Question

1)The C++11 standard library provides access to a unique_ptr type. How does this object behave differently than a shared_ptr object? When would one use one over the other?

Answer 1

Pointers in C++

• So, when we talk about unique_ptr & shared_ptr they both act as the smart pointers which actually means that they will automatically deallocate the objects that they are being pointed at when the use of the object is no longer being referenced anywhere in the code.
• The main difference between both of the pointers lies in how many of the different types of pointers used in each type that can be referenced to the resource. When making use of the unique_ptr there must be at most one unique_ptr which will be pointing at the one resource.
• When this unique_ptr is being destroyed the resource will be automatically reclaimed. We cannot make a copy of the unique_ptr as any of the attempt to do this kind of thing will lead to the compile-time error.
• On the other hand, the shared_ptr will allow many or multiple pointers for pointing at a given resource. The resources will only get deallocated from the memory if the last of the shared_ptr is being deleted or destroyed.
• We must only use the unique_ptr when we want a single pointer for a particular object that can be easily reclaimed when the single pointer is being destroyed. But, when talking about the shared_ptr we can make use of it when we require multiple pointers for the same resources.

Hence, these are the times when one must make use of the unique_ptr and shared_ptr to make them work effectively in the program.