How Do C References Impact Memory Allocation?

Understanding the Memory Implications of C References

In C , a reference is a variable that refers to another variable's address. When examining memory allocation, this raises questions about the space occupied by references compared to other data types.

Consider the code snippet:

int i = 42;
int& j = i;
int k = 44;

As expected, variables i and k each take up 4 bytes on the stack. However, j takes up no space in memory. This is because a reference does not itself store a value; it simply binds to the address of the variable it references, effectively acting as an alias.

So, where does a reference take up space when passed as a function argument?

When a reference is passed, the compiler assigns it a temporary location on the function's stack. This location stores the address of the variable being referenced, allowing the function to access it directly. In our example, when j is passed to a function, the function's stack holds the address of variable i.

Regarding arrays of references, the C Standard explicitly prohibits their creation:

int&[] arr = new int&[SIZE]; // compiler error! array of references is illegal

This is due to the risk of dangling references, which can point to deallocated memory. By disallowing array references, C ensures memory safety.

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