pclass: Implement string primitives and class types

include/ki/pclass/HashCalculator.h

@@ -25,11 +25,10 @@ namespace ki
 			virtual hash_t calculate_type_hash(const std::string &name) const = 0;
 
 			/**
-			* Calculate a property hash from the property's name and type.
+			* Calculate a property hash from the property's name.
 			* @param name The name of the property.
-			* @param type_hash The hash of the property's type.
 			*/
-			virtual hash_t calculate_property_hash(const std::string& name, const hash_t type_hash) const = 0;
+			virtual hash_t calculate_property_hash(const std::string& name) const = 0;
 		};
 
 		/**
@@ -40,7 +39,7 @@ namespace ki
 		{
 		public:
 			hash_t calculate_type_hash(const std::string& name) const override;
-			hash_t calculate_property_hash(const std::string& name, const hash_t type_hash) const override;
+			hash_t calculate_property_hash(const std::string& name) const override;
 		};
 	}
 }

include/ki/pclass/Property.h

@@ -0,0 +1,65 @@
+#pragma once
+#include "ki/pclass/types/Type.h"
+
+namespace ki
+{
+namespace pclass
+{
+	class PropertyClass;
+
+	/**
+ 	 * TODO: Documentation
+	 */
+	class PropertyBase
+	{
+	public:
+		PropertyBase(PropertyClass &object,
+			const std::string &name, const Type &type);
+		virtual ~PropertyBase() { }
+
+		std::string get_name() const;
+		hash_t get_name_hash() const;
+		hash_t get_full_hash() const;
+		const Type &get_type() const;
+
+		virtual bool is_pointer() const;
+		virtual bool is_dynamic() const;
+
+		virtual Value get_value() const = 0;
+		virtual const PropertyClass *get_object() const = 0;
+
+		virtual void write_value_to(BitStream &stream) const = 0;
+		virtual void read_value_from(BitStream &stream) = 0;
+
+	private:
+		std::string m_name;
+		hash_t m_name_hash;
+		hash_t m_full_hash;
+		const Type *m_type;
+	};
+
+	/**
+	 * TODO: Documentation
+	 */
+	class DynamicPropertyBase : public PropertyBase
+	{
+	public:
+		DynamicPropertyBase(PropertyClass &object,
+			const std::string &name, const Type &type);
+		virtual ~DynamicPropertyBase() {}
+
+		bool is_dynamic() const override;
+		virtual std::size_t get_element_count() const = 0;
+
+		Value get_value() const final override;
+		const PropertyClass *get_object() const final override;
+		void write_value_to(BitStream &stream) const final override;
+		void read_value_from(BitStream &stream) final override;
+
+		virtual Value get_value(int index) const = 0;
+		virtual const PropertyClass *get_object(int index) const = 0;
+		virtual void write_value_to(BitStream &stream, int index) const = 0;
+		virtual void read_value_from(BitStream &stream, int index) = 0;
+	};
+}
+}

include/ki/pclass/PropertyClass.h

@@ -1,24 +1,60 @@
 #pragma once
+#include "ki/pclass/types/Type.h"
+#include "ki/pclass/PropertyList.h"
+
+#define _KI_TYPE ki::pclass::Type
+#define _KI_TYPE_SYSTEM ki::pclass::TypeSystem
+#define _KI_PCLASS ki::pclass::PropertyClass
+
+#define _KI_PCLASS_CONSTRUCTOR(derived) \
+explicit derived(const _KI_TYPE &type, const _KI_TYPE_SYSTEM &type_system)
+
+#define _KI_PCLASS_CONSTRUCT_BASE(base) \
+: base(type, type_system)
+
+#define DERIVED_PCLASS(derived, base) class derived : public base
+#define PCLASS(n) DERIVED_PCLASS(n, _KI_PCLASS)
+
+#define PCLASS_CONSTRUCTOR(derived) \
+_KI_PCLASS_CONSTRUCTOR(derived) \
+	_KI_PCLASS_CONSTRUCT_BASE(_KI_PCLASS)
+
+#define DERIVED_PCLASS_CONSTRUCTOR(derived, base) \
+_KI_PCLASS_CONSTRUCTOR(derived) \
+	_KI_PCLASS_CONSTRUCT_BASE(base)
+
+#define TYPE(n) type_system.get_type(n)
+
+#define INIT_PROPERTY(identifier, type) \
+	, identifier(*this, #identifier, TYPE(type))
+
+#define INIT_PROPERTY_VALUE(identifier, type, value) \
+	, identifier(*this, #identifier, TYPE(type), value)
 
 namespace ki
 {
 namespace pclass
 {
-	class Type;
+	template <typename ValueT>
+	class ClassType;
 
 	/**
 	 * TODO: Documentation
 	 */
 	class PropertyClass
 	{
-		explicit PropertyClass(const Type &type) : m_type(type) {}
+	public:
-		virtual ~PropertyClass() {};
+		explicit PropertyClass(const Type &type, const TypeSystem &type_system);
+		virtual ~PropertyClass();
 
-		const Type &get_type();
+		const Type &get_type() const;
+
+		PropertyList &get_properties();
+		const PropertyList &get_properties() const;
 
-		virtual void on_created();
 	private:
-		const Type &m_type;
+		const Type *m_type;
+		PropertyList *m_properties;
 	};
 }
 }

include/ki/pclass/PropertyList.h

@@ -0,0 +1,43 @@
+#pragma once
+#include <map>
+#include <vector>
+#include "ki/pclass/HashCalculator.h"
+
+namespace ki
+{
+namespace pclass
+{
+	class PropertyBase;
+
+	/**
+	 * TODO: Documentation
+	 */
+	class PropertyList
+	{
+		friend PropertyBase;
+
+	public:
+		using const_iterator = std::vector<PropertyBase *>::const_iterator;
+
+		std::size_t get_property_count() const;
+
+		bool has_property(const std::string &name) const;
+		bool has_property(hash_t hash) const;
+
+		const PropertyBase &get_property(int index) const;
+		const PropertyBase &get_property(const std::string &name) const;
+		const PropertyBase &get_property(hash_t hash) const;
+
+		const_iterator begin() const;
+		const_iterator end() const;
+
+	protected:
+		void add_property(PropertyBase *prop);
+
+	private:
+		std::vector<PropertyBase *> m_properties;
+		std::map<std::string, PropertyBase *> m_property_name_lookup;
+		std::map<hash_t, PropertyBase *> m_property_hash_lookup;
+	};
+}
+}

