C++ : What is smart pointer and how does it work ?

Question

I know the definition of singleton class i.e. a class for which only one object can be defined or initialized. But I want to know all the possible ways to achieve this restriction.

Answer 1

Smart pointer (as opposed to a "dumb" or "raw" pointer) is a C++ structure that behaves almost identically to a common C pointer but it also includes some other capabilities, e.g. throws an exception when it's NULL and someone tries to dereference it, or it destroys its contents automatically when it goes out of scope.

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