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

   1 /*=============================================================================
   2     Copyright (c) 2017 Paul Fultz II
   3     repeat_while.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/repeat_while.hpp>
   8 #include <boost/hof/reveal.hpp>
   9 #include "test.hpp"
  10
  11 // TODO: Test default construction, and static initialization
  12
  13 struct increment_constant
  14 {
  15     template<class T>
  16     constexpr std::integral_constant<int, T::value + 1> operator()(T) const noexcept
  17     {
  18         return std::integral_constant<int, T::value + 1>();
  19     }
  20 };
  21
  22 struct increment
  23 {
  24     template<class T>
  25     constexpr T operator()(T x) const noexcept
  26     {
  27         return x + 1;
  28     }
  29 };
  30
  31 struct not_6_constant
  32 {
  33     template<class T>
  34     constexpr std::integral_constant<bool, (T::value != 6)>
  35     operator()(T) const noexcept
  36     {
  37         return std::integral_constant<bool, (T::value != 6)>();
  38     }
  39 };
  40
  41 struct not_6
  42 {
  43     template<class T>
  44     constexpr bool operator()(T x) const noexcept
  45     {
  46         return x != 6;
  47     }
  48 };
  49
  50 struct not_limit
  51 {
  52     template<class T>
  53     constexpr bool operator()(T x) const
  54     {
  55         return x != (BOOST_HOF_RECURSIVE_CONSTEXPR_DEPTH+4);
  56     }
  57 };
  58
  59 #if BOOST_HOF_HAS_NOEXCEPT_DEDUCTION
  60 BOOST_HOF_TEST_CASE()
  61 {
  62     static_assert(noexcept(boost::hof::repeat_while(not_6())(increment())(1)), "noexcept repeat_while");
  63     static_assert(noexcept(boost::hof::repeat_while(not_6_constant())(increment_constant())(std::integral_constant<int, 1>())), "noexcept repeat_while");
  64 }
  65 #endif
  66
  67 BOOST_HOF_TEST_CASE()
  68 {
  69     static_assert
  70     (
  71         std::is_same<
  72             std::integral_constant<int, 6>,
  73             decltype(boost::hof::repeat_while(not_6_constant())(increment_constant())(std::integral_constant<int, 1>()))
  74         >::value,
  75         "Error"
  76     );
  77
  78     std::integral_constant<int, 6> x = boost::hof::repeat_while(not_6_constant())(increment_constant())(std::integral_constant<int, 1>());
  79     boost::hof::test::unused(x);
  80 }
  81
  82 BOOST_HOF_TEST_CASE()
  83 {
  84     BOOST_HOF_STATIC_TEST_CHECK(boost::hof::repeat_while(not_6())(increment())(1) == 6);
  85     BOOST_HOF_TEST_CHECK(boost::hof::repeat_while(not_6())(increment())(1) == 6);
  86     BOOST_HOF_TEST_CHECK(boost::hof::reveal(boost::hof::repeat_while(not_6())(increment()))(1) == 6);
  87 }
  88
  89 BOOST_HOF_TEST_CASE()
  90 {
  91     BOOST_HOF_TEST_CHECK(boost::hof::repeat_while(not_limit())(increment())(1) == BOOST_HOF_RECURSIVE_CONSTEXPR_DEPTH+4);
  92 #if BOOST_HOF_HAS_RELAXED_CONSTEXPR
  93     BOOST_HOF_STATIC_TEST_CHECK(boost::hof::repeat_while(not_limit())(increment())(1) == BOOST_HOF_RECURSIVE_CONSTEXPR_DEPTH+4);
  94 #endif
  95 }