// Copyright (C) 2020 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only

#define QT_USE_QSTRINGBUILDER
#define QFLATMAP_ENABLE_STL_COMPATIBLE_INSERT

#include <QTest>

#include <private/qflatmap_p.h>
#include <qbytearray.h>
#include <qstring.h>
#include <qstringview.h>
#include <qvarlengtharray.h>

#include <algorithm>
#include <list>
#include <tuple>

static constexpr bool is_even(int n) { return n % 2 == 0; }
static constexpr bool is_empty(QAnyStringView v) { return v.isEmpty(); }

namespace {
template <typename P>
constexpr inline bool is_pair_impl_v = false;
template <typename T, typename S>
constexpr inline bool is_pair_impl_v<std::pair<T,S>> = true;
template <typename P>
constexpr inline bool is_pair_v = is_pair_impl_v<std::decay_t<P>>;
template <typename P>
using if_pair = std::enable_if_t<is_pair_v<P>, bool>;
}

class tst_QFlatMap : public QObject
{
    Q_OBJECT
private slots:
    void constructing();
    void constAccess();
    void insertion();
    void insertRValuesAndLValues();
    void removal();
    void extraction();
    void iterators();
    void remove_if_pair() { remove_if_impl([](const auto &p) -> if_pair<decltype(p)> { return is_even(p.first) && is_empty(p.second); }); }
    void remove_if_key_value() { remove_if_impl([](const auto &k, const auto &v) { return is_even(k) && is_empty(v); }); }
    void remove_if_key() { remove_if_impl([](int k) { return is_even(k); }, true); }
    void statefulComparator();
    void transparency_using();
    void transparency_struct();
    void try_emplace_and_insert_or_assign();
    void viewIterators();
    void varLengthArray();

private:
    template <typename Compare>
    void transparency_impl();
    template <typename Predicate>
    void remove_if_impl(Predicate p, bool removeNonEmptyValues = false);
};

void tst_QFlatMap::constructing()
{
    using Map = QFlatMap<int, QByteArray>;
    Map fmDefault;
    QVERIFY(fmDefault.isEmpty());
    QCOMPARE(fmDefault.size(), Map::size_type(0));
    QCOMPARE(fmDefault.size(), fmDefault.count());

    auto key_compare = fmDefault.key_comp();
    auto selfbuilt_value_compare
            = [&key_compare](const Map::value_type &a, const Map::value_type &b)
              {
                  return key_compare(a.first, b.first);
              };
    auto value_compare = fmDefault.value_comp();

    Map::key_container_type kv = { 6, 2, 1 };
    Map::mapped_container_type mv = { "foo", "bar", "baz" };
    Map fmCopy{kv, mv};
    QCOMPARE(fmCopy.size(), Map::size_type(3));
    QVERIFY(std::is_sorted(fmCopy.begin(), fmCopy.end(), selfbuilt_value_compare));
    QVERIFY(std::is_sorted(fmCopy.begin(), fmCopy.end(), value_compare));

    Map fmMove{
        Map::key_container_type{ 6, 2, 1 },
        Map::mapped_container_type{ "foo", "bar", "baz" }
    };
    QCOMPARE(fmMove.size(), Map::size_type(3));
    QVERIFY(std::is_sorted(fmMove.begin(), fmMove.end(), value_compare));

    auto fmInitList = Map{ { 1, 2 }, { "foo", "bar" } };
    QVERIFY(std::is_sorted(fmInitList.begin(), fmInitList.end(), value_compare));

    auto fmRange = Map(fmCopy.begin(), fmCopy.end());
    QVERIFY(std::is_sorted(fmRange.begin(), fmRange.end(), value_compare));

    kv.clear();
    mv.clear();
    std::vector<Map::value_type> sv;
    for (auto it = fmRange.begin(); it != fmRange.end(); ++it) {
        kv.push_back(it->first);
        mv.push_back(it->second);
        sv.push_back(*it);
    }
    auto fmFromSortedVectorCopy = Map(Qt::OrderedUniqueRange, kv, mv);
    auto fmFromSortedVectorMove = Map(Qt::OrderedUniqueRange, Map::key_container_type(kv),
                                      Map::mapped_container_type(mv));
    auto fmFromSortedInitList = Map(Qt::OrderedUniqueRange, { { 1, "foo" }, { 2, "bar" } });
    auto fmFromSortedRange = Map(Qt::OrderedUniqueRange, sv.begin(), sv.end());
}

void tst_QFlatMap::constAccess()
{
    using Map = QFlatMap<QByteArray, QByteArray>;
    const Map m{ { { "foo", "FOO" }, { "bar", "BAR" } } };

    const std::vector<Map::value_type> v{ { "foo", "FOO" }, { "bar", "BAR" } };

