ceph/src/boost/libs/hana/example/tutorial/introspection.adapt.cpp

   1 // Copyright Louis Dionne 2013-2017
   2 // Distributed under the Boost Software License, Version 1.0.
   3 // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   4
   5 #include <boost/hana.hpp>
   6
   7 #include <iostream>
   8 #include <string>
   9 namespace hana = boost::hana;
  10 using namespace hana::literals;
  11 using namespace std::literals;
  12
  13
  14 //! [BOOST_HANA_DEFINE_STRUCT]
  15 struct Person {
  16   BOOST_HANA_DEFINE_STRUCT(Person,
  17     (std::string, name),
  18     (int, age)
  19   );
  20 };
  21 //! [BOOST_HANA_DEFINE_STRUCT]
  22
  23 int main() {
  24
  25 //! [for_each]
  26 Person john{"John", 30};
  27
  28 hana::for_each(john, [](auto pair) {
  29   std::cout << hana::to<char const*>(hana::first(pair)) << ": "
  30             << hana::second(pair) << std::endl;
  31 });
  32
  33 // name: John
  34 // age: 30
  35 //! [for_each]
  36
  37 //! [for_each.fuse]
  38 hana::for_each(john, hana::fuse([](auto name, auto member) {
  39   std::cout << hana::to<char const*>(name) << ": " << member << std::endl;
  40 }));
  41 //! [for_each.fuse]
  42
  43 #ifdef BOOST_HANA_CONFIG_ENABLE_STRING_UDL
  44
  45 {
  46
  47 //! [at_key]
  48 std::string name = hana::at_key(john, "name"_s);
  49 BOOST_HANA_RUNTIME_CHECK(name == "John");
  50
  51 int age = hana::at_key(john, "age"_s);
  52 BOOST_HANA_RUNTIME_CHECK(age == 30);
  53 //! [at_key]
  54
  55 }{
  56
  57 //! [to<map_tag>]
  58 auto map = hana::insert(hana::to<hana::map_tag>(john), hana::make_pair("last name"_s, "Doe"s));
  59
  60 std::string name = map["name"_s];
  61 BOOST_HANA_RUNTIME_CHECK(name == "John");
  62
  63 std::string last_name = map["last name"_s];
  64 BOOST_HANA_RUNTIME_CHECK(last_name == "Doe");
  65
  66 int age = map["age"_s];
  67 BOOST_HANA_RUNTIME_CHECK(age == 30);
  68 //! [to<map_tag>]
  69
  70 }
  71
  72 #endif
  73
  74 }
  75
  76 //! [BOOST_HANA_ADAPT_STRUCT]
  77 namespace not_my_namespace {
  78   struct Person {
  79     std::string name;
  80     int age;
  81   };
  82 }
  83
  84 BOOST_HANA_ADAPT_STRUCT(not_my_namespace::Person, name, age);
  85 //! [BOOST_HANA_ADAPT_STRUCT]
  86
  87
  88 //! [BOOST_HANA_ADAPT_ADT]
  89 namespace also_not_my_namespace {
  90   struct Person {
  91     std::string get_name();
  92     int get_age();
  93   };
  94 }
  95
  96 BOOST_HANA_ADAPT_ADT(also_not_my_namespace::Person,
  97   (name, [](auto const& p) { return p.get_name(); }),
  98   (age, [](auto const& p) { return p.get_age(); })
  99 );
 100 //! [BOOST_HANA_ADAPT_ADT]