```d
import std.variant;
// error: destructor `std.variant.VariantN!32LU.VariantN.~this`
is not `nothrow`
void fun(Variant v) nothrow
{
}
void main()
{
fun(Variant());
}
```
A reference, pointer or slice works. I could do something on the
caller site but the signature of `fun()` should remain like above.