Unexpected foreach lowering

[Lodovico Giaretta via Digitalmars-d-learn]

I'm probably missing something stupid but...
Why on earth do the two loops in main print a different result?
It looks like the foreach lowering is ignoring my definition of 
front...

=====================================================
import std.stdio, std.container.array;

struct RangeWrapper(Range)
{
        Range range;
        alias range this;
        
        auto front()
        {
                return range.front + 1;
        }
}
auto rangeWrapper(Range)(auto ref Range range)
{
        return RangeWrapper!Range(range);
}

void main()
{
        Array!int array;
        array.insertBack(3);
        
        foreach (i; rangeWrapper(array[]))
                writeln(i);           // prints 3, which is wrong
        
        // isn't the above foreach equivalent to the following 
loop ?

        for (auto r = rangeWrapper(array[]); !r.empty; r.popFront())
                writeln(r.front);     // correctly prints 4
}
=====================================================

Thank you for your help.