fix the linux build.

code/ASE/ASEParser.h

@@ -80,7 +80,18 @@ struct Material : public D3DS::Material
     }
 
     Material(const Material &other)            = default;
-    Material &operator=(const Material &other) = default;
+
+    Material &operator=(const Material &other) {
+        if (this == &other) {
+            return *this;
+        }
+
+        avSubMaterials = other.avSubMaterials;
+        pcInstance = other.pcInstance;
+        bNeed = other.bNeed;
+
+        return *this;
+    }
 
 
     //! Move constructor. This is explicitly written because MSVC doesn't support defaulting it
@@ -94,12 +105,12 @@ struct Material : public D3DS::Material
     }
 
 
-    Material &operator=(Material &&other) AI_NO_EXCEPT {
+    Material &operator=( Material &&other) AI_NO_EXCEPT {
         if (this == &other) {
             return *this;
         }
 
-        D3DS::Material::operator=(std::move(other));
+        //D3DS::Material::operator=(std::move(other));
 
         avSubMaterials = std::move(other.avSubMaterials);
         pcInstance = std::move(other.pcInstance);