Using a delegate stored as a member of a destroyed struct?

[Nicolas Sicard]

Running a piece of code that can be reduced to:

---
import std.stdio;
void main()
{
        import std.range;
        foreach(item; iota(0, 10).transform(2))
                writeln(item);
}

auto transform(T)(T list, real x)
{
        auto t = /* new */ Transformer(x);   // line 12
        return t.applyTo(list);
}

struct Transformer
{
        real delegate(real) fun;

        this(real x)
        {
                fun = (real r) => r * x;
        }

        auto applyTo(T)(T list)
        {
                import std.algorithm;
                return list.map!(x => fun(x));
        }
}
---

the program segfaults. I guess it's because fun is destroyed when 
't' goes out of scope in 'transform'. I would have thought that 
the MapResult struct returned by 'applyTo' still holds a valid 
copy of fun, but I'm wrong... Is there a way to do it?

Of course, uncommenting 'new' on line 12 resolves the problem.

Thanks,
Nicolas