include/ki/pclass/StaticProperty.h

@@ -0,0 +1,307 @@
+#pragma once
+#include "ki/pclass/Property.h"
+#include "ki/util/exception.h"
+
+namespace ki
+{
+namespace pclass
+{
+	// Forward declare StaticProperty<ValueT> for our helpers
+	template <typename ValueT>
+	class StaticProperty;
+
+	/**
+	 * A helper utility that provides the right implementation of construct()
+	 * and get_object() based on characteristics of type: ValueT.
+	 */
+	template <
+		typename ValueT,
+		typename IsPointerEnable = void,
+		typename IsBaseEnable = void
+	>
+	struct value_object_helper
+	{
+		static ValueT construct(const Type &type)
+		{
+			// In cases where ValueT is not a pointer, and does not derive from PropertyClass,
+			// just call the default constructor.
+			return ValueT();
+		}
+
+		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
+		{
+			// ValueT does not derive from PropertyClass, and so, this property is not
+			// storing an object.
+			throw runtime_error(
+				"Tried calling get_object() on a property that does not store an object."
+			);
+		}
+	};
+
+	/**
+	 * Specialization for when ValueT is:
+	 * - A pointer; but
+	 * - does not derive from PropertyClass
+	 * 
+	 * This should construct to a nullptr, and throw an exception
+	 * when get_object()is called.
+	 */
+	template <typename ValueT>
+	struct value_object_helper<
+		ValueT,
+		typename std::enable_if<
+			std::is_pointer<ValueT>::value
+		>::type,
+		typename std::enable_if<
+			!std::is_base_of<
+				PropertyClass,
+				typename std::remove_pointer<ValueT>::type
+			>::value
+		>::type
+	>
+	{
+		static ValueT construct(const Type &type)
+		{
+			// The default value of pointers is null
+			return nullptr;
+		}
+
+		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
+		{
+			// ValueT does not derive from PropertyClass, and so, this property is not
+			// storing an object.
+			throw runtime_error(
+				"Tried calling get_object() on a property that does not store an object."
+			);
+		}
+	};
+
+	/**
+	 * Specialization for when ValueT is:
+	 * - A pointer; and
+	 * - does derive from PropertyClass
+	 * 
+	 * This should construct to a nullptr, and return a pointer to
+	 * a ValueT instance (as a PropertyClass *) when get_object() is called.
+	 */
+	template <typename ValueT>
+	struct value_object_helper<
+		ValueT,
+		typename std::enable_if<
+			std::is_pointer<ValueT>::value
+		>::type,
+		typename std::enable_if<
+			std::is_base_of<
+				PropertyClass,
+				typename std::remove_pointer<ValueT>::type
+			>::value
+		>::type
+	>
+	{
+		static ValueT construct(const Type &type)
+		{
+			// The default value of pointers is null
+			return nullptr;
+		}
+
+		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
+		{
+			// ValueT does derive from PropertyClass, and we have a pointer to an instance
+			// of ValueT, so we can cast down to a PropertyClass pointer.
+			return dynamic_cast<const PropertyClass *>(prop.m_value);
+		}
+	};
+
+	/**
+	 * Specialization for when ValueT is:
+	 * - Not a pointer; and
+	 * - does derive from PropertyClass
+	 * 
+	 * This should construct an instance of ValueT by passing the property
+	 * type and the type's type system, and return a pointer to a ValueT
+	 * instance (as a PropertyClass *) when get_object() is called.
+	 */
+	template <typename ValueT>
+	struct value_object_helper<
+		ValueT,
+		typename std::enable_if<
+			!std::is_pointer<ValueT>::value
+		>::type,
+		typename std::enable_if<
+			std::is_base_of<
+				PropertyClass,
+				typename std::remove_pointer<ValueT>::type
+			>::value
+		>::type
+	>
+	{
+		static ValueT construct(const Type &type)
+		{
+			// Derivitives of PropertyClass cannot have a default constructor since
+			// they require their Type and TypeSystem, so we need to pass these
+			// along from what the StaticProperty constructor has been given.
+			return ValueT(type, type.get_type_system());
+		}
+
+		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
+		{
+			// ValueT does derive from PropertyClass, and we have an instance of ValueT,
+			// so we can cast down to a PropertyClass pointer.
+			return dynamic_cast<const PropertyClass *>(&prop.m_value);
+		}
+	};
+	
+	/**
+	 * A helper utility that provides the right implementation of write() and read()
+	 * based on whether ValueT is a pointer.
+	 */
+	template <
+		typename ValueT,
+		typename IsPointerEnable = void
+	>
+	struct value_rw_helper
+	{
+		static void write(const StaticProperty<ValueT> &prop, BitStream &stream)
+		{
+			prop.get_type().write_to(stream, prop.m_value);
+		}
+
+		static void read(StaticProperty<ValueT> &prop, BitStream &stream)
+		{
+			prop.get_type().read_from(stream, Value(prop.m_value));
+		}
+	};
+
+	/**
+	* Specialization for when ValueT is a pointer.
+	* 
+	* Dereference the pointer before creating Value instances.
+	* This is so that the Value stores a pointer to a ValueT instance,
+	* rather than storing a pointer to a pointer.
+	*/
+	template <typename ValueT>
+	struct value_rw_helper<
+		ValueT,
+		typename std::enable_if<
+			std::is_pointer<ValueT>::value
+		>::type
+	>
+	{
+		static void write(const StaticProperty<ValueT> &prop, BitStream &stream)
+		{
+			prop.get_type().write_to(stream, *prop.m_value);
+		}
+
+		static void read(StaticProperty<ValueT> &prop, BitStream &stream)
+		{
+			prop.get_type().read_from(stream, Value(*prop.m_value));
+		}
+	};
+
+	/**
+	 * A helper utility that combines functions provided by value_object_helper
+	 * and value_rw_helper into a single type.
+	 */
+	template <typename ValueT>
+	struct value_helper
+	{
+		static ValueT construct(const Type &type)
+		{
+			return value_object_helper<ValueT>::construct(type);
+		}
+
+		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
+		{
+			return value_object_helper<ValueT>::get_object(prop);
+		}
+
+		static void write(const StaticProperty<ValueT> &prop, BitStream &stream)
+		{
+			value_rw_helper<ValueT>::write(prop, stream);
+		}
+
+		static void read(StaticProperty<ValueT> &prop, BitStream &stream)
+		{
+			value_rw_helper<ValueT>::read(prop, stream);
+		}
+	};
+
+	/**
+	 * TODO: Documentation
+	 */
+	template <typename ValueT>
+	class StaticProperty : public PropertyBase
+	{
+		// Allow helper utilities access to m_value
+		friend value_object_helper<ValueT>;
+		friend value_rw_helper<ValueT>;
+
+	public:
+		StaticProperty(PropertyClass &object,
+			const std::string &name, const Type &type)
+			: PropertyBase(object, name, type)
+			, m_value(value_helper<ValueT>::construct(type))
+		{}
+
+		StaticProperty(PropertyClass &object,
+			const std::string &name, const Type &type, ValueT value)
+			: PropertyBase(object, name, type)
+		{
+			m_value = value;
+		}
+
+		constexpr bool is_dynamic() const override
+		{
+			return false;
+		}
+
+		constexpr bool is_pointer() const override
+		{
+			return std::is_pointer<ValueT>::value;
+		}
+
+		void write_value_to(BitStream &stream) const override
+		{
+			value_helper<ValueT>::write(*this, stream);
+		}
+
+		void read_value_from(BitStream &stream) override
+		{
+			value_helper<ValueT>::read(*this, stream);
+		}
+
+		const PropertyClass *get_object() const override
+		{
+			return value_helper<ValueT>::get_object(*this);
+		}
+
+		ValueT &get()
+		{
+			return m_value;
+		}
+
+		Value get_value() const override
+		{
+			return m_value;
+		}
+
+		operator ValueT &() const
+		{
+			return m_value;
+		}
+
+		ValueT *operator&() const
+		{
+			return &m_value;
+		}
+
+		void operator=(const ValueT &value)
+		{
+			m_value = value;
+		}
+
+	protected:
+		ValueT m_value;
+	};
+}
+}

