Where are references and pointers enforced?

Question

From what I understand, pointers hold the addresses of a value, and references can be thought as const pointers.

From this sample code:

int main() {
    int i = 1;
    int &ri = i;
    int *pi = &i;
    return 0;
}

The disassembly, both pointer and reference look exactly the same:

main:
    push    ebp
    mov ebp, esp
    sub esp, 16
    mov DWORD PTR [ebp-12], 1
    lea eax, [ebp-12]
    mov DWORD PTR [ebp-8], eax
    lea eax, [ebp-12]
    mov DWORD PTR [ebp-4], eax
    mov eax, 0
    leave
    ret

Are pointers and references only enforced by the compiler?

struggling to understand what you mean by "enforced" . They are language features and they are working as intended — M.M, Feb 23 '17 at 05:01
BTW inspecting unoptimized assembly is a poor way to learn , as you only really learn about one particular implementation's implementation details. You might overlook the fact that `int ri = 1; int &i = ri;` would have the same behaviour. — M.M, Feb 23 '17 at 05:02

R Sahu · Accepted Answer · 2017-02-23T05:28:19.267

From what I understand, pointers hold the addresses of a value, and references can be thought as const pointers.

That's a simplistic view. The standard defines their behavior. It's up to an implementation to figure out how to support that behavior.

Given

int i = 0;
int& ref = i;
int* ptr = &i;

the standard mandates that

&ref == &i

and

&ptr != &i;

Hence, it may make sense to think of references as const pointers for some aspects of its behavior but it definitely does not make sense for all aspects of its behavior.

Where are references and pointers enforced?

1 Answers1