Remove unneeded Undefined property.

The nullptr is probably sufficient in the PropertyArray,
which is an array of pointers, for the property to be
undefined.

MaterialLib/MPL/Component.cpp

@@ -19,19 +19,11 @@ namespace MaterialPropertyLib
 {
 Component::Component()
 {
-    // This method initializes the component property array with constant
-    // functions of value zero.
-    _properties = createDefaultUndefinedProperties();
-
     // Some properties can be initialized by other default properties:
     _properties[name] = std::make_unique<Constant>("no_name");
 }
 Component::Component(std::string const& component_name)
 {
-    // This method initializes the component property array with constant
-    // functions of value zero.
-    _properties = createDefaultUndefinedProperties();
-
     // Some properties can be initialized by other default properties:
     _properties[name] = std::make_unique<Constant>(component_name);
 }

MaterialLib/MPL/Medium.cpp

@@ -26,16 +26,6 @@ namespace MaterialPropertyLib
 {
 Medium::Medium(BaseLib::ConfigTree const& config)
 {
-    // Default properties are initialized in the first place, such that
-    // user-defined properties overwrite those defaults.
-    //
-    // A method that creates the default properties of the medium.  Currently,
-    // these defaults is the volume fraction average.
-    //
-    // Most properties are fine with the volume fraction average, but
-    // special-defaults are allowed as well...
-    _properties = createDefaultUndefinedProperties();
-
     // A name of a medium is entirely optional and has no effects
     // other than a small gain of clarity in case several media
     // should be defined.

MaterialLib/MPL/Medium.h

@@ -30,6 +30,11 @@ class Medium
     /// The vector that holds the phases.
     std::vector<std::unique_ptr<Phase>> _phases;
     /// The array that holds the medium properties.
+    ///
+    /// Currently, these defaults is the volume fraction average.
+    ///
+    /// Most properties are fine with the volume fraction average, but
+    /// special-defaults are allowed as well...
     PropertyArray _properties;
 
 public:

MaterialLib/MPL/Phase.cpp

@@ -21,13 +21,6 @@ namespace MaterialPropertyLib
 {
 Phase::Phase(std::string const& phase_name)
 {
-    // Here, all for all properties listed in the Properties enumerator are
-    // initialized by mole average functions of value zero. However,
-    // 'special-default' properties are allowed to be set.
-    //
-    // After this, other special properties can be set as exceptional defaults.
-    _properties = createDefaultUndefinedProperties();
-
     std::array<std::string, 4> allowed_phase_names = {
         {"solid", "aqueous liquid", "non-aqueous liquid", "gas"}};
 

MaterialLib/MPL/Phase.h

@@ -29,6 +29,12 @@ class Phase final
 {
 private:
     std::vector<std::unique_ptr<Component>> _components;
+
+    /// Here, all for all properties listed in the Properties enumerator are
+    /// initialized by mole average functions of value zero. However,
+    /// 'special-default' properties are allowed to be set.
+    ///
+    /// After this, other special properties can be set as exceptional defaults.
     PropertyArray _properties;
 
 public:

MaterialLib/MPL/Properties/Properties.h

@@ -12,21 +12,4 @@
  */
 #pragma once
 
-#include <memory>
 #include "Constant.h"
-#include "Undefined.h"
-
-namespace MaterialPropertyLib
-{
-inline PropertyArray createDefaultUndefinedProperties()
-{
-    PropertyArray properties;
-    for (std::size_t i = 0; i < numberOfProperties; ++i)
-    {
-        properties[i] =
-            std::make_unique<Undefined>(static_cast<PropertyType>(i));
-    }
-
-    return properties;
-}
-}  // namespace MaterialPropertyLib