const exception_type &assume_exception() const & noexcept
Narrow contract const lvalue reference observer of the stored exception. NoValuePolicy::narrow_exception_check() is first invoked, then the reference to the exception is returned. As a valid default constructed exception is always present, no undefined behaviour occurs unless NoValuePolicy::narrow_exception_check() does that.
Note that if exception_type is void, only a const overload returning void is present.
Requires: Always available.
Complexity: Depends on NoValuePolicy::narrow_exception_check().
Guarantees: An exception is never thrown.



