string types: const(char)[] and cstring

[Walter Bright]

Reiner Pope wrote:
> Also, I can't see any difference between const(char) and 
> invariant(char), since neither can ever be rebound. In that case, if I 
> assume that they are identical types, how can an array of const(char) be 
> different from an array of invariant(char)?

The difference is when they are reference types, such as arrays of const 
char, or arrays of invariant chars.