From 9df6b248e371ad45b1972b1f5bb79ec22271a01c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20LAIGRE?= <slaigre@silicom.fr>
Date: Tue, 21 Dec 2021 10:38:55 +0100
Subject: [PATCH] Add casts for std::unique_ptr
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Signed-off-by: Sébastien LAIGRE <slaigre@silicom.fr>
---
 .../powsybl/stdcxx/{upcast.hpp => cast.hpp}   | 11 +++
 src/iidm/BusBreakerVoltageLevelViews.cpp      |  2 +-
 src/iidm/CalculatedBus.cpp                    |  2 +-
 src/iidm/ConfiguredBus.cpp                    |  2 +-
 src/iidm/NodeBreakerVoltageLevelViews.cpp     |  2 +-
 test/stdcxx/CMakeLists.txt                    |  1 +
 test/stdcxx/CastTest.cpp                      | 84 +++++++++++++++++++
 7 files changed, 100 insertions(+), 4 deletions(-)
 rename include/powsybl/stdcxx/{upcast.hpp => cast.hpp} (54%)
 create mode 100644 test/stdcxx/CastTest.cpp

diff --git a/include/powsybl/stdcxx/upcast.hpp b/include/powsybl/stdcxx/cast.hpp
similarity index 54%
rename from include/powsybl/stdcxx/upcast.hpp
rename to include/powsybl/stdcxx/cast.hpp
index 3f8359863..87d3729c9 100644
--- a/include/powsybl/stdcxx/upcast.hpp
+++ b/include/powsybl/stdcxx/cast.hpp
@@ -8,10 +8,21 @@
 #ifndef POWSYBL_STDCXX_UPCAST_HPP
 #define POWSYBL_STDCXX_UPCAST_HPP
 
+#include <memory>
 #include <type_traits>
 
 namespace stdcxx {
 
+template <typename Derived, typename Base, typename = typename std::enable_if<std::is_base_of<Base, Derived>::value>::type>
+std::unique_ptr<Derived> downcast(std::unique_ptr<Base>& ptr) {
+    return std::unique_ptr<Derived>(dynamic_cast<Derived*>(ptr.release()));
+}
+
+template <typename Base, typename Derived, typename = typename std::enable_if<std::is_base_of<Base, Derived>::value>::type>
+std::unique_ptr<Base> upcast(std::unique_ptr<Derived>& ptr) {
+    return std::unique_ptr<Base>(ptr.release());
+}
+
 template <typename Derived, typename Base, typename = typename std::enable_if<std::is_base_of<Base, Derived>::value>::type>
 const Base& upcast(const Derived& value) {
     return value;
diff --git a/src/iidm/BusBreakerVoltageLevelViews.cpp b/src/iidm/BusBreakerVoltageLevelViews.cpp
index 508ea1e9c..668eaac90 100644
--- a/src/iidm/BusBreakerVoltageLevelViews.cpp
+++ b/src/iidm/BusBreakerVoltageLevelViews.cpp
@@ -8,7 +8,7 @@
 #include "BusBreakerVoltageLevelViews.hpp"
 
 #include <powsybl/iidm/Switch.hpp>
-#include <powsybl/stdcxx/upcast.hpp>
+#include <powsybl/stdcxx/cast.hpp>
 
 #include "BusBreakerVoltageLevel.hpp"
 #include "BusBreakerVoltageLevelTopology.hpp"
diff --git a/src/iidm/CalculatedBus.cpp b/src/iidm/CalculatedBus.cpp
index f7d9e41bd..30652f323 100644
--- a/src/iidm/CalculatedBus.cpp
+++ b/src/iidm/CalculatedBus.cpp
@@ -11,8 +11,8 @@
 #include <powsybl/iidm/Switch.hpp>
 #include <powsybl/iidm/SynchronousComponentsManager.hpp>
 #include <powsybl/iidm/TopologyVisitor.hpp>
+#include <powsybl/stdcxx/cast.hpp>
 #include <powsybl/stdcxx/math.hpp>
-#include <powsybl/stdcxx/upcast.hpp>
 
 #include "NodeBreakerVoltageLevel.hpp"
 #include "NodeTerminal.hpp"
diff --git a/src/iidm/ConfiguredBus.cpp b/src/iidm/ConfiguredBus.cpp
index d49de45d7..3b8dcc7dd 100644
--- a/src/iidm/ConfiguredBus.cpp
+++ b/src/iidm/ConfiguredBus.cpp
@@ -16,10 +16,10 @@
 #include <powsybl/iidm/SynchronousComponentsManager.hpp>
 #include <powsybl/iidm/TopologyVisitor.hpp>
 #include <powsybl/iidm/ValidationUtils.hpp>
+#include <powsybl/stdcxx/cast.hpp>
 #include <powsybl/stdcxx/format.hpp>
 #include <powsybl/stdcxx/math.hpp>
 #include <powsybl/stdcxx/memory.hpp>
-#include <powsybl/stdcxx/upcast.hpp>
 