    QCOMPARE(m.value("foo").data(), "FOO");
    QCOMPARE(m.value("bar").data(), "BAR");
    QCOMPARE(m.value("nix"), QByteArray());
    QCOMPARE(m.value("nix", "NIX").data(), "NIX");
    QCOMPARE(m["foo"].data(), "FOO");
    QCOMPARE(m["bar"].data(), "BAR");
    QCOMPARE(m["nix"], QByteArray());
    QVERIFY(m.contains("foo"));
    QVERIFY(!m.contains("nix"));
}

void tst_QFlatMap::insertion()
{
    using Map = QFlatMap<QByteArray, QByteArray>;
    Map m;
    QByteArray foo = "foo";
    m[foo] = foo.toUpper();
    m["bar"] = "BAR";
    m["baz"] = "BAZ";
    QVERIFY(m.insert("oof", "eek").second);
    QVERIFY(!m.insert("oof", "OOF").second);
    const std::vector<Map::value_type> container = { { "bla", "BLA" }, { "blubb", "BLUBB" } };
    m.insert(container.begin(), container.end());
    QCOMPARE(m.value("foo").data(), "FOO");
    QCOMPARE(m.value("bar").data(), "BAR");
    QCOMPARE(m.value("baz").data(), "BAZ");
    QCOMPARE(m.value("oof").data(), "eek");
    QCOMPARE(m.value("bla").data(), "BLA");
    QCOMPARE(m.value("blubb").data(), "BLUBB");

    Map::value_type a1[] = { { "narf", "NARF" },
                             { "zort", "ZORT" },
                             { "troz", "TROZ" } };
    Map::value_type a2[] = { { "gnampf", "GNAMPF" },
                             { "narf", "NARFFFF" },
                             { "narf", "NARFFFFF" },
                             { "narf", "NARFFFFFF" } };
    m.insert(std::begin(a1), std::end(a1));
    m.insert(Qt::OrderedUniqueRange, std::begin(a2), std::end(a2));
    QCOMPARE(m.size(), 10);
    QCOMPARE(m.value("narf").data(), "NARF");
    QCOMPARE(m.value("gnampf").data(), "GNAMPF");
}

void tst_QFlatMap::insertRValuesAndLValues()
{
    using Map = QFlatMap<QByteArray, QByteArray>;
    const QByteArray foo = QByteArrayLiteral("foo");
    const QByteArray bar = QByteArrayLiteral("bar");

    auto rvalue = [](const QByteArray &ba) { return ba; };
#define lvalue(x) x

    {
        Map m;
        QVERIFY( m.insert(lvalue(foo), lvalue(bar)).second);
        QVERIFY(!m.insert(lvalue(foo), lvalue(bar)).second);
    }

    {
        Map m;
        QVERIFY( m.insert(lvalue(foo), rvalue(bar)).second);
        QVERIFY(!m.insert(lvalue(foo), rvalue(bar)).second);
    }

    {
        Map m;
        QVERIFY( m.insert(rvalue(foo), lvalue(bar)).second);
        QVERIFY(!m.insert(rvalue(foo), lvalue(bar)).second);
    }

    {
        Map m;
        QVERIFY( m.insert(rvalue(foo), rvalue(bar)).second);
        QVERIFY(!m.insert(rvalue(foo), rvalue(bar)).second);
    }

#undef lvalue
}

void tst_QFlatMap::extraction()
{
    using Map = QFlatMap<int, QByteArray>;
    Map::key_container_type expectedKeys = { 1, 2, 3 };
    Map::mapped_container_type expectedValues = { "een", "twee", "dree" };
    Map m(Qt::OrderedUniqueRange, expectedKeys, expectedValues);
    auto keys = m.keys();
    auto values = m.values();
    QCOMPARE(keys, expectedKeys);
    QCOMPARE(values, expectedValues);
    Map::containers c = std::move(m).extract();
    QCOMPARE(c.keys, expectedKeys);
    QCOMPARE(c.values, expectedValues);
}

