path: root/src/boost/libs/outcome/test/tests/swap.cpp

/* Unit testing for outcomes
(C) 2013-2022 Niall Douglas <http://www.nedproductions.biz/> (5 commits)


Boost Software License - Version 1.0 - August 17th, 2003

Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:

The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/

#include <boost/outcome.hpp>
#include <boost/test/unit_test.hpp>
#include <boost/test/unit_test_monitor.hpp>

/* Should be this:

78 move constructor count = 2
65 move assignment count = 3
78 move assignment count = 1
65 move constructor count = 2
78 move assignment count = 0
65 move assignment count = 1

78 move constructor count = 1
65 move assignment count = 2
78 move assignment count = 0
65 move assignment count = 1
78 move assignment count = 0

78 move constructor count = 2
65 move assignment count = 3
78 move assignment count = 1
65 move constructor count = 2
78 move assignment count = 0
65 move assignment count = 1

78 move constructor count = 1
65 move assignment count = 2
78 move assignment count = 0
65 move assignment count = 1
78 move assignment count = 0

78 move constructor count = 2
65 move assignment count = 3
78 move assignment count = 1
65 move constructor count = 2
78 move assignment count = 0
65 move assignment count = 1

78 move constructor count = 1
65 move assignment count = 2
78 move assignment count = 0
65 move assignment count = 1
78 move assignment count = 0

78 move constructor count = 2
65 move assignment count = 3
78 move assignment count = 1
65 move constructor count = 2
78 move assignment count = 0
65 move assignment count = 1

78 move constructor count = 1
65 move assignment count = 2
78 move assignment count = 0
65 move assignment count = 1
78 move assignment count = 0
*/

#ifndef BOOST_NO_EXCEPTIONS
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4297)  // function assumed not to throw an exception but does
#endif
#if defined(__GNUC__) && !defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wterminate"
#endif
template <bool mc, bool ma> struct Throwy
{
  int count{0}, inc{0}, id{0};
  Throwy() = default;
  Throwy(int c, int d, int i = 1) noexcept
      : count(c)
      , inc(i)
      , id(d)
  {
  }
  Throwy(const Throwy &) = delete;
  Throwy &operator=(const Throwy &) = delete;
  Throwy(Throwy &&o) noexcept(!mc)
      : count(o.count - o.inc)
      , inc(o.inc)
      , id(o.id)  // NOLINT
  {
    if(mc)
    {
      std::cout << "   " << id << " move constructor count = " << count << std::endl;
      if(!count)
      {
        std::cout << "      " << id << " move constructor throws!" << std::endl;
        throw std::bad_alloc();
      }
    }
    o.count = 0;
    o.inc = 0;
    o.id = 0;
  }
  Throwy &operator=(Throwy &&o) noexcept(!ma)
  {
    count = o.count - o.inc;
    if(ma)
    {
      std::cout << "   " << o.id << " move assignment count = " << count << std::endl;
      if(!count)
      {
        std::cout << "      " << o.id << " move assignment throws!" << std::endl;
        throw std::bad_alloc();
      }
    }
    inc = o.inc;
    id = o.id;
    o.count = 0;
    o.inc = 0;
    o.id = 0;
    return *this;
  }
  ~Throwy() = default;
};
#if defined(__GNUC__) && !defined(__clang__)
#pragma GCC diagnostic pop
#endif
#ifdef _MSC_VER
#pragma warning(pop)
#endif
enum class ErrorCode
{
  dummy
};
enum class ErrorCode2
{
  dummy
};
template <bool mc, bool ma> using resulty1 = BOOST_OUTCOME_V2_NAMESPACE::result<Throwy<mc, ma>, ErrorCode, BOOST_OUTCOME_V2_NAMESPACE::policy::all_narrow>;
template <bool mc, bool ma> using resulty2 = BOOST_OUTCOME_V2_NAMESPACE::result<ErrorCode, Throwy<mc, ma>, BOOST_OUTCOME_V2_NAMESPACE::policy::all_narrow>;
template <bool mc, bool ma> using outcomey1 = BOOST_OUTCOME_V2_NAMESPACE::outcome<ErrorCode, Throwy<mc, ma>, ErrorCode2, BOOST_OUTCOME_V2_NAMESPACE::policy::all_narrow>;
template <bool mc, bool ma> using outcomey2 = BOOST_OUTCOME_V2_NAMESPACE::outcome<ErrorCode, ErrorCode2, Throwy<mc, ma>, BOOST_OUTCOME_V2_NAMESPACE::policy::all_narrow>;
#endif

