c ++指向引用的指针

Question

Is it legal to have a pointer of a reference in C++?

For example:

int &ref = array[idx];
func(&ref);

One reason I can think of why you might want to do this if func() already exists in a library which you can't change.

Answer 1

It is not. The address of a reference can be taken, but "pointer to a reference of T" is not a valid type. What you are doing here is taking a pointer to the object itself, since a reference to an object simply creates another name by which you can access that same object .

Answer 2

That code is legal, but it does not create a pointer to the reference. It creates a pointer to the referent (the reference target).

Answer 3

Pointer points to an object and reference is not an object to have pointer to it. Reference is just an alias .

This post on SO has information - Why pointers to a reference is illegal?

Answer 4

If by "have a pointer of a reference" you mean taking the address of a reference (as in your sample: &ref ), then it's perfectly legal. Any variable is an identifier, hence & can be applied by § 5.3.1-2 of C++-03. Expressions with reference types are lvalues, and thus & is applicable by the same section.

If by "have a pointer of a reference" you mean a type that's a pointer to a reference (eg int &* ), then no, by § 8.3.2-4 (and the note at § 8.3.1-4).