_t> rhs) { return *this; }
+    image<null_t>const& operator=(image<null_t> const& rhs) const { return rhs; }
+    bool operator==(image<null_t> const& rhs) const { return true; }
+    bool operator<(image<null_t> const& rhs) const { return false; }
 
     std::size_t width() const { return 0; }
     std::size_t height() const { return 0; }