text: /*
   * Copyright (c) 2011-2021, The DART development contributors
   * All rights reserved.
   *
   * The list of contributors can be found at:
   *   https://github.com/dartsim/dart/blob/main/LICENSE
   *
   * This file is provided under the following "BSD-style" License:
   *   Redistribution and use in source and binary forms, with or
   *   without modification, are permitted provided that the following
   *   conditions are met:
   *   * Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   *   * Redistributions in binary form must reproduce the above
   *     copyright notice, this list of conditions and the following
   *     disclaimer in the documentation and/or other materials provided
   *     with the distribution.
   *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   *   CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
   *   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   *   MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   *   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
   *   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   *   USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   *   AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   *   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   *   ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   *   POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef DART_COMMON_REQUIRESASPECT_HPP_
  #define DART_COMMON_REQUIRESASPECT_HPP_
  
  #include "dart/common/ClassWithVirtualBase.hpp"
  #include "dart/common/SpecializedForAspect.hpp"
  
  namespace dart {
  namespace common {
  
  //==============================================================================
  /// RequiresAspect allows classes that inherit Composite to know which Aspects
  /// are required for their operation. This guarantees that there is no way for
  /// a required Aspect do not get unexpectedly removed from their composite.
  ///
  /// Required Aspects are also automatically specialized for.
  template <class... OtherRequiredAspects>
  class RequiresAspect
  {
  };
  
  //==============================================================================
  DART_DECLARE_CLASS_WITH_VIRTUAL_BASE_BEGIN
  template <class ReqAspect>
  class RequiresAspect<ReqAspect> : public virtual SpecializedForAspect<ReqAspect>
  {
  public:
    /// Default constructor. This is where the base Composite is informed that
    /// the Aspect type is required.
    RequiresAspect();
  };
  DART_DECLARE_CLASS_WITH_VIRTUAL_BASE_END
  
  //==============================================================================
  template <class ReqAspect1, class... OtherReqAspects>
  class RequiresAspect<ReqAspect1, OtherReqAspects...>
    : public CompositeJoiner<
          Virtual<RequiresAspect<ReqAspect1> >,
          Virtual<RequiresAspect<OtherReqAspects...> > >
  {
  };
  
  } // namespace common
  } // namespace dart
  
  #include "dart/common/detail/RequiresAspect.hpp"
  
  #endif // DART_COMMON_REQUIRESASPECT_HPP_
  