How to loop through characters of a string in D language?

[Ola Fosheim Grøstad]

Of course, since it is easy to mess up and use ranges in the 
wrong way, you might want to add ```assert```s. That is most 
likely *helpful* to newbies that might want to use your kickass 
library function:

```
auto helpfuldeatheater(char stripchar)(string str) {
	struct voldemort {
         immutable(char)* begin, end;
         bool empty(){ return begin == end; }
         char front(){ assert(!empty); return *begin; }
         char back()@trusted{ assert(!empty); return *(end-1); }
         void popFront()@trusted{
			assert(!empty);
     		while(begin != end){begin++; if (*begin != stripchar) 
break; }
         }
         void popBack()@trusted{
             assert(!empty);
             while(begin != end){end--; if (*(end-1) != stripchar) 
break; }
         }
         this(string s)@trusted{
             begin = s.ptr;
             end = s.ptr + s.length;
             while(begin!=end && *begin==stripchar) begin++;
             while(begin!=end && *(end-1)==stripchar) end--;
         }
	}
     return voldemort(str);
}
```