Another prayer for invariant strngs

[Christian Kamm]

> So does this mean I don't need to be
> making defensive copies of every string?

Yep, dynamic arrays behave very much like pointers or classes:

void foo(const(char)[] str)
{
  // valid since str is not final
  // only changes local copy of array pointer and length
  str = "abc"; 

  // illegal! can't change the data of the array
  str[] = "abc";
}