void tst_QFlatMap::iterators()
{
    using Map = QFlatMap<int, QByteArray>;
    auto m = Map{ Qt::OrderedUniqueRange, { { 1, "foo" }, { 2, "bar" }, { 3, "baz" } } };
    {
        // forward / backward
        Map::iterator a = m.begin();
        QVERIFY(a != m.end());
        QCOMPARE(a.key(), 1);
        QCOMPARE(a.value(), "foo");
        ++a;
        QCOMPARE(a.key(), 2);
        QCOMPARE(a.value(), "bar");
        Map::iterator b = a++;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(3, "baz"));
        QCOMPARE(std::tie(b.key(), b.value()), std::make_tuple(2, "bar"));
        QCOMPARE(++a, m.end());
        --a;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(3, "baz"));
        a.value() = "buzz";
        b = a--;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(2, "bar"));
        QCOMPARE(std::tie(b.key(), b.value()), std::make_tuple(3, "buzz"));
        b.value() = "baz";

        // random access
        a = m.begin();
        a += 2;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(3, "baz"));
        a = m.begin() + 1;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(2, "bar"));
        a = 1 + m.begin();
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(2, "bar"));
        a = m.end() - 1;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(3, "baz"));
        b = m.end();
        b -= 1;
        QCOMPARE(std::tie(b.key(), b.value()), std::make_tuple(3, "baz"));
        QCOMPARE(m.end() - m.begin(), m.size());

        // comparison
        a = m.begin() + m.size() - 1;
        b = m.end() - 1;
        QVERIFY(a == b);
        a = m.begin();
        b = m.end();
        QVERIFY(a < b);
        QVERIFY(a <= b);
        QVERIFY(b > a);
        QVERIFY(b >= a);
        a = b;
        QVERIFY(!(a < b));
        QVERIFY(a <= b);
        QVERIFY(!(b > a));
        QVERIFY(b >= a);

        // de-referencing
        a = m.begin();
        auto ref0 = *a;
        QCOMPARE(ref0.first, 1);
        QCOMPARE(ref0.second, "foo");
        auto ref1 = a[1];
        QCOMPARE(ref1.first, 2);
        QCOMPARE(ref1.second, "bar");
    }
    {
        // forward / backward
        Map::const_iterator a = m.cbegin();
        QVERIFY(a != m.cend());
        QCOMPARE(a.key(), 1);
        QCOMPARE(a.value(), "foo");
        ++a;
        QCOMPARE(a.key(), 2);
        QCOMPARE(a.value(), "bar");
        Map::const_iterator b = a++;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(3, "baz"));
        QCOMPARE(std::tie(b.key(), b.value()), std::make_tuple(2, "bar"));
        QCOMPARE(++a, m.cend());
        --a;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(3, "baz"));
        b = a--;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(2, "bar"));

        // random access
        a = m.cbegin();
        a += 2;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(3, "baz"));
        a = m.cbegin() + 1;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(2, "bar"));
        a = 1 + m.cbegin();
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(2, "bar"));
        a = m.cend() - 1;
        QCOMPARE(std::tie(a.key(), a.value()), std::make_tuple(3, "baz"));
        b = m.cend();
        b -= 1;
        QCOMPARE(std::tie(b.key(), b.value()), std::make_tuple(3, "baz"));
        QCOMPARE(m.cend() - m.cbegin(), m.size());

        // comparison
        a = m.cbegin() + m.size() - 1;
        b = m.cend() - 1;
        QVERIFY(a == b);
        a = m.cbegin();
        b = m.cend();
        QVERIFY(a < b);
        QVERIFY(a <= b);
        QVERIFY(b > a);
        QVERIFY(b >= a);
        a = b;
        QVERIFY(!(a < b));
        QVERIFY(a <= b);
        QVERIFY(!(b > a));
        QVERIFY(b >= a);

        // de-referencing
        a = m.cbegin();
        auto ref0 = *a;
        QCOMPARE(ref0.first, 1);
        QCOMPARE(ref0.second, "foo");
        auto ref1 = a[1];
        QCOMPARE(ref1.first, 2);
        QCOMPARE(ref1.second, "bar");
    }
    {
        Map::iterator it = m.begin();
        Map::const_iterator cit = it;
        Q_UNUSED(it);
        Q_UNUSED(cit);
    }
    {
        std::list<Map::value_type> revlst;
        std::copy(m.begin(), m.end(), std::front_inserter(revlst));
        std::vector<Map::value_type> v0;
        std::copy(revlst.begin(), revlst.end(), std::back_inserter(v0));
        std::vector<Map::value_type> v1;
        std::copy(m.rbegin(), m.rend(), std::back_inserter(v1));
        const Map cm = m;
        std::vector<Map::value_type> v2;
        std::copy(cm.rbegin(), cm.rend(), std::back_inserter(v2));
        std::vector<Map::value_type> v3;
        std::copy(m.crbegin(), m.crend(), std::back_inserter(v3));
        QCOMPARE(v0, v1);
        QCOMPARE(v1, v2);
        QCOMPARE(v2, v3);
    }
}

