EntityMetaData.hpp

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 * Copyright 2023 51 Degrees Mobile Experts Limited, Davidson House,
 * Forbury Square, Reading, Berkshire, United Kingdom RG1 3EU.
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#ifndef FIFTYONE_DEGREES_ENTITY_META_DATA_HPP
#define FIFTYONE_DEGREES_ENTITY_META_DATA_HPP

#include <string>
#include <vector>
#include "data.h"

using std::vector;
using std::string;

namespace FiftyoneDegrees {
	namespace Common {
		/**
		 * Base class for any entity meta data. All meta data classes should
		 * extend this class.
		 *
		 * A meta data instance is immutable once it has been instantiated. An
		 * instance is also comparable to another via the `==` and `!=`
		 * operators, provided the type K is properly implemented.
		 * @tparam K key type for the entity which must be unique e.g. string
		 * is used for property meta data where the unique key is the name of
		 * the property. The type K must implement the `<` and `==` operators.
		 */
		template <class K> class EntityMetaData {
		public:
			/**
			 * @name Constructors
			 * @{
			 */

			/**
			 * Construct a new instance with the key provided.
			 * @param key of type K
			 */
			EntityMetaData(K key) { this->key = key; }

			/**
			 * @}
			 * @name Getters
			 * @{
			 */

			/**
			 * Get the unique key for this entity instance.
			 * @return key of type K
			 */
			K getKey() const { return key; }

			/**
			 * @}
			 * @name Operators
			 * @{
			 */

			/**
			 * Returns true is the two entities share the same unique key.
			 * @param other the other instance to compare
			 * @return true if they are equal
			 */
			const bool operator== (const EntityMetaData<K> other) const {
				return other.key == key;
			}

			/**
			 * Returns true is the two entities do not share the same unique
			 * key.
			 * @param other the other instance to compare
			 * @return true if they are not equal
			 */
			const bool operator!= (const EntityMetaData<K> other) const {
				return !(other.key == key);
			}

			/**
			 * @}
			 */
		private:
			/** The unique key for this instance. */
			K key;
		};
	}
}

#endif