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diff --git a/src/qmlcompiler/qdeferredpointer_p.h b/src/qmlcompiler/qdeferredpointer_p.h
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+++ b/src/qmlcompiler/qdeferredpointer_p.h
@@ -0,0 +1,253 @@
+// Copyright (C) 2020 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#ifndef QDEFERREDPOINTER_P_H
+#define QDEFERREDPOINTER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+
+#include <qtqmlcompilerexports.h>
+
+#include <QtCore/private/qglobal_p.h>
+#include <QtCore/qsharedpointer.h>
+
+QT_BEGIN_NAMESPACE
+
+template<typename T>
+class QDeferredSharedPointer;
+
+template<typename T>
+class QDeferredWeakPointer;
+
+template<typename T>
+class QDeferredFactory
+{
+public:
+    bool isValid() const;
+
+private:
+    friend class QDeferredSharedPointer<const T>;
+    friend class QDeferredWeakPointer<const T>;
+    friend class QDeferredSharedPointer<T>;
+    friend class QDeferredWeakPointer<T>;
+    void populate(const QSharedPointer<T> &) const;
+};
+
+template<typename T>
+class QDeferredSharedPointer
+{
+public:
+    using Factory = QDeferredFactory<std::remove_const_t<T>>;
+
+    Q_NODISCARD_CTOR QDeferredSharedPointer() = default;
+
+    Q_NODISCARD_CTOR QDeferredSharedPointer(QSharedPointer<T> data)
+        : m_data(std::move(data))
+    {}
+
+    Q_NODISCARD_CTOR QDeferredSharedPointer(QWeakPointer<T> data)
+        : m_data(std::move(data))
+    {}
+
+    Q_NODISCARD_CTOR QDeferredSharedPointer(QSharedPointer<T> data, QSharedPointer<Factory> factory)
+        : m_data(std::move(data)), m_factory(std::move(factory))
+    {
+        // You have to provide a valid pointer if you provide a factory. We cannot allocate the
+        // pointer for you because then two copies of the same QDeferredSharedPointer will diverge
+        // and lazy-load two separate data objects.
+        Q_ASSERT(!m_data.isNull() || m_factory.isNull());
+    }
+
+    [[nodiscard]] operator QSharedPointer<T>() const
+    {
+        lazyLoad();
+        return m_data;
+    }
+
+    operator QDeferredSharedPointer<const T>() const { return { m_data, m_factory }; }
+
+    [[nodiscard]] T &operator*() const { return QSharedPointer<T>(*this).operator*(); }
+    [[nodiscard]] T *operator->() const { return QSharedPointer<T>(*this).operator->(); }
+
+    bool isNull() const
+    {
+        return m_data.isNull();
+    }
+
+    explicit operator bool() const noexcept { return !isNull(); }
+    bool operator !() const noexcept { return isNull(); }
+
+    [[nodiscard]] T *data() const { return QSharedPointer<T>(*this).data(); }
+    [[nodiscard]] T *get() const { return data(); }
+
+    friend size_t qHash(const QDeferredSharedPointer &ptr, size_t seed = 0)
+    {
+        // This is a hash of the pointer, not the data.
+        return qHash(ptr.m_data, seed);
+    }
+
+    friend bool operator==(const QDeferredSharedPointer &a, const QDeferredSharedPointer &b)
+    {
+        // This is a comparison of the pointers, not their data. As we require the pointers to
+        // be given in the ctor, we can do this.
