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[ceph.git] / ceph / src / boost / boost / outcome / experimental / status-code / iostream_support.hpp

/* Proposed SG14 status_code
(C) 2018-2019 Niall Douglas <http://www.nedproductions.biz/> (5 commits)
File Created: Feb 2018


Boost Software License - Version 1.0 - August 17th, 2003

Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
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The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
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*/

#ifndef BOOST_OUTCOME_SYSTEM_ERROR2_IOSTREAM_SUPPORT_HPP
#define BOOST_OUTCOME_SYSTEM_ERROR2_IOSTREAM_SUPPORT_HPP

#include "error.hpp"

#include <iostream>

BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_BEGIN

/*! Print the status code to a `std::ostream &`.
Requires that `DomainType::value_type` implements an `operator<<` overload for `std::ostream`.
*/
template <class DomainType,  //
          typename std::enable_if<std::is_same<std::ostream, typename std::decay<decltype(std::declval<std::ostream>() << std::declval<typename status_code<DomainType>::value_type>())>::type>::value, bool>::type = true>
inline std::ostream &operator<<(std::ostream &s, const status_code<DomainType> &v)
{
  if(v.empty())
  {
    return s << "(empty)";
  }
  return s << v.domain().name().c_str() << ": " << v.value();
}

/*! Print the erased status code to a `std::ostream &`.
*/
template <class ErasedType> inline std::ostream &operator<<(std::ostream &s, const status_code<erased<ErasedType>> &v)
{
  if(v.empty())
  {
    return s << "(empty)";
  }
  return s << v.domain().name().c_str() << ": " << v.message().c_str();
}

/*! Print the generic code to a `std::ostream &`.
*/
inline std::ostream &operator<<(std::ostream &s, const generic_code &v)
{
  if(v.empty())
  {
    return s << "(empty)";
  }
  return s << v.domain().name().c_str() << ": " << v.message().c_str();
}

BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_END

#endif