+/*
+ * Copyright (c) 2022 Francis Deslauriers <francis.deslauriers@efficios.com>
+ * Copyright (c) 2023 Philippe Proulx <pproulx@efficios.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef BABELTRACE_CPP_COMMON_BT2_BORROWED_OBJECT_ITERATOR_HPP
+#define BABELTRACE_CPP_COMMON_BT2_BORROWED_OBJECT_ITERATOR_HPP
+
+#include <cstdint>
+#include <type_traits>
+#include <utility>
+
+#include "common/assert.h"
+
+#include "borrowed-object-proxy.hpp"
+
+namespace bt2 {
+
+/*
+ * An iterator class to iterate an instance of a borrowed object
+ * container of type `ContainerT`.
+ *
+ * `ContainerT` must implement:
+ *
+ * // Returns the number of contained borrowed objects.
+ * std::uint64_t length() const noexcept;
+ *
+ * // Returns the borrowed object at index `i`.
+ * SomeObject operator[](std::uint64_t i) const noexcept;
+ */
+template <typename ContainerT>
+class BorrowedObjectIterator final
+{
+ friend ContainerT;
+
+public:
+ using Object = typename std::remove_reference<
+ decltype(std::declval<ContainerT>()[std::declval<std::uint64_t>()])>::type;
+
+private:
+ explicit BorrowedObjectIterator(const ContainerT container, const uint64_t idx) :
+ _mContainer {container}, _mIdx {idx}
+ {
+ }
+
+public:
+ BorrowedObjectIterator& operator++() noexcept
+ {
+ ++_mIdx;
+ return *this;
+ }
+
+ BorrowedObjectIterator operator++(int) noexcept
+ {
+ const auto tmp = *this;
+
+ ++(*this);
+ return tmp;
+ }
+
+ bool operator==(const BorrowedObjectIterator& other) const noexcept
+ {
+ BT_ASSERT_DBG(_mContainer.isSame(other._mContainer));
+ return _mIdx == other._mIdx;
+ }
+
+ bool operator!=(const BorrowedObjectIterator& other) const noexcept
+ {
+ return !(*this == other);
+ }
+
+ Object operator*() const noexcept
+ {
+ BT_ASSERT_DBG(_mIdx < _mContainer.length());
+ return _mContainer[_mIdx];
+ }
+
+ BorrowedObjectProxy<Object> operator->() const noexcept
+ {
+ return BorrowedObjectProxy<Object> {(**this).libObjPtr()};
+ }
+
+private:
+ ContainerT _mContainer;
+ std::uint64_t _mIdx;
+};
+
+} /* namespace bt2 */
+
+#endif /* BABELTRACE_CPP_COMMON_BT2_BORROWED_OBJECT_ITERATOR_HPP */