optional/test/optional_test_ref_to_val.cpp

// Copyright (C) 2016 Andrzej Krzemienski.
//
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/lib/optional for documentation.
//
// You are welcome to contact the author at:
//  akrzemi1@gmail.com


#include "boost/optional/optional.hpp"

#ifdef BOOST_BORLANDC
#pragma hdrstop
#endif

#include "boost/core/lightweight_test.hpp"

using boost::optional;
using boost::none;

struct Value
{
  int val;
  explicit Value(int v) : val(v) {}
};

int val(int const& i)
{
  return i;
}

int val(Value const& v)
{
  return v.val;
}

template <typename Tref>
optional<Tref&> make_opt_ref(Tref& v)
{
  return optional<Tref&>(v);
}

template <typename Tval, typename Tref>
void test_construct_from_optional_ref()
{
    Tref v1 (1), v2 (2);
    
    optional<Tref&> opt_ref0;
    optional<Tref&> opt_ref1 (v1);
    
    optional<Tval> opt_val0 (opt_ref0);
    optional<Tval> opt_val1 (opt_ref1);
    optional<Tval> opt_val2 (make_opt_ref(v2));
    
    BOOST_TEST (!opt_val0);
    BOOST_TEST (opt_val1);
    BOOST_TEST (opt_val2);
    
    BOOST_TEST_EQ (1, val(*opt_val1));
    BOOST_TEST_EQ (2, val(*opt_val2));
    
    BOOST_TEST (boost::addressof(*opt_val1) != boost::addressof(v1));
    BOOST_TEST (boost::addressof(*opt_val2) != boost::addressof(v2));
}

template <typename Tval, typename Tref>
void test_assign_from_optional_ref()
{
    Tref v1 (1), v2 (2);
    
    optional<Tref&> opt_ref0;
    optional<Tref&> opt_ref1 (v1);
    
    optional<Tval> opt_val0;
    optional<Tval> opt_val1;
    optional<Tval> opt_val2;
    
    opt_val0 = opt_ref0;
    opt_val1 = opt_ref1;
    opt_val2 = make_opt_ref(v2);
    
    BOOST_TEST (!opt_val0);
    BOOST_TEST (opt_val1);
    BOOST_TEST (opt_val2);
    
    BOOST_TEST_EQ (1, val(*opt_val1));
    BOOST_TEST_EQ (2, val(*opt_val2));
    
    BOOST_TEST (boost::addressof(*opt_val1) != boost::addressof(v1));
    BOOST_TEST (boost::addressof(*opt_val2) != boost::addressof(v2));
}


int main()
{
    test_construct_from_optional_ref<int, int>();
    test_construct_from_optional_ref<int, int const>();
    test_construct_from_optional_ref<int const, int const>();
    test_construct_from_optional_ref<int const, int>();
    
    test_construct_from_optional_ref<Value, Value>();
    test_construct_from_optional_ref<Value, Value const>();
    test_construct_from_optional_ref<Value const, Value const>();
    test_construct_from_optional_ref<Value const, Value>();
    
    test_assign_from_optional_ref<int, int>();
    test_assign_from_optional_ref<int, int const>();

    test_assign_from_optional_ref<Value, Value>();
    test_assign_from_optional_ref<Value, Value const>();

    return boost::report_errors();
}