BOOST_OUTCOME_AUTO_TEST_CASE(works_outcome_swap, "Tests that the outcome swaps as intended")
{
  using namespace BOOST_OUTCOME_V2_NAMESPACE;
  {  // Does swap actually swap?
    outcome<std::string> a("niall"), b("douglas");
    BOOST_CHECK(a.value() == "niall");
    BOOST_CHECK(b.value() == "douglas");
    swap(a, b);
    BOOST_CHECK(a.value() == "douglas");
    BOOST_CHECK(b.value() == "niall");
    a = boost::system::errc::not_enough_memory;
    swap(a, b);
    BOOST_CHECK(a.value() == "niall");
    BOOST_CHECK(b.error() == boost::system::errc::not_enough_memory);
    BOOST_CHECK(!a.has_lost_consistency());
    BOOST_CHECK(!b.has_lost_consistency());
  }
#ifndef BOOST_NO_EXCEPTIONS
  {  // Is noexcept propagated?
    using nothrow_t = Throwy<false, false>;
    using nothrow = resulty1<false, false>;
    static_assert(std::is_nothrow_move_constructible<nothrow_t>::value, "throwy not correct!");
    static_assert(std::is_nothrow_move_assignable<nothrow_t>::value, "throwy not correct!");
    static_assert(std::is_nothrow_move_constructible<nothrow>::value, "type not correct!");
    static_assert(std::is_nothrow_move_assignable<nothrow>::value, "type not correct!");

    static_assert(detail::is_nothrow_swappable<nothrow_t>::value, "is_nothrow_swappable is not correct!");

    static_assert(noexcept(nothrow(0, 0)), "type has a throwing value constructor!");
    nothrow a(1, 78), b(1, 65);
    a.swap(b);
    static_assert(noexcept(a.swap(b)), "type has a throwing swap!");
  }
  {  // Is noexcept propagated?
    using nothrow_t = Throwy<false, false>;
    using nothrow = resulty2<false, false>;
    static_assert(std::is_nothrow_move_constructible<nothrow_t>::value, "throwy not correct!");
    static_assert(std::is_nothrow_move_assignable<nothrow_t>::value, "throwy not correct!");
    static_assert(std::is_nothrow_move_constructible<nothrow>::value, "type not correct!");
    static_assert(std::is_nothrow_move_assignable<nothrow>::value, "type not correct!");

    static_assert(detail::is_nothrow_swappable<nothrow_t>::value, "is_nothrow_swappable is not correct!");

    static_assert(noexcept(nothrow(0, 0)), "type has a throwing value constructor!");
    nothrow a(1, 78), b(1, 65);
    a.swap(b);
    static_assert(noexcept(a.swap(b)), "type has a throwing swap!");
  }

  {  // Does swap implement the strong guarantee?
    using throwy_t = Throwy<true, true>;
    using throwy = resulty1<true, true>;
    static_assert(!std::is_nothrow_move_constructible<throwy_t>::value, "throwy not correct!");
    static_assert(!std::is_nothrow_move_assignable<throwy_t>::value, "throwy not correct!");
    static_assert(!std::is_nothrow_move_constructible<throwy>::value, "type not correct!");
    static_assert(!std::is_nothrow_move_assignable<throwy>::value, "type not correct!");

    static_assert(!detail::is_nothrow_swappable<throwy_t>::value, "is_nothrow_swappable is not correct!");