include/ki/pclass/TypeSystem.h

@@ -1,8 +1,11 @@
 #pragma once
 #include <vector>
 #include <map>
-#include "Type.h"
+#include "ki/pclass/HashCalculator.h"
-#include "PrimitiveType.h"
+#include "ki/pclass/types/Type.h"
+#include "ki/pclass/types/PrimitiveType.h"
+#include "ki/pclass/types/ClassType.h"
+#include "ki/pclass/types/EnumType.h"
 
 namespace ki
 {
@@ -14,52 +17,61 @@ namespace pclass
 	class TypeSystem
 	{
 	public:
-		/**
-		 * @return A singleton instance of TypeSystem with all C++ primitives defined.
-		 */
-		static TypeSystem &get_singleton();
-
 		explicit TypeSystem(HashCalculator *hash_calculator);
 		~TypeSystem();
 
+		const HashCalculator &get_hash_calculator() const;
 		void set_hash_calculator(HashCalculator *hash_calculator);
 
-		Type &get_type(const std::string &name) const;
+		bool has_type(const std::string &name) const;
-		Type &get_type(hash_t hash) const;
+		bool has_type(hash_t hash) const;
+
+		const Type &get_type(const std::string &name) const;
+		const Type &get_type(hash_t hash) const;
 
 		template <typename ValueT>
-		Type &define_primitive(const std::string &name)
+		PrimitiveType<ValueT> &define_primitive(const std::string &name)
 		{
-			auto hash = m_hash_calculator->calculate_type_hash(name);
+			auto *type = new PrimitiveType<ValueT>(name, *this);
-			auto *type = new PrimitiveType<ValueT>(name, hash);
 			define_type(type);
 			return *type;
 		}
 
 		template <class ClassT>
-		Type &define_class(const std::string &name)
+		ClassType<ClassT> &define_class(
+			const std::string &name, const Type *base_class = nullptr)
 		{
-			// Ensure that ClassT inherits PropertyClass
+			// If the caller does not specify a base class, automatically make
-			static_assert(std::is_base_of<PropertyClass, ClassT>::value, "ClassT must inherit PropertyClass!");
+			// ki::pclass::PropertyClass the base class (if it has been defined)
+			if (base_class == nullptr && has_type("class PropertyClass"))
+				base_class = &get_type("class PropertyClass");
 
-			// TODO: Create class types
+			auto *type = new ClassType<ClassT>(name, base_class, *this);
+			define_type(type);
+			return *type;
 		}
 
 		template <typename EnumT>
-		Type &define_enum(const std::string &name)
+		EnumType<EnumT> *define_enum(const std::string &name)
 		{
-			// Ensure that EnumT is an enum
+			/*
-			static_assert(std::is_enum<EnumT>::value, "EnumT must be an enum!");
+			auto *type = new EnumType<EnumT>(name, this);
+			define_type(type);
+			return type;
+			*/
+		}
 
-			// TODO: Create enum types
+		template <typename ClassT>
+		ClassT *instantiate(const std::string &name) const
+		{
+			const auto &type = get_type(name);
+			return dynamic_cast<ClassT *>(type.instantiate());
 		}
 
 	protected:
 		void define_type(Type *type);
 
 	private:
-		static TypeSystem *s_instance;
-
 		TypeList m_types;
 		TypeNameMap m_type_name_lookup;
 		TypeHashMap m_type_hash_lookup;

include/ki/pclass/Value.h

@@ -16,7 +16,14 @@ namespace pclass
 		template <typename T>
 		Value(T &value)
 		{
-			m_value_ptr = value;
+			m_value_ptr = static_cast<void *>(&value);
+			m_type_hash = typeid(value).hash_code();
+		}
+
+		template <typename T>
+		Value(const T &value)
+		{
+			m_value_ptr = const_cast<void *>(static_cast<const void *>(&value));
 			m_type_hash = typeid(value).hash_code();
 		}
 
@@ -44,7 +51,7 @@ namespace pclass
 			// Make sure that this is allowed
 			if (!is<T>())
 				throw std::runtime_error("Type mismatch in Value::get<T>() call.");
-			return *(T *)m_value_ptr;
+			return *static_cast<T *>(m_value_ptr);
 		}
 
