daw_writable_output_fwd.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/daw_traits.h>
 
#include <cstddef>
#include <type_traits>
#include <utility>
 
namespace daw::json {
  inline namespace DAW_JSON_VER {
    namespace concepts {
      template<typename, typename = void>
      struct writable_output_trait : std::false_type {};
 
      template<typename T>
      DAW_CPP20_CONCEPT is_writable_output_type_v =
        writable_output_trait<T>::value;
    } // namespace concepts
 
    template<typename WritableOutput, typename... StringViews>
    constexpr WritableOutput &write_output( WritableOutput &out,
                                            StringViews const &...svs ) {
      concepts::writable_output_trait<WritableOutput>::write( out, svs... );
      return out;
    }
 
    template<typename WritableOutput, typename CharT>
    constexpr WritableOutput &put_output( WritableOutput &out, CharT c ) {
      concepts::writable_output_trait<WritableOutput>::put( out, c );
      return out;
    }
 
    namespace concepts {
      template<typename WritableOutput, typename = void>
      inline constexpr bool has_output_reserve_v = false;
 
      template<typename WritableOutput>
      inline constexpr bool has_output_reserve_v<
        WritableOutput,
        std::void_t<decltype( writable_output_trait<WritableOutput>::reserve(
          std::declval<WritableOutput &>( ), std::size_t{ } ) )>> = true;
    } // namespace concepts
 
    template<typename WritableOutput>
    constexpr WritableOutput &reserve_output( WritableOutput &out,
                                              std::size_t n ) {
      if constexpr( concepts::has_output_reserve_v<WritableOutput> ) {
        concepts::writable_output_trait<WritableOutput>::reserve( out, n );
      }
      return out;
    }
  } // namespace DAW_JSON_VER
} // namespace daw::json