How does C++ manage to avoid using the heap?

C++ does not avoid using the heap entirely, but it provides features that allow developers to manage memory more efficiently and avoid unnecessary heap allocations.

C++ provides automatic storage duration for variables declared within functions, which means that they are allocated on the stack and are automatically deallocated when the function returns. This allows for fast memory allocation and deallocation without the overhead of managing the heap.

C++ also allows developers to create objects with static storage duration, which are allocated at compile-time and persist for the entire duration of the program. These objects are also managed without using the heap.

In addition, C++ provides a number of language features and libraries that allow developers to allocate and manage memory on the heap in a more controlled and efficient way. For example, the new and delete operators can be used to explicitly allocate and deallocate memory on the heap, and the Standard Template Library (STL) provides container classes like vector and map that handle memory allocation and deallocation for dynamically-sized data structures.

However, it is still possible to use the heap in C++ and it is sometimes necessary for certain types of applications or data structures. When using the heap, it is important to manage memory carefully to avoid memory leaks or other issues that can arise from incorrect memory management.