template <typename Pred>
void tst_QFlatMap::remove_if_impl(Pred p, bool removeNonEmptyValues)
{
    // empty stays empty:
    {
        QFlatMap<int, QString> m;
        QCOMPARE(m.remove_if(p), 0);
        QVERIFY(m.isEmpty());
    }
    // a matching element is removed:
    {
        {
            QFlatMap<int, QString> m;
            m.insert_or_assign(0, "");
            QCOMPARE(m.remove_if(p), 1);
            QVERIFY(m.isEmpty());
        }
        if (removeNonEmptyValues) {
            QFlatMap<int, QString> m;
            m.insert_or_assign(0, "x");
            QCOMPARE(m.remove_if(p), 1);
            QVERIFY(m.isEmpty());
        }
    }
    // a non-matching element is not removed:
    {
        {
            QFlatMap<int, QString> m;
            m.insert_or_assign(1, "");
            QCOMPARE(m.remove_if(p), 0);
            QVERIFY(m.contains(1));
            QVERIFY(m[1].isEmpty());
        }
        if (removeNonEmptyValues) {
            QFlatMap<int, QString> m;
            m.insert_or_assign(1, "x");
            QCOMPARE(m.remove_if(p), 0);
            QVERIFY(m.contains(1));
            QCOMPARE(m[1], "x");
        }
    }
    // of matching and non-matching elements, only matching ones are removed:
    {
        {
            QFlatMap<int, QString> m;
            m.insert_or_assign(0, "");
            m.insert_or_assign(1, "");
            const auto copy = m;
            QCOMPARE(m.remove_if(p), 1);
            QCOMPARE(copy.size(), 2);
            QCOMPARE(copy[0], "");
            QCOMPARE(copy[1], "");
            QCOMPARE(m.size(), 1);
            QVERIFY(m.contains(1));
            QVERIFY(m[1].isEmpty());
        }
        {
            QFlatMap<int, QString> m;
            m.insert_or_assign(1, "");
            m.insert_or_assign(2, "");
            QCOMPARE(m.remove_if(p), 1);
            QCOMPARE(m.size(), 1);
            QVERIFY(m.contains(1));
            QVERIFY(m[1].isEmpty());
        }
    }
}

void tst_QFlatMap::removal()
{
    using Map = QFlatMap<int, QByteArray>;
    Map m({ { 2, "bar" }, { 3, "baz" }, { 1, "foo" } });
    QCOMPARE(m.value(2).data(), "bar");
    QCOMPARE(m.take(2).data(), "bar");
    QVERIFY(!m.contains(2));
    QCOMPARE(m.size(), Map::size_type(2));
    QVERIFY(m.remove(1));
    QVERIFY(!m.contains(1));
    QVERIFY(!m.remove(1));
    QCOMPARE(m.size(), Map::size_type(1));
    m.clear();
    QVERIFY(m.isEmpty());
    QVERIFY(m.empty());

    m[1] = "een";
    m[2] = "twee";
    m[3] = "dree";
    auto it = m.lower_bound(1);
    QCOMPARE(it.key(), 1);
    it = m.erase(it);
    QCOMPARE(it.key(), 2);
    QVERIFY(!m.contains(1));
}

void tst_QFlatMap::statefulComparator()
{
    struct CountingCompare {
        mutable int count = 0;

        bool operator()(const QString &lhs, const QString &rhs) const
        {
            ++count;
            return lhs < rhs;
        }
    };

    using Map = QFlatMap<QString, QString, CountingCompare>;
    auto m1 = Map{ { "en", "een"}, { "to", "twee" }, { "tre", "dree" } };
    QVERIFY(m1.key_comp().count > 0);
    auto m2 = Map(m1.key_comp());
    QCOMPARE(m2.key_comp().count, m1.key_comp().count);
    m2.insert(m1.begin(), m1.end());
    QVERIFY(m2.key_comp().count > m1.key_comp().count);
}

void tst_QFlatMap::transparency_using()
{
    struct StringViewCompare
    {
        using is_transparent [[maybe_unused]] = void;
        bool operator()(QAnyStringView lhs, QAnyStringView rhs) const
        {
            return lhs < rhs;
        }
    };
    transparency_impl<StringViewCompare>();
}

