How to Restrict Dynamic Allocation of Objects in C++?
C++ programming language allows both auto(or stack-allocated) and dynamically allocated objects. In Java & C#, all objects must be dynamically allocated using new.
C++ supports stack-allocated objects for the reason of runtime efficiency. Stack-based objects are implicitly managed by the C++ compiler. They are destroyed when they go out of scope and dynamically allocated objects must be manually released, using the delete operator otherwise, a memory leak occurs. C++ doesn’t support the automatic garbage collection approach used by languages such as Java & C#.
How do we achieve the following behavior from a class ‘Test’ in C++?
Test* t = new Test; // should produce compile time error Test t; // OK
The idea is to keep the new operator function private so that new cannot be called. See the following program. Objects of the ‘Test’ class cannot be created using new as new operator function is private in ‘Test’. If we uncomment the 2nd line of main(), the program would produce a compile-time error.
Constructor is called x = 9 Destructor is executed
Also, it is a general query if we can allocate memory for the objects dynamically in C++?
Yes, we can dynamically allocate objects also.
- Whenever a new object is created, constructor, a member function of a class is called.
- Whenever the object goes out of scope, destructor, a class member function is called.
Time complexity : O(1)
Auxiliary Space : O(1)
This article is contributed by Pravasi Meet. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.