.. _program_listing_file_mcfp_error.hpp:

Program Listing for File error.hpp
==================================

|exhale_lsh| :ref:`Return to documentation for file <file_mcfp_error.hpp>` (``mcfp/error.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   /*-
    * SPDX-License-Identifier: BSD-2-Clause
    *
    * Copyright (c) 2022-2025 Maarten L. hekkelman
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions are met:
    *
    * 1. Redistributions of source code must retain the above copyright notice, this
    *    list of conditions and the following disclaimer
    * 2. 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 OWNER 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.
    */
   
   #pragma once
   
   #include <cassert>
   #include <string>
   #include <system_error>
   
   namespace mcfp
   {
   
   // we use the new system_error stuff.
   
   enum class config_error
   {
       unknown_option = 1,              
       option_does_not_accept_argument, 
       missing_argument_for_option,     
       option_not_specified,            
       invalid_config_file,             
       wrong_type_cast,                 
       config_file_not_found            
   };
   class config_category_impl : public std::error_category
   {
     public:
       const char *name() const noexcept override
       {
           return "configuration";
       }
   
       std::string message(int ev) const override
       {
           switch (static_cast<config_error>(ev))
           {
               case config_error::unknown_option:
                   return "unknown option";
               case config_error::option_does_not_accept_argument:
                   return "option does not accept argument";
               case config_error::missing_argument_for_option:
                   return "missing argument for option";
               case config_error::option_not_specified:
                   return "option was not specified";
               case config_error::invalid_config_file:
                   return "config file contains a syntax error";
               case config_error::wrong_type_cast:
                   return "the implementation contains a type cast error";
               case config_error::config_file_not_found:
                   return "the specified config file was not found";
               default:
                   assert(false);
                   return "unknown error code";
           }
       }
   
       bool equivalent(const std::error_code & /*code*/, int /*condition*/) const noexcept override
       {
           return false;
       }
   };
   
   inline std::error_category &config_category()
   {
       static config_category_impl instance;
       return instance;
   }
   
   inline std::error_code make_error_code(config_error e)
   {
       return std::error_code(static_cast<int>(e), config_category());
   }
   
   inline std::error_condition make_error_condition(config_error e)
   {
       return std::error_condition(static_cast<int>(e), config_category());
   }
   
   } // namespace mcfp