boxed_cast.hpp

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// This file is distributed under the BSD License.
// See "license.txt" for details.
// Copyright 2009-2012, Jonathan Turner (jonathan@emptycrate.com)
// Copyright 2009-2017, Jason Turner (jason@emptycrate.com)
// http://www.chaiscript.com
 
// This is an open source non-commercial project. Dear PVS-Studio, please check it.
// PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
 
 
#ifndef CHAISCRIPT_BOXED_CAST_HPP_
#define CHAISCRIPT_BOXED_CAST_HPP_
 
#include "../chaiscript_defines.hpp"
#include "bad_boxed_cast.hpp"
#include "boxed_cast_helper.hpp"
#include "boxed_value.hpp"
#include "type_conversions.hpp"
#include "type_info.hpp"
 
namespace chaiscript {
class Type_Conversions;
namespace detail {
namespace exception {
class bad_any_cast;
}  // namespace exception
}  // namespace detail
}  // namespace chaiscript
 
namespace chaiscript 
{
 
  template<typename Type>
  decltype(auto) boxed_cast(const Boxed_Value &bv, const Type_Conversions_State *t_conversions = nullptr)
  {
    if (!t_conversions || bv.get_type_info().bare_equal(user_type<Type>()) || (t_conversions && !(*t_conversions)->convertable_type<Type>())) {
      try {
        return(detail::Cast_Helper<Type>::cast(bv, t_conversions));
      } catch (const chaiscript::detail::exception::bad_any_cast &) {
      }
    }
 
 
    if (t_conversions && (*t_conversions)->convertable_type<Type>())
    {
      try {
        // We will not catch any bad_boxed_dynamic_cast that is thrown, let the user get it
        // either way, we are not responsible if it doesn't work
        return(detail::Cast_Helper<Type>::cast((*t_conversions)->boxed_type_conversion<Type>(t_conversions->saves(), bv), t_conversions));
      } catch (...) {
        try {
          // try going the other way
          return(detail::Cast_Helper<Type>::cast((*t_conversions)->boxed_type_down_conversion<Type>(t_conversions->saves(), bv), t_conversions));
        } catch (const chaiscript::detail::exception::bad_any_cast &) {
          throw exception::bad_boxed_cast(bv.get_type_info(), typeid(Type));
        }
      }
    } else {
      // If it's not convertable, just throw the error, don't waste the time on the 
      // attempted dynamic_cast
      throw exception::bad_boxed_cast(bv.get_type_info(), typeid(Type));
    }
 
  }
 
}
 
 
 
#endif