wifi: Add a class for optional fields with presence indicator flag

src/wifi/CMakeLists.txt

@@ -295,6 +295,7 @@ set(header_files
     model/wifi-mpdu-type.h
     model/wifi-mpdu.h
     model/wifi-net-device.h
+    model/wifi-opt-field.h
     model/wifi-phy-band.h
     model/wifi-phy-common.h
     model/wifi-phy-listener.h

src/wifi/model/wifi-opt-field.h

@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2024 Universita' degli Studi di Napoli Federico II
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Stefano Avallone <stavallo@unina.it>
+ */
+
+#ifndef WIFI_OPT_FIELD_H
+#define WIFI_OPT_FIELD_H
+
+#include <functional>
+#include <optional>
+
+namespace ns3
+{
+
+/**
+ * \ingroup wifi
+ *
+ * OptFieldWithPresenceInd is a class modeling an optional field (in an Information Element, a
+ * management frame, etc.) having an associated Presence Indicator bit. This class is a wrapper
+ * around std::optional (most of its functions are exposed, more can be added if needed) that
+ * additionally sets the Presence Indicator flag appropriately when operations like reset or
+ * assignment of a value are performed on the optional field.
+ */
+template <typename T>
+class OptFieldWithPresenceInd
+{
+  public:
+    /// @brief constructor
+    /// @param presenceFlag the Presence Indicator flag
+    OptFieldWithPresenceInd(bool& presenceFlag);
+
+    /// @brief Destroy the value (if any) contained in the optional field.
+    /// @return a reference to this object
+    constexpr OptFieldWithPresenceInd& operator=(std::nullopt_t);
+
+    /// @brief Assign the given value to the optional field
+    /// @param other the given value
+    /// @return a reference to this object
+    constexpr OptFieldWithPresenceInd& operator=(const std::optional<T>& other);
+
+    /// @brief Assign the given value to the optional field
+    /// @param other the given value
+    /// @return a reference to this object
+    constexpr OptFieldWithPresenceInd& operator=(std::optional<T>&& other);
+
+    /// @brief Operator bool
+    /// @return whether this object contains a value
+    constexpr explicit operator bool() const;
+
+    /// @brief Check whether this object contains a value
+    /// @return whether this object contains a value
+    constexpr bool has_value() const;
+
+    /// @return a pointer to the contained value
+    constexpr const T* operator->() const;
+
+    /// @return a pointer to the contained value
+    constexpr T* operator->();
+
+    /// @return a reference to the contained value
+    constexpr const T& operator*() const;
+
+    /// @return a reference to the contained value
+    constexpr T& operator*();
+
+    /// @brief Construct the contained value in-place
+    /// @tparam Args the type of arguments to pass to the constructor
+    /// @param args the arguments to pass to the constructor
+    /// @return a reference to the new contained value
+    template <class... Args>
+    constexpr T& emplace(Args&&... args);
+
+    /// @brief Destroy the value (if any) contained in the optional field
+    constexpr void reset();
+
+  private:
+    std::optional<T> m_field;                    ///< the optional field
+    std::reference_wrapper<bool> m_presenceFlag; ///< the Presence Indicator flag
+};
+
+} // namespace ns3
+
+/***************************************************************
+ *  Implementation of the templates declared above.
+ ***************************************************************/
+
+namespace ns3
+{
+
+template <typename T>
+OptFieldWithPresenceInd<T>::OptFieldWithPresenceInd(bool& presenceFlag)
+    : m_presenceFlag(presenceFlag)
+{
+    m_presenceFlag.get() = false;
+}
+
+template <typename T>
+constexpr OptFieldWithPresenceInd<T>&
+OptFieldWithPresenceInd<T>::operator=(std::nullopt_t)
+{
+    m_field.reset();
+    m_presenceFlag.get() = false;
+    return *this;
+}
+
+template <typename T>
+constexpr OptFieldWithPresenceInd<T>&
+OptFieldWithPresenceInd<T>::operator=(const std::optional<T>& other)
+{
+    m_field = other;
+    m_presenceFlag.get() = other.has_value();
+    return *this;
+}
+
+template <typename T>
+constexpr OptFieldWithPresenceInd<T>&
+OptFieldWithPresenceInd<T>::operator=(std::optional<T>&& other)
+{
+    m_field = std::move(other);
+    m_presenceFlag.get() = other.has_value();
+    return *this;
+}
+
+template <typename T>
+constexpr OptFieldWithPresenceInd<T>::operator bool() const
+{
+    return m_field.has_value();
+}
+
+template <typename T>
+constexpr bool
+OptFieldWithPresenceInd<T>::has_value() const
+{
+    return m_field.has_value();
+}
+
+template <typename T>
+constexpr const T*
+OptFieldWithPresenceInd<T>::operator->() const
+{
+    return &(*m_field);
+}
+
+template <typename T>
+constexpr T*
+OptFieldWithPresenceInd<T>::operator->()
+{
+    return &(*m_field);
+}
+
+template <typename T>
+constexpr const T&
+OptFieldWithPresenceInd<T>::operator*() const
+{
+    return *m_field;
+}
+
+template <typename T>
+constexpr T&
+OptFieldWithPresenceInd<T>::operator*()
+{
+    return *m_field;
+}
+
+template <typename T>
+template <class... Args>
+constexpr T&
+OptFieldWithPresenceInd<T>::emplace(Args&&... args)
+{
+    m_field.emplace(std::forward<Args>(args)...);
+    m_presenceFlag.get() = true;
+    return *m_field;
+}
+
+template <typename T>
+constexpr void
+OptFieldWithPresenceInd<T>::reset()
+{
+    m_field.reset();
+    m_presenceFlag.get() = false;
+}
+
+} // namespace ns3
+
+#endif /* WIFI_OPT_FIELD_H */

utils/codespell-ignored-lines

@@ -81,6 +81,7 @@ Network Animator nam.  It is not possible to run a simulation
  * Copyright (c) 2022 Universita' degli Studi di Napoli Federico II
  * Copyright (c) 2022 Universita' degli Studi di Napoli "Federico II"
  * Copyright (c) 2023 Universita' degli Studi di Napoli Federico II
+ * Copyright (c) 2024 Universita' degli Studi di Napoli Federico II
 
 ./src/core/examples/hash-example.cc
 6ed21de2  brand-newness       peripherial