ceph/src/boost/libs/hana/test/concept/struct/at_key.cpp

   1 // Copyright Louis Dionne 2013-2016
   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/assert.hpp>
   6 #include <boost/hana/at_key.hpp>
   7 #include <boost/hana/define_struct.hpp>
   8 #include <boost/hana/string.hpp>
   9
  10 #include <string>
  11 namespace hana = boost::hana;
  12
  13
  14 struct Person {
  15     BOOST_HANA_DEFINE_STRUCT(Person,
  16         (std::string, name),
  17         (std::string, last_name),
  18         (int, age)
  19     );
  20 };
  21
  22 int main() {
  23     // non-const ref
  24     {
  25         Person john{"John", "Doe", 30};
  26         std::string& name = hana::at_key(john, BOOST_HANA_STRING("name"));
  27         std::string& last_name = hana::at_key(john, BOOST_HANA_STRING("last_name"));
  28         int& age = hana::at_key(john, BOOST_HANA_STRING("age"));
  29
  30         name = "Bob";
  31         last_name = "Foo";
  32         age = 99;
  33
  34         BOOST_HANA_RUNTIME_CHECK(john.name == "Bob");
  35         BOOST_HANA_RUNTIME_CHECK(john.last_name == "Foo");
  36         BOOST_HANA_RUNTIME_CHECK(john.age == 99);
  37     }
  38
  39     // const ref
  40     {
  41         Person john{"John", "Doe", 30};
  42         Person const& const_john = john;
  43         std::string const& name = hana::at_key(const_john, BOOST_HANA_STRING("name"));
  44         std::string const& last_name = hana::at_key(const_john, BOOST_HANA_STRING("last_name"));
  45         int const& age = hana::at_key(const_john, BOOST_HANA_STRING("age"));
  46
  47         john.name = "Bob";
  48         john.last_name = "Foo";
  49         john.age = 99;
  50
  51         BOOST_HANA_RUNTIME_CHECK(name == "Bob");
  52         BOOST_HANA_RUNTIME_CHECK(last_name == "Foo");
  53         BOOST_HANA_RUNTIME_CHECK(age == 99);
  54     }
  55 }