ToolVisitor.h

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/***********************************************************************************\
* (c) Copyright 1998-2019 CERN for the benefit of the LHCb and ATLAS collaborations *
*                                                                                   *
* This software is distributed under the terms of the Apache version 2 licence,     *
* copied verbatim in the file "LICENSE".                                            *
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* In applying this licence, CERN does not waive the privileges and immunities       *
* granted to it by virtue of its status as an Intergovernmental Organization        *
* or submit itself to any jurisdiction.                                             *
\***********************************************************************************/
#pragma once
 
#include "GaudiKernel/IAlgTool.h"
#include <functional>
#include <regex>
#include <type_traits>
 
class ToolVisitor {
  struct IVisitor {
    virtual ~IVisitor()                   = default;
    virtual void visit( IAlgTool* ) const = 0;
  };
 
public:
  template <typename Callable, typename = std::enable_if_t<std::is_invocable_r_v<void, Callable, IAlgTool*>>>
  static void visit( const std::vector<IAlgTool*>& tools, Callable& callable,
                     const std::regex& reject_filter = s_noFilter ) {
    class Visitor final : public IVisitor {
      Callable* m_func;
 
    public:
      Visitor( Callable* f ) : m_func{ f } {}
      void visit( IAlgTool* alg_tool ) const override { std::invoke( *m_func, alg_tool ); }
    };
    recursiveVisit( tools, Visitor{ &callable }, reject_filter );
  }
 
private:
  static void             recursiveVisit( const std::vector<IAlgTool*>& tools, IVisitor const& visitor,
                                          const std::regex& reject_filter );
  static const std::regex s_noFilter;
};