Why if I use reference I don't need to deference a vector before using operator [] on it?

Question

If I pass a vector by reference to a function:

void QuadraticInterpolateArray(vector<double> &b) {
    double step = 12.2;
    for (int j = 0; j < b.size(); j++) {
        b[j] = step;
    }
}

I don't need later to deference b when I need to access to its value by using operator []. Instead, if I pass vector by pointer:

void QuadraticInterpolateArray(vector<double> *b)

I need (*b)[j] later.

In both case I'm passing the "address" of that vector. Why with reference it works and with pointer doesn't? Its just by design?

You never "dereference" references. You only dereference pointers. — Cody Gray - on strike, Jul 05 '16 at 13:47
See also [*what is a reference variable in C++?*](http://stackoverflow.com/questions/2765999/what-is-a-reference-variable-in-c) — juanchopanza, Jul 05 '16 at 13:48

score 1 · Accepted Answer · answered Jul 05 '16 at 13:47

1

Because references are automatically dereferenced by the compiler.

This was introduced by C++ to simplify C's pointers.

And yes, this is a design choice.

answered Jul 05 '16 at 13:47

Mattia F.

References were introduced in order to accommodate operator overloading. – Benjamin Lindley Jul 05 '16 at 14:31
Yes, it would be hard with pointers. – Mattia F. Jul 05 '16 at 14:33

1 Answers1