Non null pointer

Question

How to make std::exception_ptr as a non null pointer.
Std::exception_ptr qtr;

Answer 1

std::exception_ptr is a nullable pointer-like type that manages an exception object which has been thrown and captured with std::current_exception. An instance of std::exception_ptr may be passed to another function, possibly on another thread, where the exception may be rethrown and handled with a catch clause.

A default-constructed std::exception_ptr is a null pointer; it does not point to an exception object.

Two instances of std::exception_ptr compare equal only if they are both null or both point at the same exception object.

std::exception_ptr is not implicitly convertible to any arithmetic, enumeration, or pointer type. It is contextually convertible to bool, and will evaluate to false if it is null, true otherwise.

The exception object referenced by an std::exception_ptr remains valid as long as there remains at least one std::exception_ptr that is referencing it: std::exception_ptr is a shared-ownership smart pointer (note; this is in addition to the usual exception object lifetime rules)

std::exception_ptr meets the requirements of NullablePointer.

source: https://en.cppreference.com/w/cpp/error/exception_ptr