c++ error: expected primary-expression before '&' token
<p>I'm learning c++ and I have the following code which gives an error in line 39 (fill_file() call).  I've searched on the web for a solution but can't find why I get this error (expected primary-expression before '&amp;' token).</p>

<pre><code>#include &lt;iostream&gt;
#include &lt;string&gt;
#include &lt;vector&gt;
#include "../std_lib_facilities.h"
using namespace std;

struct Point {
    double x;
    double y;
};

void fill_file(vector&lt;Point&gt;&amp; original_points) {
    string outputfile="mydata.txt";
    ofstream ost{outputfile};
    if(!ost) error("Can't open outputfile ", outputfile);
    for(int i=0;i&lt;original_points.size();i++) {
        ost &lt;&lt; original_points[i].x &lt;&lt; " " &lt;&lt; original_points[i].y &lt;&lt; endl;
    }
}

int main() {
    cout &lt;&lt; "Please enter 3 points with a value: " &lt;&lt; endl;
    vector&lt;Point&gt; original_points;
    Point p;
    double x;
    double y;
    for(int i=0;i&lt;3;i++) {
        cin&gt;&gt;p.x;
        cin&gt;&gt;p.y;
        original_points.push_back(p);
    }
    cout &lt;&lt; endl;
    cout &lt;&lt; endl &lt;&lt; "Points: " &lt;&lt; endl;
    for(int i=0;i&lt;original_points.size();i++) {
        cout &lt;&lt; original_points[i].x &lt;&lt; " " &lt;&lt; original_points[i].y &lt;&lt; endl;
        /* ost &lt;&lt; original_points[i].x &lt;&lt; " " &lt;&lt; original_points[i].y &lt;&lt; endl; */
    }
    cout &lt;&lt; endl &lt;&lt; endl;
    fill_file(vector&lt;Point&gt;&amp; original_points);
    return 0;
}
</code></pre>

<p>What am I doing wrong?  Thx for the help!!</p>