ceph/src/boost/libs/hana/test/detail/ebo.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/detail/ebo.hpp>
   6
   7 #include <boost/hana/assert.hpp>
   8
   9 #include <string>
  10 #include <type_traits>
  11 #include <utility>
  12 namespace hana = boost::hana;
  13 using hana::detail::ebo;
  14
  15
  16 template <int> struct empty { };
  17 template <int> struct idx;
  18 template <typename ...Bases> struct inherit : Bases... { };
  19
  20 static_assert(sizeof(inherit<>) == sizeof(inherit<ebo<idx<0>, empty<0>>>), "");
  21 static_assert(sizeof(inherit<>) == sizeof(inherit<ebo<idx<0>, empty<0>>, ebo<idx<1>, empty<1>>>), "");
  22 static_assert(sizeof(inherit<>) == sizeof(inherit<ebo<idx<0>, empty<0>>, ebo<idx<1>, empty<1>>, ebo<idx<2>, empty<2>>>), "");
  23
  24
  25 int main() {
  26     // Test default-construction
  27     {
  28         constexpr ebo<idx<0>, int> e;
  29         static_assert(hana::detail::ebo_get<idx<0>>(e) == 0, "");
  30     }
  31
  32     // Test construction of a non-empty object
  33     {
  34         ebo<idx<0>, std::string> e{"foobar"};
  35         BOOST_HANA_RUNTIME_CHECK(hana::detail::ebo_get<idx<0>>(e) == "foobar");
  36     }
  37
  38     {
  39         ebo<idx<0>, std::string> e{};
  40         BOOST_HANA_RUNTIME_CHECK(hana::detail::ebo_get<idx<0>>(e) == "");
  41     }
  42
  43     // Test construction of a non default-constructible type
  44     {
  45         struct nodefault {
  46             nodefault() = delete;
  47             explicit nodefault(char const*) { }
  48         };
  49         ebo<idx<0>, nodefault> e{"foobar"};
  50     }
  51
  52     // Get lvalue, const lvalue and rvalue with a non-empty type
  53     {
  54         ebo<idx<0>, std::string> e{"foobar"};
  55         std::string& s = hana::detail::ebo_get<idx<0>>(e);
  56         BOOST_HANA_RUNTIME_CHECK(s == "foobar");
  57         s = "foobaz";
  58         BOOST_HANA_RUNTIME_CHECK(hana::detail::ebo_get<idx<0>>(e) == "foobaz");
  59     }
  60
  61     {
  62         ebo<idx<0>, std::string> const e{"foobar"};
  63         std::string const& s = hana::detail::ebo_get<idx<0>>(e);
  64         BOOST_HANA_RUNTIME_CHECK(s == "foobar");
  65     }
  66
  67     {
  68         ebo<idx<0>, std::string> e{"foobar"};
  69         std::string&& s = hana::detail::ebo_get<idx<0>>(std::move(e));
  70         BOOST_HANA_RUNTIME_CHECK(s == "foobar");
  71     }
  72
  73     // Get lvalue, const lvalue and rvalue with an empty type
  74     {
  75         ebo<idx<0>, empty<0>> e{};
  76         empty<0>& s = hana::detail::ebo_get<idx<0>>(e);
  77         (void)s;
  78     }
  79
  80     {
  81         ebo<idx<0>, empty<0>> const e{};
  82         empty<0> const& s = hana::detail::ebo_get<idx<0>>(e);
  83         (void)s;
  84     }
  85
  86     {
  87         ebo<idx<0>, empty<0>> e{};
  88         empty<0>&& s = hana::detail::ebo_get<idx<0>>(std::move(e));
  89         (void)s;
  90     }
  91 }