daw_writable_output_ostream.h

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// Copyright (c) Darrell Wright
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/beached/daw_json_link
//
 
#pragma once
 
#include "daw/json/impl/version.h"
 
#include "daw/json/concepts/daw_writable_output_fwd.h"
#include "daw/json/impl/daw_json_assert.h"
 
#include <daw/daw_algorithm.h>
#include <daw/daw_character_traits.h>
#include <daw/daw_enable_requires.h>
 
#include <iostream>
 
namespace daw::json {
  inline namespace DAW_JSON_VER {
    namespace concepts {
      template<typename T>
      DAW_REQUIRES( std::is_base_of_v<std::ostream, T> )
      struct writable_output_trait<T DAW_ENABLEIF_S(
        std::is_base_of_v<std::ostream, T> )> : std::true_type {
 
        template<typename... StringViews>
        static void write( std::ostream &os, StringViews const &...svs ) {
          static_assert( sizeof...( StringViews ) > 0 );
          DAW_CPP23_STATIC_LOCAL constexpr auto writer =
            []( std::ostream &o, auto sv ) DAW_JSON_CPP23_STATIC_CALL_OP {
              if( sv.empty( ) ) {
                return 0;
              }
              o.write( sv.data( ), static_cast<std::streamsize>( sv.size( ) ) );
              daw_json_ensure( static_cast<bool>( o ),
                               daw::json::ErrorReason::OutputError );
              return 1;
            };
          ( (void)writer( os, svs ), ... );
        }
 
        static void put( std::ostream &os, char c ) {
          os.put( c );
          daw_json_ensure( static_cast<bool>( os ),
                           daw::json::ErrorReason::OutputError );
        }
      };
    } // namespace concepts
  } // namespace DAW_JSON_VER
} // namespace daw::json