How do you return a null reference in C++?

If you want a “reference” that might be null, the thing to do is to use a pointer rather than a reference. @DavidHammen: the standard says pretty much what I did above: that references point to an object. In doing so, the standard guarantees that references point to an object in valid well-defined C++ code.

Can C++ references be null?

References cannot be null, whereas pointers can; every reference refers to some object, although it may or may not be valid. Note that for this reason, containers of references are not allowed. References cannot be uninitialized.

How do you check for null references?

You can test for a null reference ( T& t = ; if (&t == 0) ) but it should not happen >> by contract a reference is valid.

How do you return a null object?

In Java, a null value can be assigned to an object reference of any type to indicate that it points to nothing. The compiler assigns null to any uninitialized static and instance members of reference type. In the absence of a constructor, the getArticles() and getName() methods will return a null reference.

Can we assign null to reference?

[Note: in particular, a null reference cannot exist in a well-defined program, because the only way to create such a reference would be to bind it to the “object” obtained by dereferencing a null pointer, which causes undefined behavior.

Can reference be set to null?

A reference shall be initialized to refer to a valid object or function. [Note: in particular, a null reference cannot exist in a well-defined program, because the only way to create such a reference would be to bind it to the “object” obtained by dereferencing a null pointer, which causes undefined behavior.

IS null a special C++ constant?

A null pointer constant can be converted to any pointer type (or pointer-to-member type), which acquires a null pointer value. This is a special value that indicates that the pointer is not pointing to any object.

Why can a reference never refer to null?

By default, Asan works by checking reads. Your code never actually reads from nullptr , so Asan doesn’t catch it. The reference itself is non-null, as it refers to a valid void* object, but the void* object itself is a null pointer. This is a case of “Reference to a null pointer.”