 		/**
@@ -56,7 +63,7 @@ namespace pclass
 			// Make sure that this is allowed
 			if (!is<T>())
 				throw std::runtime_error("Type mismatch in Value::get<T>() call.");
-			return *(T *)m_value_ptr;
+			return *static_cast<T *>(m_value_ptr);
 		}
 
 	private:

include/ki/pclass/VectorProperty.h

@@ -0,0 +1,166 @@
+#pragma once
+#include <vector>
+#include "ki/pclass/Property.h"
+#include "ki/util/exception.h"
+
+namespace ki
+{
+namespace pclass
+{
+	template <typename ValueT>
+	class VectorPropertyBase : public std::vector<ValueT>, public DynamicPropertyBase
+	{
+	public:
+		VectorPropertyBase(PropertyClass &object,
+			const std::string &name, const Type &type)
+			: DynamicPropertyBase(object, name, type) { }
+
+		std::size_t get_element_count() const override
+		{
+			return this->size();
+		}
+
+		Value get_value(int index) const override
+		{
+			if (index < 0 || index >= this->size())
+				throw runtime_error("Index out of bounds.");
+			return this->at(index);
+		}
+	};
+
+	template <typename ValueT, typename Enable = void>
+	class VectorPropertyBase2 : public VectorPropertyBase<ValueT>
+	{
+		VectorPropertyBase2(PropertyClass &object,
+			const std::string &name, const Type &type)
+			: VectorPropertyBase<ValueT>(object, name, type) { }
+
+		constexpr bool is_pointer() const override
+		{
+			return false;
+		}
+
+		void write_value_to(BitStream &stream, const int index) const override
+		{
+			if (index < 0 || index >= this->size())
+				throw runtime_error("Index out of bounds.");
+			this->get_type().write_to(stream, this->at(index));
+		}
+
+		void read_value_from(BitStream &stream, const int index) override
+		{
+			if (index < 0 || index >= this->size())
+				throw runtime_error("Index out of bounds.");
+			this->get_type().read_from(stream, this->at(index));
+		}
+	};
+
+	template <typename ValueT>
+	class VectorPropertyBase2<
+		ValueT,
+		typename std::enable_if<
+			std::is_pointer<ValueT>::value
+		>::type
+	> : public VectorPropertyBase<ValueT>
+	{
+	public:
+		VectorPropertyBase2(PropertyClass &object,
+			const std::string &name, const Type &type)
+			: VectorPropertyBase<ValueT>(object, name, type) { }
+
+		constexpr bool is_pointer() const override
+		{
+			return true;
+		}
+
+		void write_value_to(BitStream &stream, const int index) const override
+		{
+			if (index < 0 || index >= this->size())
+				throw runtime_error("Index out of bounds.");
+			this->get_type().write_to(stream, *this->at(index));
+		}
+
+		void read_value_from(BitStream &stream, const int index) override
+		{
+			if (index < 0 || index >= this->size())
+				throw runtime_error("Index out of bounds.");
+			this->get_type().read_from(stream, Value(*this->at(index)));
+		}
+	};
+
+	template <
+		typename ValueT,
+		typename _IsBaseEnable = void,
+		typename _IsPointerEnable = void
+	>
+	class VectorProperty : public VectorPropertyBase2<ValueT>
+	{
+	public:
+		VectorProperty(PropertyClass &object,
+			const std::string &name, const Type &type)
+			: VectorPropertyBase2<ValueT>(object, name, type) { }
+
+		const PropertyClass *get_object(const int index) const override
+		{
+			// We aren't holding an object at all, whoever called this is mistaken.
+			throw runtime_error(
+				"Tried calling get_object(index) on a property that does not store an object."
+			);
+		}
+	};
+
+	template <typename ValueT>
+	class VectorProperty<
+		ValueT,
+		typename std::enable_if<
+			std::is_base_of<
+				PropertyClass,
+				typename std::remove_pointer<ValueT>::type
+			>::value
+		>::type,
+		typename std::enable_if<
+			!std::is_pointer<ValueT>::value
+		>::type
+	> : public VectorPropertyBase2<ValueT>
+	{
+	public:
+		VectorProperty(PropertyClass &object,
+			const std::string &name, const Type &type)
+			: VectorPropertyBase2<ValueT>(object, name, type) { }
+
+		const PropertyClass *get_object(const int index) const override
+		{
+			if (index < 0 || index >= this->size())
+				throw runtime_error("Index out of bounds.");
+			return dynamic_cast<PropertyClass *>(&this->at(index));
+		}
+	};
+
+	template <typename ValueT>
+	class VectorProperty<
+		ValueT,
+		typename std::enable_if<
+			std::is_base_of<
+				PropertyClass,
+				typename std::remove_pointer<ValueT>::type
+			>::value
+		>::type,
+		typename std::enable_if<
+			std::is_pointer<ValueT>::value
+		>::type
+	> : public VectorPropertyBase2<ValueT>
+	{
+	public:
+		VectorProperty(PropertyClass &object,
+			const std::string &name, const Type &type)
+			: VectorPropertyBase2<ValueT>(object, name, type) { }
+
+		const PropertyClass *get_object(const int index) const override
+		{
+			if (index < 0 || index >= this->size())
+				throw runtime_error("Index out of bounds.");
+			return dynamic_cast<PropertyClass *>(this->at(index));
+		}
+	};
+}
+}

include/ki/pclass/types/ClassType.h

@@ -0,0 +1,65 @@
+#pragma once
+#include <type_traits>
+#include <string>
+#include "ki/pclass/Property.h"
+#include "ki/pclass/types/Type.h"
+#include "ki/pclass/PropertyClass.h"
+#include "ki/util/exception.h"
+
+namespace ki
+{
+namespace pclass
+{
+	/**
+	 * TODO: Documentation
+	 */
+	class ClassTypeBase : public Type
+	{
+	public:
+		ClassTypeBase(const std::string &name,
+			const Type *base_class, const TypeSystem &type_system);
+		virtual ~ClassTypeBase() {}
+
+		bool inherits(const Type &type) const;
+
+	private:
+		const ClassTypeBase *m_base_class;
+	};
+
+	/**
+	* TODO: Documentation
+	*/
+	template <class ClassT>
+	class ClassType : public ClassTypeBase
+	{
+		// Ensure that ClassT inherits PropertyClass
+		static_assert(std::is_base_of<PropertyClass, ClassT>::value, "ClassT must inherit PropertyClass!");
+
+	public:
+		ClassType(const std::string &name,
+			const Type *base_class, const TypeSystem &type_system)
+			: ClassTypeBase(name, base_class, type_system) {}
+
+		PropertyClass *instantiate() const override
+		{
+			return new ClassT(*this, get_type_system());
+		}
+
+		void write_to(BitStream &stream, const Value &value) const override
+		{
+			const auto &object = dynamic_cast<const PropertyClass &>(value.get<ClassT>());
+			const auto &properties = object.get_properties();
+			for (auto it = properties.begin(); it != properties.end(); ++it)
+				(*it)->write_value_to(stream);
+		}
+
+		void read_from(BitStream &stream, Value &value) const override
+		{
+			auto &object = dynamic_cast<PropertyClass &>(value.get<ClassT>());
+			auto &properties = object.get_properties();
+			for (auto it = properties.begin(); it != properties.end(); ++it)
+				(*it)->read_value_from(stream);
+		}
+	};
+}
+}

