ceph/src/boost/libs/hof/test/implicit.cpp

   1 /*=============================================================================
   2     Copyright (c) 2017 Paul Fultz II
   3     implicit.cpp
   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 #include <boost/hof/implicit.hpp>
   8 #include "test.hpp"
   9
  10 template<class T>
  11 struct auto_caster
  12 {
  13     template<class U>
  14     T operator()(U x)
  15     {
  16         return T(x);
  17     }
  18 };
  19
  20 template<class T>
  21 struct auto_caster_noexcept
  22 {
  23     template<class U>
  24     T operator()(U x) noexcept
  25     {
  26         return T(x);
  27     }
  28 };
  29
  30 struct auto_caster_foo
  31 {
  32     int i;
  33     explicit auto_caster_foo(int ip) : i(ip) {}
  34
  35 };
  36 // TODO: Test template constraint on conversion operator
  37 static constexpr boost::hof::implicit<auto_caster> auto_cast = {};
  38
  39 BOOST_HOF_TEST_CASE()
  40 {
  41     float f = 1.5;
  42     int i = auto_cast(f);
  43     // auto_caster_foo x = 1;
  44     auto_caster_foo x = auto_cast(1);
  45     BOOST_HOF_TEST_CHECK(1 == i);
  46     BOOST_HOF_TEST_CHECK(1 == x.i);
  47
  48 }
  49 #if BOOST_HOF_HAS_NOEXCEPT_DEDUCTION
  50 BOOST_HOF_TEST_CASE()
  51 {
  52     boost::hof::implicit<auto_caster_noexcept> lauto_cast{};
  53     float f = 1.5;
  54     static_assert(noexcept(int(lauto_cast(f))), "noexcept implicit");
  55 }
  56 #endif