    std::cout << "Result value first swap succeeds, second swap second move assignment throws:" << std::endl;
    {
      throwy a(3, 78), b(4, 65);
      a.swap(b);
      static_assert(!noexcept(a.swap(b)), "type has a non-throwing swap!");
      BOOST_CHECK(a.value().id == 65);
      BOOST_CHECK(b.value().id == 78);
      try
      {
        a.swap(b);  // fails on first assignment
        BOOST_REQUIRE(false);
      }
      catch(const std::bad_alloc & /*unused*/)
      {
        BOOST_CHECK(a.value().id == 65);  // ensure it is perfectly restored
        BOOST_CHECK(b.value().id == 78);
      }
      BOOST_CHECK(!a.has_lost_consistency());
      BOOST_CHECK(!b.has_lost_consistency());
    }
    std::cout << "\nResult value second move assignment throws, on recover second move assignment throws:" << std::endl;
    {
      throwy a(2, 78), b(3, 65);  // fails on second assignment, cannot restore
      try
      {
        a.swap(b);
        BOOST_REQUIRE(false);
      }
      catch(const std::bad_alloc & /*unused*/)
      {
        BOOST_CHECK(a.has_lost_consistency());  // both must be marked tainted
        BOOST_CHECK(b.has_lost_consistency());
      }
    }
  }
  std::cout << "\nResult error first swap succeeds, second swap first move assignment throws:" << std::endl;
  {  // Does swap implement the strong guarantee?
    using throwy_t = Throwy<true, true>;
    using throwy = resulty2<true, true>;
    static_assert(!std::is_nothrow_move_constructible<throwy_t>::value, "throwy not correct!");
    static_assert(!std::is_nothrow_move_assignable<throwy_t>::value, "throwy not correct!");
    static_assert(!std::is_nothrow_move_constructible<throwy>::value, "type not correct!");
    static_assert(!std::is_nothrow_move_assignable<throwy>::value, "type not correct!");

    static_assert(!detail::is_nothrow_swappable<throwy_t>::value, "is_nothrow_swappable is not correct!");

    {
      throwy a(3, 78), b(4, 65);
      a.swap(b);
      static_assert(!noexcept(a.swap(b)), "type has a non-throwing swap!");
      BOOST_CHECK(a.error().id == 65);
      BOOST_CHECK(b.error().id == 78);
      try
      {
        a.swap(b);  // fails on first assignment
        BOOST_REQUIRE(false);
      }
      catch(const std::bad_alloc & /*unused*/)
      {
        BOOST_CHECK(a.error().id == 65);  // ensure it is perfectly restored
        BOOST_CHECK(b.error().id == 78);
      }
      BOOST_CHECK(!a.has_lost_consistency());
      BOOST_CHECK(!b.has_lost_consistency());
    }
    std::cout << "\nResult error second move assignment throws, on recover second move assignment throws:" << std::endl;
    {
      throwy a(2, 78), b(3, 65);  // fails on second assignment, cannot restore
      try
      {
        a.swap(b);
        BOOST_REQUIRE(false);
      }
      catch(const std::bad_alloc & /*unused*/)
      {
        BOOST_CHECK(a.has_lost_consistency());  // both must be marked tainted
        BOOST_CHECK(b.has_lost_consistency());
      }
    }
  }

  {  // Is noexcept propagated?
    using nothrow_t = Throwy<false, false>;
    using nothrow = outcomey1<false, false>;
    static_assert(std::is_nothrow_move_constructible<nothrow_t>::value, "throwy not correct!");
    static_assert(std::is_nothrow_move_assignable<nothrow_t>::value, "throwy not correct!");
    static_assert(std::is_nothrow_move_constructible<nothrow>::value, "type not correct!");
    static_assert(std::is_nothrow_move_assignable<nothrow>::value, "type not correct!");

    static_assert(detail::is_nothrow_swappable<nothrow_t>::value, "is_nothrow_swappable is not correct!");

    static_assert(noexcept(nothrow(0, 0)), "type has a throwing value constructor!");
    nothrow a(1, 78), b(1, 65);
    a.swap(b);
    static_assert(noexcept(a.swap(b)), "type has a throwing swap!");
  }
  {  // Is noexcept propagated?
    using nothrow_t = Throwy<false, false>;
    using nothrow = outcomey1<false, false>;
    static_assert(std::is_nothrow_move_constructible<nothrow_t>::value, "throwy not correct!");
    static_assert(std::is_nothrow_move_assignable<nothrow_t>::value, "throwy not correct!");
    static_assert(std::is_nothrow_move_constructible<nothrow>::value, "type not correct!");
    static_assert(std::is_nothrow_move_assignable<nothrow>::value, "type not correct!");

    static_assert(detail::is_nothrow_swappable<nothrow_t>::value, "is_nothrow_swappable is not correct!");

