Added de-reference operators to observer_ptr and added tests

Author: cschreib

include/oup/observable_unique_ptr.hpp

@@ -363,6 +363,25 @@ class observer_ptr : private std::weak_ptr<T> {
         return std::weak_ptr<T>::lock().get();
     }
 
+    /// Get a reference to the pointed object (undefined behavior if deleted).
+    /** \return A reference to the pointed object
+    *   \note Using this function if expired() is 'true' will leave to undefined behavior.
+    */
+    T& operator*() const noexcept {
+        return *std::weak_ptr<T>::lock().get();
+    }
+
+    /// Get a non-owning raw pointer to the pointed object, or nullptr if deleted.
+    /** \return 'nullptr' if expired() is 'true', or the pointed object otherwise
+    *   \note Contrary to std::weak_ptr::lock(), this does not extend the lifetime
+    *         of the pointed object. Therefore, when calling this function, you must
+    *         make sure that the owning observable_unique_ptr will not be reset until
+    *         you are done using the raw pointer.
+    */
+    T* operator->() const noexcept {
+        return std::weak_ptr<T>::lock().get();
+    }
+
     /// Swap the content of this pointer with that of another pointer.
     /** \param other The other pointer to swap with
     */

tests/runtime_tests.cpp

@@ -523,6 +523,12 @@ TEST_CASE("owner swap two instances with deleter", "[owner_utility]") {
     REQUIRE(instances_deleter == 0);
 }
 
+TEST_CASE("owner dereference", "[owner_utility]") {
+    test_ptr ptr(new test_object);
+    REQUIRE(ptr->state_ == 1337);
+    REQUIRE((*ptr).state_ == 1337);
+}
+
 TEST_CASE("make observable", "[make_observable_unique]") {
     {
         test_ptr ptr = oup::make_observable_unique<test_object>();
@@ -743,6 +749,13 @@ TEST_CASE("observer swap two different instances", "[observer_utility]") {
     REQUIRE(instances == 0);
 }
 
+TEST_CASE("observer dereference", "[observer_utility]") {
+    test_ptr ptr_owner(new test_object);
+    test_optr ptr(ptr_owner);
+    REQUIRE(ptr->state_ == 1337);
+    REQUIRE((*ptr).state_ == 1337);
+}
+
 TEST_CASE("observer comparison valid ptr vs nullptr", "[observer_comparison]") {
     test_ptr ptr_owner(new test_object);
     test_optr ptr(ptr_owner);

tests/tests_common.hpp

@@ -8,6 +8,8 @@ int instances_thrower = 0;
 int instances_deleter = 0;
 
 struct test_object {
+    int state_ = 1337;
+
     test_object() noexcept { ++instances; }
     virtual ~test_object() noexcept { --instances; }