 #include "BusBreakerVoltageLevel.hpp"
 #include "BusTerminal.hpp"
diff --git a/src/iidm/NodeBreakerVoltageLevelViews.cpp b/src/iidm/NodeBreakerVoltageLevelViews.cpp
index ac63cfccf..e43dd82fb 100644
--- a/src/iidm/NodeBreakerVoltageLevelViews.cpp
+++ b/src/iidm/NodeBreakerVoltageLevelViews.cpp
@@ -9,7 +9,7 @@
 
 #include <powsybl/iidm/BusbarSection.hpp>
 #include <powsybl/iidm/Switch.hpp>
-#include <powsybl/stdcxx/upcast.hpp>
+#include <powsybl/stdcxx/cast.hpp>
 
 #include "CalculatedBus.hpp"
 #include "NodeBreakerVoltageLevel.hpp"
diff --git a/test/stdcxx/CMakeLists.txt b/test/stdcxx/CMakeLists.txt
index 99c710641..2485417d5 100644
--- a/test/stdcxx/CMakeLists.txt
+++ b/test/stdcxx/CMakeLists.txt
@@ -7,6 +7,7 @@
 
 set(UNIT_TEST_SOURCES
     stdcxx.cpp
+    CastTest.cpp
     DateTimeTest.cpp
     DemangleTest.cpp
     MathTest.cpp
diff --git a/test/stdcxx/CastTest.cpp b/test/stdcxx/CastTest.cpp
new file mode 100644
index 000000000..915858a23
--- /dev/null
+++ b/test/stdcxx/CastTest.cpp
@@ -0,0 +1,84 @@
+/**
+ * Copyright (c) 2021, RTE (http://www.rte-france.com)
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <memory>
+
+#include <boost/test/unit_test.hpp>
+
+#include <powsybl/stdcxx/cast.hpp>
+#include <powsybl/stdcxx/make_unique.hpp>
+
+namespace stdcxx {
+
+BOOST_AUTO_TEST_SUITE(CaseTestSuite)
+
+class BaseClass {
+public:
+    BaseClass() = default;
+
+    virtual ~BaseClass() = default;
+
+    int getBaseAttr() const;
+
+    void setBaseAttr(int newValue);
+
+private:
+    int m_baseAttr = 1;
+};
+
+int BaseClass::getBaseAttr() const {
+    return m_baseAttr;
+}
+
+void BaseClass::setBaseAttr(int newValue) {
+    m_baseAttr = newValue;
+}
+
+class DerivedClass : public BaseClass {
+public:
+    DerivedClass() = default;
+
+    ~DerivedClass() override = default;
+
+    int getDerivedAttr() const;
+
+    void setDerivedAttr(int newValue);
+
+private:
+    int m_derivedAttr = 2;
+};
+
+int DerivedClass::getDerivedAttr() const {
+    return m_derivedAttr;
+}
+
+void DerivedClass::setDerivedAttr(int newValue) {
+    m_derivedAttr = newValue;
+}
+
+BOOST_AUTO_TEST_CASE(unique_ptrCastTest) {
+    std::unique_ptr<BaseClass> basePtr = stdcxx::make_unique<DerivedClass>();
+    BOOST_CHECK_EQUAL(1, basePtr->getBaseAttr());
+    basePtr->setBaseAttr(11);
+    BOOST_CHECK_EQUAL(11, basePtr->getBaseAttr());
+
+    std::unique_ptr<DerivedClass> derivedPtr = stdcxx::downcast<DerivedClass>(basePtr);
+    BOOST_CHECK(!basePtr);
+    BOOST_CHECK_EQUAL(11, derivedPtr->getBaseAttr());
+    BOOST_CHECK_EQUAL(2, derivedPtr->getDerivedAttr());
+    derivedPtr->setBaseAttr(111);
+    derivedPtr->setDerivedAttr(22);
+    BOOST_CHECK_EQUAL(22, derivedPtr->getDerivedAttr());
+
+    std::unique_ptr<BaseClass> otherBasePtr = stdcxx::upcast<BaseClass>(derivedPtr);
+    BOOST_CHECK(!derivedPtr);
+    BOOST_CHECK_EQUAL(111, otherBasePtr->getBaseAttr());
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}  // namespace stdcxx