#include <gtest/gtest.h>
#include <m5_utility/stl/expected.hpp>

struct move_detector {
    move_detector() = default;
    move_detector(move_detector &&rhs)
    {
        rhs.been_moved = true;
    }
    bool been_moved = false;
};

TEST(Expected, Observers)
{
    m5::stl::expected<int, int> o1 = 42;
    m5::stl::expected<int, int> o2{m5::stl::unexpect, 0};
    const m5::stl::expected<int, int> o3 = 42;

    EXPECT_TRUE(*o1 == 42);
    EXPECT_TRUE(*o1 == o1.value());
    EXPECT_TRUE(o2.value_or(42) == 42);
    EXPECT_TRUE(o2.error() == 0);
    EXPECT_TRUE(o3.value() == 42);
    auto success = std::is_same<decltype(o1.value()), int &>::value;
    EXPECT_TRUE(success);
    success = std::is_same<decltype(o3.value()), const int &>::value;
    EXPECT_TRUE(success);
    success = std::is_same<decltype(std::move(o1).value()), int &&>::value;
    EXPECT_TRUE(success);

#ifndef TL_EXPECTED_NO_CONSTRR
    success = std::is_same<decltype(std::move(o3).value()), const int &&>::value;
    EXPECT_TRUE(success);
#endif

    m5::stl::expected<move_detector, int> o4{m5::stl::in_place};
    move_detector o5 = std::move(o4).value();
    EXPECT_TRUE(o4->been_moved);
    EXPECT_TRUE(!o5.been_moved);

    // Add by GOB
    EXPECT_TRUE(o1.error_or(52) == 52);
    EXPECT_TRUE(o2.error_or(52) == 0);
}