void tst_QFlatMap::transparency_struct()
{
    struct StringViewCompare
    {
        struct is_transparent {};
        bool operator()(QAnyStringView lhs, QAnyStringView rhs) const
        {
            return lhs < rhs;
        }
    };
    transparency_impl<StringViewCompare>();
}

template <typename StringViewCompare>
void tst_QFlatMap::transparency_impl()
{
    using Map = QFlatMap<QString, QString, StringViewCompare>;
    auto m = Map{ { "one", "een" }, { "two", "twee" }, { "three", "dree" } };

    const QString numbers = "one two three";
    const QStringView sv1{numbers.constData(), 3};
    const QStringView sv2{numbers.constData() + 4, 3};
    const QStringView sv3{numbers.constData() + 8, 5};
    QCOMPARE(m.lower_bound(sv1).value(), "een");
    QCOMPARE(m.value(sv1), "een");
    QCOMPARE(m.lower_bound(sv2).value(), "twee");
    QCOMPARE(m.value(sv2), "twee");
    QCOMPARE(m.lower_bound(sv3).value(), "dree");
    QCOMPARE(m.value(sv3), "dree");

    QVERIFY(m.contains(sv2));
    auto twee = m.take(sv2);
    static_assert(std::is_same_v<decltype(twee), QString>);
    QCOMPARE(twee, "twee");
    QVERIFY(!m.contains(sv2));

    QVERIFY(m.contains(QLatin1String("one")));
    QVERIFY(m.remove(QAnyStringView(u8"one")));
    QVERIFY(!m.contains(QLatin1String("one")));
}

void tst_QFlatMap::try_emplace_and_insert_or_assign()
{
    using Map = QFlatMap<QByteArray, QByteArray>;

    const QByteArray foo = QByteArrayLiteral("foo");
    const qsizetype qqq_1 = 3;
    const char qqq_2 = 'q';
    const QByteArray qqq = QByteArray(qqq_1, qqq_2);

    auto sb = [] (const auto &str) { return str % ""; };
    auto rvalue = [](const auto &x) { return x; };
#define lvalue(x) x
#define CHECKS() \
    do { \
        QVERIFY(!m.try_emplace(rvalue(foo), lvalue(foo)).second); \
        QCOMPARE(m.value(foo), qqq); \
        QVERIFY(!m.try_emplace(lvalue(foo), lvalue(foo)).second); \
        QCOMPARE(m.value(foo), qqq); \
        QVERIFY(!m.try_emplace(lvalue(foo), sb(foo)).second); \
        QCOMPARE(m.value(foo), qqq); \
        QVERIFY(!m.try_emplace(rvalue(foo), sb(foo)).second); \
        QCOMPARE(m.value(foo), qqq); \
    } while (0) \
    /* end */

    {
        Map m;
        QVERIFY(m.try_emplace(lvalue(foo), lvalue(qqq)).second);
        CHECKS();
        QVERIFY(!m.insert_or_assign(lvalue(foo), lvalue(foo)).second);
        QCOMPARE(m.value(foo), foo);
    }

    {
        Map m;
        QVERIFY(m.insert_or_assign(lvalue(foo), lvalue(qqq)).second);
        CHECKS();
        QVERIFY(!m.try_emplace(lvalue(foo), lvalue(foo)).second);
        QCOMPARE(m.value(foo), qqq);
    }

    {
        Map m;
        QVERIFY(m.try_emplace(lvalue(foo), rvalue(qqq)).second);
        CHECKS();
        QVERIFY(!m.insert_or_assign(lvalue(foo), rvalue(foo)).second);
        QCOMPARE(m.value(foo), foo);
    }

    {
        Map m;
        QVERIFY(m.insert_or_assign(lvalue(foo), rvalue(qqq)).second);
        CHECKS();
        QVERIFY(!m.try_emplace(lvalue(foo), rvalue(foo)).second);
        QCOMPARE(m.value(foo), qqq);
    }

    {
        Map m;
        QVERIFY(m.try_emplace(lvalue(foo), qqq_1, qqq_2).second);
        QCOMPARE(m.value(foo), qqq);
        CHECKS();
    }

    {
        Map m;
        QVERIFY(m.try_emplace(lvalue(foo), sb(qqq)).second);
        QCOMPARE(m.value(foo), qqq);
        CHECKS();
        QVERIFY(!m.insert_or_assign(lvalue(foo), sb(foo)).second);
        QCOMPARE(m.value(foo), foo);
    }

