defs-manager.hpp

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/*
  DEFS-MANAGER.hpp  -  access to preconfigured default objects and definitions

   Copyright (C)
     2008,            Hermann Vosseler <Ichthyostega@web.de>

  **Lumiera** is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version. See the file COPYING for further details.

*/


#ifndef LUMIERA_QUERY_DEFS_MANAGER_H
#define LUMIERA_QUERY_DEFS_MANAGER_H


#include "lib/p.hpp"
#include "lib/nocopy.hpp"
#include "common/query.hpp"

#include <memory>



namespace lumiera{
namespace query  {
  
  
  using lumiera::Query;
  using std::unique_ptr;
  
  namespace impl { class DefsRegistry; }
  
  
  class DefsManager
    : util::NonCopyable
    {
      unique_ptr<impl::DefsRegistry> defsRegistry_;
      
    public:
      
      DefsManager ()  noexcept;
     ~DefsManager ();
      
      template<class TAR>
      lib::P<TAR> operator() (Query<TAR> const&);
      
      
      template<class TAR>
      lib::P<TAR> search  (Query<TAR> const&);
      
      template<class TAR>
      lib::P<TAR> create  (Query<TAR> const&);
      
      template<class TAR>
      bool define  (lib::P<TAR> const&, Query<TAR> const&  =Query<TAR>());
      
      template<class TAR>
      bool forget  (lib::P<TAR> const&);
      
      
      void clear();
      
      
// Q: can we have something along the line of...?
//
//        template
//          < class TAR,                   ///< the target to query for 
//            template <class> class SMP  ///<  smart pointer class to wrap the result
//          >
//        SMP<TAR> operator() (const lumiera::Query<TAR>&);

// 12/09: according to my current knowledge of template metaprogramming, the answer is "no",
//        but we could use a traits template to set up a fixed association of smart pointers
//        and kinds of target object. This would allow to define a templated operator() returning
//        the result wrapped into the right holder. But currently I don't see how to build a sensible
//        implementation infrastructure backing such an interface.
      
    };
  
  
  
}} // namespace lumiera::query
#endif