ceph/src/boost/libs/json/test/doc_forward_conversion.cpp

   1 //
   2 // Copyright (c) 2021 Dmitry Arkhipov (grisumbras@gmail.com)
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // Official repository: https://github.com/boostorg/json
   8 //
   9
  10 //[doc_forward_conversion_1
  11 namespace boost {
  12 namespace json {
  13
  14 class value;
  15
  16 struct value_from_tag;
  17
  18 template< class T >
  19 struct value_to_tag;
  20
  21 template< class T >
  22 T value_to( const value& v );
  23
  24 template<class T>
  25 void value_from( T&& t, value& jv );
  26
  27 }
  28 }
  29 //]
  30
  31 #include <string>
  32
  33 namespace thirdparty {
  34
  35 struct customer
  36 {
  37     std::uint64_t id;
  38     std::string name;
  39     bool late;
  40
  41     customer() = default;
  42
  43     customer( std::uint64_t i, const std::string& n, bool l )
  44         : id( i ), name( n ), late( l ) { }
  45 };
  46
  47 } // namespace thirdparty
  48
  49 //[doc_forward_conversion_2
  50 namespace thirdparty {
  51
  52 template< class JsonValue >
  53 customer tag_invoke( const boost::json::value_to_tag<customer>&, const JsonValue& jv )
  54 {
  55     std::uint64_t id = boost::json::value_to<std::uint64_t>( jv.at( "id" ) );
  56     std::string name = boost::json::value_to< std::string >( jv.at( "name" ) );
  57     bool late = boost::json::value_to<bool>( jv.at( "late" ) );
  58     return customer(id, std::move(name), late);
  59 }
  60
  61 template< class JsonValue >
  62 void tag_invoke( const boost::json::value_from_tag&, JsonValue& jv, const customer& c)
  63 {
  64     auto& obj = jv.emplace_object();
  65     boost::json::value_from(c.id, obj["id"]);
  66     boost::json::value_from(c.name, obj["name"]);
  67     boost::json::value_from(c.late, obj["late"]);
  68 }
  69
  70 }
  71 //]
  72
  73
  74 #include <boost/json/value_from.hpp>
  75 #include <boost/json/value_to.hpp>
  76
  77 #include "test_suite.hpp"
  78
  79
  80 BOOST_JSON_NS_BEGIN
  81
  82 class doc_forward_conversion
  83 {
  84 public:
  85     void
  86     run()
  87     {
  88         value const jv{ { "id", 1 }, { "name", "Carl" }, { "late", true } };
  89         auto const c = value_to<thirdparty::customer>( jv );
  90         BOOST_TEST( c.id == 1 );
  91         BOOST_TEST( c.name == "Carl" );
  92         BOOST_TEST( c.late );
  93
  94         value const jv2 = value_from( c );
  95         BOOST_TEST( jv == jv2 );
  96     }
  97 };
  98
  99 TEST_SUITE(doc_forward_conversion, "boost.json.doc_forward_conversion");
 100
 101 BOOST_JSON_NS_END