|This bothered me a little at first too but then it was pointed out that it's not too different than standard C++ pass-by-reference.
int x = 5;
Without examining the declaration of DoSomething() there's no indication at the calling site whether it's pass by value or by reference. The usual hidden C++ magic. Of course, intellisense helps some unless you're using C++/CLI...oh wait we are I use Visual Assist which helps sometimes.