include/ki/pclass/types/EnumType.h

@@ -0,0 +1,32 @@
+#pragma once
+#include <type_traits>
+#include "ki/pclass/types/Type.h"
+
+namespace ki
+{
+namespace pclass
+{
+	/**
+	 * TODO: Documentation
+	 */
+	class EnumOption
+	{
+	private:
+		std::string m_name;
+		uint32_t m_value;
+	};
+
+	/**
+	* TODO: Documentation
+	*/
+	template <typename EnumT>
+	class EnumType : public Type
+	{
+		// Ensure that EnumT is an enum
+		static_assert(std::is_enum<EnumT>::value, "EnumT must be an enum!");
+
+	public:
+		EnumType(std::string name, hash_t hash, TypeSystem *type_system);
+	};
+}
+}

include/ki/pclass/types/FloatingPointPrimitiveType.h

@@ -15,7 +15,9 @@ namespace ki
 		static void write_to(BitStream &stream, const ValueT &value)
 		{
 			// Reinterpret the reference as a reference to an integer
-				const uint_type &v = *((const uint_type *)&value);
+			const uint_type &v = *(
+				reinterpret_cast<const uint_type *>(&value)
+			);
 			stream.write<uint_type>(v, bitsizeof<ValueT>::value);
 		}
 
@@ -36,7 +38,9 @@ namespace ki
 		static void read_from(BitStream &stream, ValueT &value)
 		{
 			// Reinterpret the reference as a reference to an integer
-				uint_type &v = *((uint_type *)&value);
+			uint_type &v = *(
+				reinterpret_cast<uint_type *>(&value)
+			);
 			v = stream.read<uint_type>(bitsizeof<ValueT>::value);
 		}
 

include/ki/pclass/types/IntegralPrimitiveType.h

@@ -14,7 +14,7 @@ namespace pclass
 	{
 		static void write_to(BitStream &stream, const ValueT &value)
 		{
-			stream.write<ValueT>(value, bitsizeof<ValueT>::value);
+			stream.write<ValueT>(value);
 		}
 	};
 
@@ -26,7 +26,7 @@ namespace pclass
 	{
 		static void read_from(BitStream &stream, ValueT &value)
 		{
-			value = stream.read<ValueT>(bitsizeof<ValueT>::value);
+			value = stream.read<ValueT>();
 		}
 	};
 }

include/ki/pclass/types/PrimitiveType.h

@@ -1,5 +1,5 @@
 #pragma once
-#include "ki/pclass/Type.h"
+#include "ki/pclass/types/Type.h"
 
 namespace ki
 {
@@ -44,8 +44,8 @@ namespace pclass
 	class PrimitiveType : public Type
 	{
 	public:
-		PrimitiveType(const std::string name, const hash_t hash)
+		PrimitiveType(const std::string name, const TypeSystem &type_system)
-			: Type(name, hash)
+			: Type(name, type_system)
 		{
 			m_kind = kind::PRIMITIVE;
 		}
@@ -70,3 +70,4 @@ namespace pclass
 // Include all template specializations
 #include "ki/pclass/types/IntegralPrimitiveType.h"
 #include "ki/pclass/types/FloatingPointPrimitiveType.h"
+#include "ki/pclass/types/StringPrimitiveType.h"

include/ki/pclass/types/StringPrimitiveType.h

@@ -0,0 +1,53 @@
+#pragma once
+#include <string>
+
+namespace ki
+{
+namespace pclass
+{
+	template <
+		typename _Elem,
+		typename _Traits,
+		typename _Alloc
+	>
+	struct PrimitiveTypeWriter<std::basic_string<_Elem, _Traits, _Alloc>>
+	{
+	private:
+		using type = std::basic_string<_Elem, _Traits, _Alloc>;
+
+	public:
+		static void write_to(BitStream &stream, const type &value)
+		{
+			// Write the length as an unsigned short
+			stream.write<uint16_t>(value.length());
+
+			// Write each character as _Elem
+			for (auto it = value.begin(); it != value.end(); ++it)
+				stream.write<_Elem>(*it);
+		}
+	};
+
+	template <
+		typename _Elem,
+		typename _Traits,
+		typename _Alloc
+	>
+	struct PrimitiveTypeReader<std::basic_string<_Elem, _Traits, _Alloc>>
+	{
+	private:
+		using type = std::basic_string<_Elem, _Traits, _Alloc>;
+
+	public:
+		static void read_from(BitStream &stream, type &value)
+		{
+			// Read the length and create a new string with the correct capacity
+			auto length = stream.read<uint16_t>();
+			value = type(length, ' ');
+
+			// Read each character into the string
+			for (auto it = value.begin(); it != value.end(); ++it)
+				*it = stream.read<_Elem>();
+		}
+	};
+}
+}

include/ki/pclass/types/Type.h

@@ -4,42 +4,53 @@
 #include <map>
 #include "ki/pclass/HashCalculator.h"
 #include "ki/pclass/Value.h"
-#include "ki/pclass/PropertyClass.h"
 #include "ki/util/BitStream.h"
 
 namespace ki
 {
 namespace pclass
 {
+	class PropertyClass;
+
 	/**
-	 * TODO: Documentation
+	 * A base class for classes that represent a Type.
 	 */
 	class Type
 	{
 		friend class TypeSystem;
 
 	public:
-		/**
-		 * TODO: Documentation
-		 */
 		enum class kind
 		{
 			NONE,
+			
+			/**
+			 * A Type that contain pure, simple values.
+			 */
 			PRIMITIVE,
+
+			/**
+			 * A user-defined Type.
+			 */
 			CLASS,
+
+			/**
+			 * A data type consisting of a set of named values.
+			 */
 			ENUM
 		};
 
-		Type(std::string name, hash_t hash);
+		Type(const std::string &name, const TypeSystem &type_system);
-		virtual ~Type() {};
+		virtual ~Type() { }
 
 		std::string get_name() const;
 		hash_t get_hash() const;
 		kind get_kind() const;
+		const TypeSystem &get_type_system() const;
 
 		virtual PropertyClass *instantiate() const;
-		virtual void write_to(BitStream &stream, const Value &value) const = 0;
+		virtual void write_to(BitStream &stream, const Value &value) const;
-		virtual void read_from(BitStream &stream, Value &value) const = 0;
+		virtual void read_from(BitStream &stream, Value &value) const;
 
 	protected:
 		kind m_kind;
@@ -47,8 +58,13 @@ namespace pclass
 	private:
 		std::string m_name;
 		hash_t m_hash;
+		const TypeSystem &m_type_system;
 
