Enable default cetl::pmr::PmrInterfaceDeleter ctor. #verification #…

…docs #sonar

cetlvast/suites/unittest/pmr/test_pmr_interface_ptr.cpp

@@ -235,4 +235,17 @@ TEST_F(TestPmrInterfacePtr, make_unique_myobj_ctor_throws)
 #endif
 }
 
+TEST_F(TestPmrInterfacePtr, initially_empty_with_default_deleter)
+{
+    cetl::pmr::polymorphic_allocator<MyObject> alloc{get_mr()};
+
+    // 1. Create initially empty interface pointer.
+    cetl::pmr::InterfacePtr<INamed> obj0;
+    EXPECT_THAT(obj0, IsNull());
+
+    // 2. Now assign a new instance.
+    obj0 = cetl::pmr::InterfaceFactory::make_unique<INamed>(alloc, "obj0");
+    EXPECT_THAT(obj0, NotNull());
+}
+
 }  // namespace

include/cetl/pmr/interface_ptr.hpp

@@ -29,6 +29,12 @@ template <typename Interface>
 class PmrInterfaceDeleter final
 {
 public:
+    /// Constructs empty no-operation deleter.
+    ///
+    /// Useful for initially empty `InterfacePtr` instance without deleter attached.
+    ///
+    PmrInterfaceDeleter() = default;
+
     /// Constructs a Concrete type-erased deleter for the given interface type.
     ///
     /// @tparam PmrAllocator The type of the polymorphic allocator to use for deallocation.
@@ -51,7 +57,12 @@ class PmrInterfaceDeleter final
     ///
     void operator()(Interface* ptr) noexcept
     {
-        deleter_(ptr);
+        CETL_DEBUG_ASSERT((nullptr != ptr) == static_cast<bool>(deleter_), "Empty deleter is fine for null ptr!");
+
+        if ((nullptr != ptr) && static_cast<bool>(deleter_))
+        {
+            deleter_(ptr);
+        }
     }
 
     // Below convertor constructor is only possible with enabled PMR at `function`.
@@ -143,7 +154,7 @@ class InterfaceFactory final
         using Concrete = typename PmrAllocator::value_type;
 
     public:
-        ConcreteRaii(PmrAllocator& pmr_allocator)
+        explicit ConcreteRaii(PmrAllocator& pmr_allocator)
             : concrete_{pmr_allocator.allocate(1)}
             , constructed_{false}
             , pmr_allocator_{pmr_allocator}