    {
        Map m;
        QVERIFY(m.insert_or_assign(lvalue(foo), sb(qqq)).second);
        QCOMPARE(m.value(foo), qqq);
        CHECKS();
        QVERIFY(!m.try_emplace(lvalue(foo), sb(foo)).second);
        QCOMPARE(m.value(foo), qqq);
    }

    {
        Map m;
        QVERIFY(m.try_emplace(rvalue(foo), lvalue(qqq)).second);
        CHECKS();
        QVERIFY(!m.insert_or_assign(rvalue(foo), lvalue(foo)).second);
        QCOMPARE(m.value(foo), foo);
    }

    {
        Map m;
        QVERIFY(m.insert_or_assign(rvalue(foo), lvalue(qqq)).second);
        CHECKS();
        QVERIFY(!m.try_emplace(rvalue(foo), lvalue(foo)).second);
        QCOMPARE(m.value(foo), qqq);
    }

    {
        Map m;
        QVERIFY(m.try_emplace(rvalue(foo), rvalue(qqq)).second);
        CHECKS();
        QVERIFY(!m.insert_or_assign(rvalue(foo), rvalue(foo)).second);
        QCOMPARE(m.value(foo), foo);
    }

    {
        Map m;
        QVERIFY(m.insert_or_assign(rvalue(foo), rvalue(qqq)).second);
        CHECKS();
        QVERIFY(!m.try_emplace(rvalue(foo), rvalue(foo)).second);
        QCOMPARE(m.value(foo), qqq);
    }

    {
        Map m;
        QVERIFY(m.try_emplace(rvalue(foo), qqq_1, qqq_2).second);
        QCOMPARE(m.value(foo), qqq);
        CHECKS();
    }

    {
        Map m;
        QVERIFY(m.try_emplace(rvalue(foo), sb(qqq)).second);
        QCOMPARE(m.value(foo), qqq);
        CHECKS();
        QVERIFY(!m.insert_or_assign(rvalue(foo), sb(foo)).second);
        QCOMPARE(m.value(foo), foo);
    }

    {
        Map m;
        QVERIFY(m.insert_or_assign(rvalue(foo), sb(qqq)).second);
        QCOMPARE(m.value(foo), qqq);
        CHECKS();
        QVERIFY(!m.try_emplace(rvalue(foo), sb(foo)).second);
        QCOMPARE(m.value(foo), qqq);
    }
#undef CHECKS
#undef lvalue
}

void tst_QFlatMap::viewIterators()
{
    using Map = QFlatMap<QByteArray, QByteArray>;
    Map m({ { "yksi", "een"}, { "kaksi", "twee" }, { "kolme", "dree" } });
    {
        std::vector<QByteArray> keys;
        std::transform(m.begin(), m.end(), std::back_inserter(keys),
                       [](const Map::value_type &v)
                       {
                           return v.first;
                       });
        auto it = keys.begin();
        QCOMPARE(*it, "kaksi");
        QCOMPARE(it->size(), 5);
        ++it;
        QCOMPARE(*it, "kolme");
        it++;
        QCOMPARE(*it, "yksi");
        ++it;
        QCOMPARE(it, keys.end());
        --it;
        QCOMPARE(*it, "yksi");
        it--;
        QCOMPARE(*it, "kolme");
    }
    {
        std::vector<QByteArray> values;
        std::transform(m.begin(), m.end(), std::back_inserter(values),
                       [](const Map::value_type &v)
                       {
                           return v.second;
                       });
        auto it = values.begin();
        QCOMPARE(*it, "twee");
        QCOMPARE(it->size(), 4);
        ++it;
        QCOMPARE(*it, "dree");
        it++;
        QCOMPARE(*it, "een");
        ++it;
        QCOMPARE(it, values.end());
        --it;
        QCOMPARE(*it, "een");
        it--;
        QCOMPARE(*it, "dree");
    }
}

void tst_QFlatMap::varLengthArray()
{
    using Map = QVarLengthFlatMap<int, QByteArray, 1024>;
    Map m(Qt::OrderedUniqueRange, { { 2, "twee" } });
    m.insert_or_assign(1, "een");
    m.remove(1);
    QVERIFY(!m.isEmpty());
    m.remove(2);
    QVERIFY(m.isEmpty());
}

QTEST_APPLESS_MAIN(tst_QFlatMap)
#include "tst_qflatmap.moc"