disposables

disposables.cs

interface IFooRepository : IDisposable
{
	Foo GetFoo();
}

interface IFooRepositoryFactory
{
	IFooRepository Create(DisposableCollection disposables);
}

class LoggingFooRepositoryFactory 
{
	ILoggerFactory LoggerFactory;
	IFooRepositoryFactory InnerFactory;

	IFooRepository Create()
	{
		// n+m disposables!
		var logger = LoggerFactory.Create();
		var inner = InnerFactory.Create();
		return new LoggingFooRepository(logger, inner);
	}
}

class LoggingFooRepository : IFooRepository {
	void Dispose
	{
		_logger.Dispose();
		_inner.Dispose();
	}
}

class MemoryFooRepositoryFactory
{
	IFooRepository Create(DisposableCollection disposables)
	{
		// no disposables!
		return new MemoryFooRepository();
	}
}

class SingletonFooRepositoryFactory
{
	// this is a pre-stored instance of Some Type, not a particular one
	public IFooRepository Instance;

	IFooRepository Create(DisposableCollection disposables)
	{
		// no disposables, and also you shouldn't dispose even the return value
		return Instance;
	}
}