Repo sync for protected branch

docs/error-messages/compiler-warnings/compiler-warning-level-2-c4150.md

@@ -1,30 +1,84 @@
 ---
 description: "Learn more about: Compiler Warning (level 2) C4150"
-title: "Compiler Warning (level 2) C4150"
+title: Compiler warning (level 2) C4150
 ms.date: "11/04/2016"
 f1_keywords: ["C4150"]
 helpviewer_keywords: ["C4150"]
-ms.assetid: ff1760ec-0d9f-4d45-b797-94261624becf
 ---
 # Compiler Warning (level 2) C4150
 
-deletion of pointer to incomplete type 'type'; no destructor called
+> deletion of pointer to incomplete type 'type'; no destructor called
 
-The **`delete`** operator is called to delete a type that was declared but not defined, so the compiler cannot find a destructor.
+The `delete` operator is called to delete a type that was declared but not defined. The compiler can't find the destructor to call because the definition isn't in the same translation unit as the `delete`.
 
-The following sample generates C4150:
+## Example
+
+The following sample generates C4150 by declaring but not defining `class IncClass`:
 
 ```cpp
-// C4150.cpp
 // compile with: /W2
-class  IncClass;
+class IncClass;
+
+void NoDestruct( IncClass* pIncClass )
+{
+   delete pIncClass; // C4150
+}
+```
+
+To fix the issue, put the definition of `IncClass` in the same file as the `delete`. If the class is declared in a header file, it can be added to the file using `#include`. If the class isn't declared in a header file, the `NoDestruct` function definition may need to be moved into the same file as the `IncClass` definition.
+
+```cpp
+// compile with: /W2
+#include "IncClass.h"
 
 void NoDestruct( IncClass* pIncClass )
 {
    delete pIncClass;
-} // C4150, define class to resolve
+}
+```
+
+C4150 will be emitted when the class is defined after the destructor call in the same file. In the following example `IncClass` is declared before being used, but defined after the `delete`:
+
+```cpp
+// C4150.cpp
+// compile with: /W2
+class IncClass;
 
-int main()
+void NoDestruct( IncClass* pIncClass )
 {
+   delete pIncClass; // C4150
 }
+
+class IncClass
+{
+public:
+    IncClass() = default;
+    ~IncClass() = default;
+};
 ```
+In this scenario, the use of `delete` needs to be after the class definition.
+```cpp
+// C4150.cpp
+// compile with: /W2
+class  IncClass;
+
+void NoDestruct( IncClass* pIncClass );
+
+class IncClass
+{
+public:
+    IncClass() = default;
+    ~IncClass() = default;
+};
+
+void NoDestruct( IncClass* pIncClass )
+{
+   delete pIncClass;
+}
+
+```
+
+## See also
+
+* [Projects and build systems](../../build/projects-and-build-systems-cpp.md)
+* [Source files and source programs](../../c-language/source-files-and-source-programs.md)