    static_assert(noexcept(nothrow(0, 0)), "type has a throwing value constructor!");
    nothrow a(1, 78), b(1, 65);
    a.swap(b);
    static_assert(noexcept(a.swap(b)), "type has a throwing swap!");
  }

  std::cout << "\n\nOutcome value first swap succeeds, second swap first move assignment throws:" << std::endl;
  {  // Does swap implement the strong guarantee?
    using throwy_t = Throwy<true, true>;
    using throwy = outcomey1<true, true>;
    static_assert(!std::is_nothrow_move_constructible<throwy_t>::value, "throwy not correct!");
    static_assert(!std::is_nothrow_move_assignable<throwy_t>::value, "throwy not correct!");
    static_assert(!std::is_nothrow_move_constructible<throwy>::value, "type not correct!");
    static_assert(!std::is_nothrow_move_assignable<throwy>::value, "type not correct!");

    static_assert(!detail::is_nothrow_swappable<throwy_t>::value, "is_nothrow_swappable is not correct!");

    {
      throwy a(3, 78), b(4, 65);
      a.swap(b);
      static_assert(!noexcept(a.swap(b)), "type has a non-throwing swap!");
      BOOST_CHECK(a.error().id == 65);
      BOOST_CHECK(b.error().id == 78);
      try
      {
        a.swap(b);  // fails on first assignment
        BOOST_REQUIRE(false);
      }
      catch(const std::bad_alloc & /*unused*/)
      {
        BOOST_CHECK(a.error().id == 65);  // ensure it is perfectly restored
        BOOST_CHECK(b.error().id == 78);
      }
      BOOST_CHECK(!a.has_lost_consistency());
      BOOST_CHECK(!b.has_lost_consistency());
    }
    std::cout << "\nOutcome value second move assignment throws, on recover second move assignment throws:" << std::endl;
    {
      throwy a(2, 78), b(3, 65);  // fails on second assignment, cannot restore
      try
      {
        a.swap(b);
        BOOST_REQUIRE(false);
      }
      catch(const std::bad_alloc & /*unused*/)
      {
        BOOST_CHECK(a.has_lost_consistency());  // both must be marked tainted
        BOOST_CHECK(b.has_lost_consistency());
      }
    }
  }
  std::cout << "\nOutcome error first swap succeeds, second swap first move assignment throws:" << std::endl;
  {  // Does swap implement the strong guarantee?
    using throwy_t = Throwy<true, true>;
    using throwy = outcomey2<true, true>;
    static_assert(!std::is_nothrow_move_constructible<throwy_t>::value, "throwy not correct!");
    static_assert(!std::is_nothrow_move_assignable<throwy_t>::value, "throwy not correct!");
    static_assert(!std::is_nothrow_move_constructible<throwy>::value, "type not correct!");
    static_assert(!std::is_nothrow_move_assignable<throwy>::value, "type not correct!");

    static_assert(!detail::is_nothrow_swappable<throwy_t>::value, "is_nothrow_swappable is not correct!");

    {
      throwy a(3, 78), b(4, 65);
      a.swap(b);
      static_assert(!noexcept(a.swap(b)), "type has a non-throwing swap!");
      BOOST_CHECK(a.exception().id == 65);
      BOOST_CHECK(b.exception().id == 78);
      try
      {
        a.swap(b);  // fails on first assignment
        BOOST_REQUIRE(false);
      }
      catch(const std::bad_alloc & /*unused*/)
      {
        BOOST_CHECK(a.exception().id == 65);  // ensure it is perfectly restored
        BOOST_CHECK(b.exception().id == 78);
      }
      BOOST_CHECK(!a.has_lost_consistency());
      BOOST_CHECK(!b.has_lost_consistency());
    }
    std::cout << "\nOutcome error second move assignment throws, on recover second move assignment throws:" << std::endl;
    {
      throwy a(2, 78), b(3, 65);  // fails on second assignment, cannot restore
      try
      {
        a.swap(b);
        BOOST_REQUIRE(false);
      }
      catch(const std::bad_alloc & /*unused*/)
      {
        BOOST_CHECK(a.has_lost_consistency());  // both must be marked tainted
        BOOST_CHECK(b.has_lost_consistency());
      }
    }
    std::cout << std::endl;
  }
#endif
}