-		void set_hash(hash_t hash);
+		/**
+		 * Called by a TypeSystem instance when it's HashCalculator
+		 * is changed.
+		 */
+		virtual void update_hash();
 	};
 
 	typedef std::vector<Type *> TypeList;

include/ki/util/FlagsEnum.h

@@ -0,0 +1,68 @@
+#pragma once
+#include <type_traits>
+
+#define MAKE_FLAGS_ENUM(n) \
+	template <> \
+	struct ki::is_flags_enum<n> : std::true_type {}
+
+#define SET_FLAG(v, f) v |= f
+#define UNSET_FLAG(v, f) v &= ~f
+#define FLAG_IS_SET(v, f) (v & f) == f
+
+namespace ki
+{
+	template <typename EnumT>
+	struct is_flags_enum : std::false_type {};
+
+	template <
+		typename EnumT,
+		typename = typename std::enable_if<is_flags_enum<EnumT>::value>::type
+	>
+	constexpr EnumT operator|(EnumT lhs, EnumT rhs)
+	{
+		using type = typename std::underlying_type<EnumT>::type;
+		return static_cast<EnumT>(
+			static_cast<type>(lhs) | static_cast<type>(rhs)
+		);
+	}
+
+	template <
+		typename EnumT,
+		typename = typename std::enable_if<is_flags_enum<EnumT>::value>::type
+	>
+	constexpr EnumT operator&(EnumT lhs, EnumT rhs)
+	{
+		using type = typename std::underlying_type<EnumT>::type;
+		return static_cast<EnumT>(
+			static_cast<type>(lhs) & static_cast<type>(rhs)
+		);
+	}
+
+	template <
+		typename EnumT,
+		typename = typename std::enable_if<is_flags_enum<EnumT>::value>::type
+	>
+	constexpr EnumT operator~(EnumT lhs)
+	{
+		using type = typename std::underlying_type<EnumT>::type;
+		return static_cast<EnumT>(~static_cast<type>(lhs));
+	}
+
+	template <
+		typename EnumT,
+		typename = typename std::enable_if<is_flags_enum<EnumT>::value>::type
+	>
+	EnumT &operator|=(EnumT &lhs, EnumT rhs)
+	{
+		return lhs = lhs | rhs;
+	}
+
+	template <
+		typename EnumT,
+		typename = typename std::enable_if<is_flags_enum<EnumT>::value>::type
+	>
+	EnumT &operator&=(EnumT &lhs, EnumT rhs)
+	{
+		return lhs = lhs & rhs;
+	}
+}

include/ki/util/exception.h

@@ -0,0 +1,12 @@
+#pragma once
+#include <stdexcept>
+
+namespace ki
+{
+	class runtime_error : public std::runtime_error
+	{
+	public:
+		explicit runtime_error(const std::string &message)
+			: std::runtime_error(message) {}
+	};
+}

src/pclass/CMakeLists.txt

@@ -1,6 +1,10 @@
 target_sources(${PROJECT_NAME}
 	PRIVATE
+		${PROJECT_SOURCE_DIR}/src/pclass/ClassType.cpp
 		${PROJECT_SOURCE_DIR}/src/pclass/HashCalculator.cpp
+		${PROJECT_SOURCE_DIR}/src/pclass/Property.cpp
+		${PROJECT_SOURCE_DIR}/src/pclass/PropertyClass.cpp
+		${PROJECT_SOURCE_DIR}/src/pclass/PropertyList.cpp
 		${PROJECT_SOURCE_DIR}/src/pclass/Type.cpp
 		${PROJECT_SOURCE_DIR}/src/pclass/TypeSystem.cpp
 )

src/pclass/ClassType.cpp

@@ -0,0 +1,44 @@
+#include "ki/pclass/types/ClassType.h"
+
+namespace ki
+{
+namespace pclass
+{
+	ClassTypeBase::ClassTypeBase(const std::string& name,
+		const Type* base_class, const TypeSystem& type_system)
+		: Type(name, type_system)
+	{
+		m_kind = kind::CLASS;
+
+		// Have we been given a base class?
+		if (base_class)
+		{
+			// Make sure the base class is a class type
+			if (base_class->get_kind() != kind::CLASS)
+				throw runtime_error("base_class must be a class type!");
+
+			// Cast the base class up to a ClassTypeBase pointer
+			m_base_class = dynamic_cast<const ClassTypeBase *>(base_class);
+			if (!m_base_class)
+				throw runtime_error("base_class must inherit ClassTypeBase!");
+		}
+	}
+
+	bool ClassTypeBase::inherits(const Type &type) const
+	{
+		// Types do not technically inherit from themselves, but it is more useful
+		// if they report that they do since these checks are to make sure that objects
+		// have a common interface
+		if (&type == this)
+			return true;
+
+		// If we have a base class, go down the inheritance tree and see if our
+		// ancestors inherit from the requested type
+		if (m_base_class)
+			return m_base_class->inherits(type);
+
+		// We've reached the bottom of the inheritance tree; there is no inheritance.
+		return false;
+	}
+}
+}

src/pclass/HashCalculator.cpp

@@ -1,4 +1,5 @@
 #include "ki/pclass/HashCalculator.h"
+#include <string>
 
 namespace ki
 {
@@ -35,16 +36,13 @@ namespace pclass
 		return result;
 	}
 
-	hash_t WizardHashCalculator::calculate_property_hash(const std::string& name, const hash_t type_hash) const
+	hash_t WizardHashCalculator::calculate_property_hash(const std::string& name) const
 	{
 		// Find the hash of the property name
 		hash_t result = 0x1505;
 		for (auto it = name.begin(); it != name.end(); ++it)
 			result = (0x21 * result) + *it;
-		result &= 0x7FFFFFFF;
+		return result & 0x7FFFFFFF;
-
-		// Add the type hash onto it
-		return result + type_hash;
 	}
 }
 }

