no_substitution.h

Go to the documentation of this file.

// Author(s): Wieger Wesselink
// Copyright: see the accompanying file COPYING or copy at
// https://github.com/mCRL2org/mCRL2/blob/master/COPYING
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
/// \file mcrl2/data/substitutions/no_substitution.h
/// \brief add your file description here.
 
#ifndef MCRL2_DATA_SUBSTITUTIONS_NO_SUBSTITUTION_H
#define MCRL2_DATA_SUBSTITUTIONS_NO_SUBSTITUTION_H
 
#include <iostream>
#include "mcrl2/data/variable.h"
 
namespace mcrl2::data
{
 
/// \brief An empty struct that is used to denote the absence of a substitution.
/// Used for rewriters.
struct no_substitution
{
  static constexpr bool is_identity_substitution=true;
 
  /* static constexpr bool is_trivial()
  {
    return true;
  } */
 
  const variable& operator()(const variable& v) const
  {
    return v;
  }
};
 
inline
std::ostream& operator<<(std::ostream& out, const no_substitution&)
{
  return out << "[]";
}
 
} // namespace mcrl2::data
 
#endif // MCRL2_DATA_SUBSTITUTIONS_NO_SUBSTITUTION_H