outcome/test/tests/experimental-core-outcome-status.cpp

/* Unit testing for outcomes
(C) 2013-2019 Niall Douglas <http://www.nedproductions.biz/> (4 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
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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
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
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*/

#include <boost/outcome/experimental/status_outcome.hpp>

#define BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND std
template <class T, class S = BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE::system_code, class P = BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::exception_ptr> using outcome = BOOST_OUTCOME_V2_NAMESPACE::experimental::status_outcome<T, S, P>;
using BOOST_OUTCOME_V2_NAMESPACE::in_place_type;

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

#include <iostream>

#ifdef _MSC_VER
#pragma warning(disable : 4702)  // unreachable code
#endif

BOOST_OUTCOME_AUTO_TEST_CASE(works_status_code_outcome, "Tests that the outcome with status_code works as intended")
{
  using namespace BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE;

  {  // errored int
    outcome<int> m(generic_code{errc::bad_address});
    BOOST_CHECK(!m);
    BOOST_CHECK(!m.has_value());
    BOOST_CHECK(m.has_error());
    BOOST_CHECK(!m.has_exception());
    BOOST_CHECK_THROW(m.value(), status_error<void>);
    BOOST_CHECK_NO_THROW(m.error());
    BOOST_CHECK_THROW(BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::rethrow_exception(m.failure()), generic_error);
  }
  {  // errored void
    outcome<void> m(generic_code{errc::bad_address});
    BOOST_CHECK(!m);
    BOOST_CHECK(!m.has_value());
    BOOST_CHECK(m.has_error());
    BOOST_CHECK(!m.has_exception());
    BOOST_CHECK_THROW(([&m]() -> void { return m.value(); }()), generic_error);
    BOOST_CHECK_NO_THROW(m.error());
    BOOST_CHECK_THROW(BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::rethrow_exception(m.failure()), generic_error);
  }
  {  // valued int
    outcome<int> m(5);
    BOOST_CHECK(m);
    BOOST_CHECK(m.has_value());
    BOOST_CHECK(!m.has_error());
    BOOST_CHECK(!m.has_exception());
    BOOST_CHECK(m.value() == 5);
    m.value() = 6;
    BOOST_CHECK(m.value() == 6);
    BOOST_CHECK(!m.failure());
  }
  {  // moves do not clear state
    outcome<std::string> m("niall");
    BOOST_CHECK(m);
    BOOST_CHECK(m.has_value());
    BOOST_CHECK(!m.has_error());
    BOOST_CHECK(!m.has_exception());
    BOOST_CHECK(m.value() == "niall");
    m.value() = "NIALL";
    BOOST_CHECK(m.value() == "NIALL");
    auto temp(std::move(m).value());
    BOOST_CHECK(temp == "NIALL");
    BOOST_CHECK(m.value().empty());  // NOLINT
  }
  {  // valued void
    outcome<void> m(in_place_type<void>);
    BOOST_CHECK(m);
    BOOST_CHECK(m.has_value());
    BOOST_CHECK(!m.has_error());
    BOOST_CHECK(!m.has_exception());
    BOOST_CHECK_NO_THROW(m.value());  // works, but type returned is unusable
    BOOST_CHECK(!m.failure());
  }
  {  // errored
    error ec(errc::no_link);
    outcome<int> m(ec.clone());
    BOOST_CHECK(!m);
    BOOST_CHECK(!m.has_value());
    BOOST_CHECK(m.has_error());
    BOOST_CHECK(!m.has_exception());
    BOOST_CHECK_THROW(m.value(), generic_error);
    BOOST_CHECK(m.error() == ec);
#ifndef BOOST_NO_EXCEPTIONS
    BOOST_CHECK(m.failure());
    try
    {
      BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::rethrow_exception(m.failure());
    }
    catch(const generic_error &ex)
    {
      BOOST_CHECK(ex.code() == ec);
      BOOST_CHECK(ex.code().value() == errc::no_link);
    }
#endif
  }
#if !defined(__APPLE__) || defined(__cpp_exceptions)
  {  // excepted
    BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::error_code ec(5, BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::system_category());
    auto e = BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::make_exception_ptr(BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::system_error(ec));  // NOLINT
    outcome<int> m(e);
    BOOST_CHECK(!m);
    BOOST_CHECK(!m.has_value());
    BOOST_CHECK(!m.has_error());
    BOOST_CHECK(m.has_exception());
    BOOST_CHECK_THROW(m.value(), BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::system_error);
    BOOST_CHECK(m.exception() == e);
#ifndef BOOST_NO_EXCEPTIONS
    BOOST_CHECK(m.failure());
    try
    {
      BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::rethrow_exception(m.failure());
    }
    catch(const BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::system_error &ex)
    {
      BOOST_CHECK(ex.code() == ec);
      BOOST_CHECK(ex.code().value() == 5);
    }
#endif
  }
  {  // custom error type
    struct Foo
    {
    };
    auto e = BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::make_exception_ptr(Foo());
    outcome<int> m(e);
    BOOST_CHECK(!m);
    BOOST_CHECK(!m.has_value());
    BOOST_CHECK(!m.has_error());
    BOOST_CHECK(m.has_exception());
    BOOST_CHECK_THROW(m.value(), Foo);
    BOOST_CHECK(m.exception() == e);
  }
  {  // outcome<void, void> should work
    BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::error_code ec(5, BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::system_category());
    auto e = BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::make_exception_ptr(BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::system_error(ec));
    outcome<void, void> m(e);
    BOOST_CHECK(!m);
    BOOST_CHECK(!m.has_value());
    BOOST_CHECK(!m.has_error());
    BOOST_CHECK(m.has_exception());
  }
#endif