src/pclass/Property.cpp

@@ -0,0 +1,88 @@
+#include "ki/pclass/Property.h"
+#include "ki/pclass/PropertyClass.h"
+#include "ki/pclass/TypeSystem.h"
+#include "ki/util/exception.h"
+
+namespace ki
+{
+namespace pclass
+{
+	PropertyBase::PropertyBase(PropertyClass &object,
+		const std::string &name, const Type &type)
+	{
+		m_name = name;
+		m_name_hash = type
+			.get_type_system()
+			.get_hash_calculator()
+			.calculate_property_hash(name);
+		m_full_hash = m_name_hash + type.get_hash();
+		m_type = &type;
+
+		// Add this property to the object's property list
+		object.get_properties().add_property(this);
+	}
+
+	std::string PropertyBase::get_name() const
+	{
+		return m_name;
+	}
+
+	hash_t PropertyBase::get_name_hash() const
+	{
+		return m_name_hash;
+	}
+
+	hash_t PropertyBase::get_full_hash() const
+	{
+		return m_full_hash;
+	}
+
+	const Type &PropertyBase::get_type() const
+	{
+		return *m_type;
+	}
+
+	bool PropertyBase::is_pointer() const
+	{
+		return false;
+	}
+
+	bool PropertyBase::is_dynamic() const
+	{
+		return false;
+	}
+
+	DynamicPropertyBase::DynamicPropertyBase(PropertyClass &object,
+		const std::string& name, const Type& type)
+		: PropertyBase(object, name, type) { }
+
+	bool DynamicPropertyBase::is_dynamic() const
+	{
+		return true;
+	}
+
+	Value DynamicPropertyBase::get_value() const
+	{
+		// The caller must specify an index
+		throw runtime_error("Called get_value() on a dynamic property. Use get_value(index) instead.");
+	}
+
+	const PropertyClass *DynamicPropertyBase::get_object() const
+	{
+		// The caller must specify an index
+		throw runtime_error("Called get_object() on a dynamic property. Use get_object(index) instead.");
+	}
+
+	void DynamicPropertyBase::write_value_to(BitStream &stream) const
+	{
+		// The caller must specify an index
+		throw runtime_error("Called write_value_to() on a dynamic property. Use write_value_to(index) instead.");
+	}
+
+	void DynamicPropertyBase::read_value_from(BitStream &stream)
+	{
+		// The caller must specify an index
+		throw runtime_error("Called read_value_from() on a dynamic property. Use read_value_from(index) instead.");
+	}
+}
+}

src/pclass/PropertyClass.cpp

@@ -0,0 +1,34 @@
+#include "ki/pclass/PropertyClass.h"
+
+namespace ki
+{
+namespace pclass
+{
+	PropertyClass::PropertyClass(const Type &type, const TypeSystem &type_system)
+	{
+		m_type = &type;
+		m_properties = new PropertyList();
+	}
+
+	PropertyClass::~PropertyClass()
+	{
+		// Delete the list of properties
+		delete m_properties;
+	}
+
+	const Type& PropertyClass::get_type() const
+	{
+		return *m_type;
+	}
+
+	PropertyList &PropertyClass::get_properties()
+	{
+		return *m_properties;
+	}
+
+	const PropertyList& PropertyClass::get_properties() const
+	{
+		return *m_properties;
+	}
+}
+}

src/pclass/PropertyList.cpp

@@ -0,0 +1,107 @@
+#include "ki/pclass/PropertyList.h"
+#include "ki/pclass/Property.h"
+#include "ki/util/exception.h"
+#include <sstream>
+#include <iomanip>
+
+namespace ki
+{
+namespace pclass
+{
+	std::size_t PropertyList::get_property_count() const
+	{
+		return m_properties.size();
+	}
+
+	bool PropertyList::has_property(const std::string& name) const
+	{
+		return m_property_name_lookup.find(name)
+			!= m_property_name_lookup.end();
+	}
+
+	bool PropertyList::has_property(const hash_t hash) const
+	{
+		return m_property_hash_lookup.find(hash)
+			!= m_property_hash_lookup.end();
+	}
+
+	const PropertyBase& PropertyList::get_property(const int index) const
+	{
+		if (index >= 0 && index < m_properties.size())
+			return *m_properties[index];
+
+		std::ostringstream oss;
+		oss << "Property index out of range. (index=" << index
+			<< ", size=" << m_properties.size() << ")";
+		throw runtime_error(oss.str());
+	}
+
+	const PropertyBase& PropertyList::get_property(const std::string& name) const
+	{
+		const auto it = m_property_name_lookup.find(name);
+		if (it != m_property_name_lookup.end())
+			return *it->second;
+
+		std::ostringstream oss;
+		oss << "Could not find property with name: '" << name << "'.";
+		throw runtime_error(oss.str());
+	}
+
+	const PropertyBase& PropertyList::get_property(const hash_t hash) const
+	{
+		const auto it = m_property_hash_lookup.find(hash);
+		if (it != m_property_hash_lookup.end())
+			return *it->second;
+
+		std::ostringstream oss;
+		oss << "Could not find property with hash: 0x"
+			<< std::hex << std::setw(8) << std::setfill('0')
+			<< std::uppercase << hash << ".";
+		throw runtime_error(oss.str());
+	}
+
+	PropertyList::const_iterator PropertyList::begin() const
+	{
+		return m_properties.cbegin();
+	}
+
+	PropertyList::const_iterator PropertyList::end() const
+	{
+		return m_properties.cend();
+	}
+
+	void PropertyList::add_property(PropertyBase *prop)
+	{
+		// Make sure a property with the same name as another isn't being added
+		if (has_property(prop->get_name()))
+		{
+			// This pointer is going to be lost, so delete it now
+			delete prop;
+
+			std::ostringstream oss;
+			oss << "A property has already been added with name: '"
+				<< prop->get_name() << "'.";
+			throw runtime_error(oss.str());
+		}
+
+		// Check for hash collisions
+		if (has_property(prop->get_full_hash()))
+		{
+			const auto &other = get_property(prop->get_full_hash());
+
+			// This pointer is going to be lost, so delete it now
+			delete prop;
+
+			std::ostringstream oss;
+			oss << "Cannot add property '" << prop->get_name() << "'. "
+				<< "Hash collision with property '" << other.get_name() << "'.";
+			throw runtime_error(oss.str());
+		}
+
+		// Add the property to lookups
+		m_properties.push_back(prop);
+		m_property_name_lookup[prop->get_name()] = prop;
+		m_property_hash_lookup[prop->get_full_hash()] = prop;
+	}
+}
+}

src/pclass/Type.cpp

@@ -1,4 +1,6 @@
-#include "ki/pclass/Type.h"
+#include "ki/pclass/types/Type.h"
+#include "ki/pclass/TypeSystem.h"
+#include "ki/util/exception.h"
 #include <stdexcept>
 #include <sstream>
 
