overload.h

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/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2021 John Wellbelove
 
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#ifndef ETL_OVERLOAD_INCLUDED
#define ETL_OVERLOAD_INCLUDED
 
#include "platform.h"
#include "type_traits.h"
#include "utility.h"
 
namespace etl
{
#if ETL_USING_CPP17
  //*************************************************************************
  //*************************************************************************
  template <typename... TOverloads>
  struct overload : TOverloads...
  {
    using TOverloads::operator()...;
  };
 
  //*************************************************************************
  //*************************************************************************
  template <typename... TOverloads>
  overload(TOverloads...) -> overload<TOverloads...>;
 
  //*************************************************************************
  //*************************************************************************
  template <typename... TOverloads>
  constexpr overload<TOverloads...> make_overload(TOverloads&&... overloads)
  {
    return overload<TOverloads...>{etl::forward<TOverloads>(overloads)...};
  }
#elif ETL_USING_CPP11
  //*************************************************************************
  //*************************************************************************
  template <typename... TRest>
  struct overload;
 
  //*************************************************************************
  //*************************************************************************
  template <typename TOverload, typename... TRest>
  struct overload<TOverload, TRest...>
    : TOverload
    , overload<TRest...>
  {
    overload(TOverload first, TRest... rest)
      : TOverload(first)
      , overload<TRest...>(rest...)
    {
    }
 
    using TOverload::operator();
    using overload<TRest...>::operator();
  };
 
  //*************************************************************************
  //*************************************************************************
  template <typename TOverload>
  struct overload<TOverload> : TOverload
  {
    overload(TOverload first)
      : TOverload(first)
    {
    }
 
    using TOverload::operator();
  };
 
  //*************************************************************************
  //*************************************************************************
  template <typename... TRest>
  overload<TRest...> make_overload(TRest... overloads)
  {
    return overload<TRest...>(overloads...);
  }
#endif
} // namespace etl
 
#endif