  {
    outcome<int> a(5);
    outcome<int> b(generic_code{errc::invalid_argument});
    std::cout << sizeof(a) << std::endl;  // 40 bytes
    a.assume_value();
    b.assume_error();
#ifndef BOOST_NO_EXCEPTIONS
    try
    {
      b.value();
      std::cerr << "fail" << std::endl;
      std::terminate();
    }
    catch(const generic_error & /*unused*/)
    {
    }
#endif
    static_assert(!std::is_default_constructible<decltype(a)>::value, "");
    static_assert(!std::is_nothrow_default_constructible<decltype(a)>::value, "");
    static_assert(!std::is_copy_constructible<decltype(a)>::value, "");
    static_assert(!std::is_trivially_copy_constructible<decltype(a)>::value, "");
    static_assert(!std::is_nothrow_copy_constructible<decltype(a)>::value, "");
    static_assert(!std::is_copy_assignable<decltype(a)>::value, "");
    static_assert(!std::is_trivially_copy_assignable<decltype(a)>::value, "");
    static_assert(!std::is_nothrow_copy_assignable<decltype(a)>::value, "");
    static_assert(!std::is_trivially_destructible<decltype(a)>::value, "");
    static_assert(std::is_nothrow_destructible<decltype(a)>::value, "");

    // Test void compiles
    outcome<void> c(in_place_type<void>);
    // Test int, void compiles
    outcome<int, void> d(in_place_type<BOOST_OUTCOME_PREVENT_CONVERSION_WORKAROUND::exception_ptr>);
  }

  {
    // Can only be constructed via multiple args
    struct udt3
    {
      udt3() = delete;
      udt3(udt3 &&) = delete;
      udt3(const udt3 &) = delete;
      udt3 &operator=(udt3 &&) = delete;
      udt3 &operator=(const udt3 &) = delete;
      explicit udt3(int /*unused*/, const char * /*unused*/, std::nullptr_t /*unused*/) {}
      ~udt3() = default;
    };
    // Test a udt which can only be constructed in place compiles
    outcome<udt3> g(in_place_type<udt3>, 5, static_cast<const char *>("niall"), nullptr);
    // Does converting inplace construction also work?
    outcome<udt3> h(5, static_cast<const char *>("niall"), nullptr);
    BOOST_CHECK(h.has_value());
  }
}