@@ -6,10 +8,13 @@ namespace ki
 {
 namespace pclass
 {
-	Type::Type(const std::string name, const hash_t hash)
+	Type::Type(const std::string &name, const TypeSystem &type_system)
+		: m_type_system(type_system)
 	{
 		m_name = name;
-		m_hash = hash;
+		m_hash = m_type_system
+			.get_hash_calculator()
+			.calculate_type_hash(name);
 		m_kind = kind::NONE;
 	}
 
@@ -18,11 +23,6 @@ namespace pclass
 		return m_name;
 	}
 
-	void Type::set_hash(const hash_t hash)
-	{
-		m_hash = hash;
-	}
-
 	hash_t Type::get_hash() const
 	{
 		return m_hash;
@@ -33,11 +33,37 @@ namespace pclass
 		return m_kind;
 	}
 
+	const TypeSystem &Type::get_type_system() const
+	{
+		return m_type_system;
+	}
+
+	void Type::write_to(BitStream& stream, const Value& value) const
+	{
+		std::ostringstream oss;
+		oss << "Type '" << m_name << "' does not implement Type::write_to.";
+		throw runtime_error(oss.str());
+	}
+
+	void Type::read_from(BitStream& stream, Value& value) const
+	{
+		std::ostringstream oss;
+		oss << "Type '" << m_name << "' does not implement Type::read_from.";
+		throw runtime_error(oss.str());
+	}
+
 	PropertyClass *Type::instantiate() const
 	{
 		std::ostringstream oss;
-		oss << "Type '" << m_name << "' cannot be instantiated.";
+		oss << "Type '" << m_name << "' does not implement Type::instantiate.";
-		throw std::runtime_error(oss.str());
+		throw runtime_error(oss.str());
+	}
+
+	void Type::update_hash()
+	{
+		m_hash = m_type_system
+			.get_hash_calculator()
+			.calculate_type_hash(m_name);
 	}
 }
 }

src/pclass/TypeSystem.cpp

@@ -1,4 +1,6 @@
 #include "ki/pclass/TypeSystem.h"
+#include "ki/util/BitTypes.h"
+#include "ki/util/exception.h"
 #include <sstream>
 #include <iomanip>
 
@@ -21,14 +23,6 @@ namespace ki
 {
 namespace pclass
 {
-	TypeSystem& TypeSystem::get_singleton()
-	{
-		if (s_instance == nullptr)
-			// Create the static instance with the default hash calculator
-			s_instance = new TypeSystem(new WizardHashCalculator());
-		return *s_instance;
-	}
-
 	TypeSystem::TypeSystem(HashCalculator *hash_calculator)
 	{
 		m_hash_calculator = hash_calculator;
@@ -69,8 +63,12 @@ namespace pclass
 		define_primitive<float>("float");
 		define_primitive<double>("double");
 
-		// TODO: Define bit floating point types
+		// Define string types
-		// TODO: Define string types
+		define_primitive<std::string>("std::string");
+		define_primitive<std::wstring>("std::wstring");
+
+		// Define the base class for all classes
+		define_class<PropertyClass>("class PropertyClass");
 	}
 
 	TypeSystem::~TypeSystem()
@@ -87,6 +85,15 @@ namespace pclass
 		delete m_hash_calculator;
 	}
 
+	const HashCalculator &TypeSystem::get_hash_calculator() const
+	{
+		// Make sure the hash calculator isn't null
+		if (m_hash_calculator == nullptr)
+			throw runtime_error("TypeSystem::get_hash_calculator() called but hash calculator is null.");
+
+		return *m_hash_calculator;
+	}
+
 	void TypeSystem::set_hash_calculator(HashCalculator* hash_calculator)
 	{
 		// Update the hash calculator
@@ -96,46 +103,47 @@ namespace pclass
 		m_type_hash_lookup.clear();
 		for (auto it = m_types.begin(); it != m_types.end(); ++it)
 		{
-			// Calculate the new hash and update the type
-			auto *type = *it;
-			const auto new_hash = m_hash_calculator->calculate_type_hash(type->get_name());
-			type->set_hash(new_hash);
-
 			// Add the new hash to lookup
-			m_type_hash_lookup[new_hash] = type;
+			auto *type = *it;
+			type->update_hash();
+			m_type_hash_lookup[type->get_hash()] = type;
+		}
+	}
 
-			// Is this type a class?
+	bool TypeSystem::has_type(const std::string &name) const
-			if (type->get_kind() == Type::kind::CLASS)
 	{
-				// TODO: Recalculate property hashes
+		return m_type_name_lookup.find(name) != m_type_name_lookup.end();
-			}
-		}
 	}
 
-	Type& TypeSystem::get_type(const std::string &name) const
+	bool TypeSystem::has_type(const hash_t hash) const
+	{
+		return m_type_hash_lookup.find(hash) != m_type_hash_lookup.end();
+	}
+
+	const Type &TypeSystem::get_type(const std::string &name) const
 	{
 		const auto it = m_type_name_lookup.find(name);
 		if (it == m_type_name_lookup.end())
 		{
 			std::ostringstream oss;
 			oss << "Could not find type with name '" << name << "'.";
-			throw std::runtime_error(oss.str());
+			throw runtime_error(oss.str());
 		}
-		return *(it->second);
+		return *it->second;
 	}
 
-	Type& TypeSystem::get_type(const hash_t hash) const
+	const Type &TypeSystem::get_type(const hash_t hash) const
 	{
 		const auto it = m_type_hash_lookup.find(hash);
 		if (it == m_type_hash_lookup.end())
 		{
 			std::ostringstream oss;
-			oss << "Could not find type with hash: " <<
+			oss << "Could not find type with hash: 0x" <<
 				std::hex << std::setw(8) << std::setfill('0') <<
 				std::uppercase << hash << ".";
-			throw std::runtime_error(oss.str());
+			throw runtime_error(oss.str());
 		}
-		return *(it->second);
+		return *it->second;
 	}
 
 	void TypeSystem::define_type(Type *type)
@@ -149,7 +157,7 @@ namespace pclass
 			// Throw an error
 			std::ostringstream oss;
 			oss << "Type '" << type->get_name() << "' is already defined.";
-			throw std::runtime_error(oss.str());
+			throw runtime_error(oss.str());
 		}
 
 		// Does a type with this hash already exist?
@@ -163,7 +171,7 @@ namespace pclass
 			std::ostringstream oss;
 			oss << "Type hash collision between '" << type->get_name()
 				<< "' and '" << other_type.get_name() << "'.";
-			throw std::runtime_error(oss.str());
+			throw runtime_error(oss.str());
 		}
 
 		// This type is safe to add to our lookups