text: // MIT License
  //
  // Copyright (c) 2018 Oscar B.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in all
  // copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  // SOFTWARE.
  #ifndef NON_GRAVITAR_SOLAR_SYSTEM_HPP
  #define NON_GRAVITAR_SOLAR_SYSTEM_HPP
  
  #include <forward_list>
  #include <memory>
  #include "shape/Planet.hpp"
  #include "shape/SpawnArea.hpp"
  #include "CollisionGroup.hpp"
  
  
  namespace gvt {
  	class SolarSystem: public CollisionGroup {
  		private:
  			shared_ptr<SpawnArea> mSpawnArea;
  			std::forward_list<shared_ptr<Planet>> mPlanets;
  
  			/**
  			 * Updates height, width and mPlanets values upon insertion of a new
  			 * @c Shape.
  			 */
  			void onInsertShape (shared_ptr<Shape> shape) override;
  			/**
  			 * Updates height, width and mPlanets values upon removal of an old
  			 * @c Shape.
  			 */
  			void onRemoveShape (shared_ptr<Shape> shape) override;
  		public:
  			using iterator = std::forward_list<shared_ptr<Planet>>::iterator;
  
  			inline shared_ptr<SpawnArea> spawnArea() const;
  			/**
  			 * @return The begin iterator of the planets list.
  			 */
  			inline iterator planetsBegin();
  			/**
  			 * @return The end iterator of the planets list.
  			 */
  			inline iterator planetsEnd();
  	};
  }
  
  
  namespace gvt {
  	shared_ptr<SpawnArea> SolarSystem::spawnArea() const {
  		return mSpawnArea;
  	}
  
  	SolarSystem::iterator SolarSystem::planetsBegin() {
  		return mPlanets.begin();
  	}
  
  	SolarSystem::iterator SolarSystem::planetsEnd() {
  		return mPlanets.end();
  	}
  }
  
  
  #endif