+        return a.m_data == b.m_data;
+    }
+
+    friend bool operator!=(const QDeferredSharedPointer &a, const QDeferredSharedPointer &b)
+    {
+        return !(a == b);
+    }
+
+    friend bool operator<(const QDeferredSharedPointer &a, const QDeferredSharedPointer &b)
+    {
+        return a.m_data < b.m_data;
+    }
+
+    friend bool operator<=(const QDeferredSharedPointer &a, const QDeferredSharedPointer &b)
+    {
+        return a.m_data <= b.m_data;
+    }
+
+    friend bool operator>(const QDeferredSharedPointer &a, const QDeferredSharedPointer &b)
+    {
+        return a.m_data > b.m_data;
+    }
+
+    friend bool operator>=(const QDeferredSharedPointer &a, const QDeferredSharedPointer &b)
+    {
+        return a.m_data >= b.m_data;
+    }
+
+    template <typename U>
+    friend bool operator==(const QDeferredSharedPointer &a, const QSharedPointer<U> &b)
+    {
+        return a.m_data == b;
+    }
+
+    template <typename U>
+    friend bool operator!=(const QDeferredSharedPointer &a, const QSharedPointer<U> &b)
+    {
+        return !(a == b);
+    }
+
+    template <typename U>
+    friend bool operator==(const QSharedPointer<U> &a, const QDeferredSharedPointer &b)
+    {
+        return b == a;
+    }
+
+    template <typename U>
+    friend bool operator!=(const QSharedPointer<U> &a, const QDeferredSharedPointer &b)
+    {
+        return b != a;
+    }
+
+    Factory *factory() const
+    {
+        return (m_factory && m_factory->isValid()) ? m_factory.data() : nullptr;
+    }
+
+    void resetFactory(const Factory& newFactory) const
+    {
+        const bool wasAlreadyLoaded = !factory();
+        *m_factory = newFactory;
+        if (wasAlreadyLoaded)
+            lazyLoad();
+    }
+
+private:
+    friend class QDeferredWeakPointer<T>;
+
+    void lazyLoad() const
+    {
+        if (Factory *f = factory()) {
+            Factory localFactory;
+            std::swap(localFactory, *f); // Swap before executing, to avoid recursion
+            localFactory.populate(m_data.template constCast<std::remove_const_t<T>>());
+        }
+    }
+
+    QSharedPointer<T> m_data;
+    QSharedPointer<Factory> m_factory;
+};
+
+template<typename T>
+class QDeferredWeakPointer
+{
+public:
+    using Factory = QDeferredFactory<std::remove_const_t<T>>;
+
+    Q_NODISCARD_CTOR QDeferredWeakPointer() = default;
+
+    Q_NODISCARD_CTOR QDeferredWeakPointer(const QDeferredSharedPointer<T> &strong)
+        : m_data(strong.m_data), m_factory(strong.m_factory)
+    {
+    }
+
+    Q_NODISCARD_CTOR QDeferredWeakPointer(QWeakPointer<T> data, QWeakPointer<Factory> factory)
+        : m_data(data), m_factory(factory)
+    {}
+
+    [[nodiscard]] operator QWeakPointer<T>() const
+    {
+        lazyLoad();
+        return m_data;
+    }
+
+    [[nodiscard]] operator QDeferredSharedPointer<T>() const
+    {
+        return QDeferredSharedPointer<T>(m_data.toStrongRef(), m_factory.toStrongRef());
+    }
+
+    operator QDeferredWeakPointer<const T>() const { return {m_data, m_factory}; }
+
+    [[nodiscard]] QSharedPointer<T> toStrongRef() const
+    {
+        return QWeakPointer<T>(*this).toStrongRef();
+    }
+
+    bool isNull() const { return m_data.isNull(); }
+
+    explicit operator bool() const noexcept { return !isNull(); }
+    bool operator !() const noexcept { return isNull(); }
+
+    friend bool operator==(const QDeferredWeakPointer &a, const QDeferredWeakPointer &b)
+    {
+        return a.m_data == b.m_data;
+    }
+
+    friend bool operator!=(const QDeferredWeakPointer &a, const QDeferredWeakPointer &b)
+    {
+        return !(a == b);
+    }
+
+private:
+    void lazyLoad() const
+    {
+        if (m_factory) {
+            auto factory = m_factory.toStrongRef();
+            if (factory->isValid()) {
+                Factory localFactory;
+                std::swap(localFactory, *factory); // Swap before executing, to avoid recursion
+                localFactory.populate(
+                        m_data.toStrongRef().template constCast<std::remove_const_t<T>>());
+            }
+        }
+    }
+
+    QWeakPointer<T> m_data;
+    QWeakPointer<Factory> m_factory;
+};
+
+
+QT_END_NAMESPACE
+
+#endif // QDEFERREDPOINTER_P_H