{

const char *position, *end;

StringIterator(const char * str) :

position(str),

end(str + strlen(str)) { }

bool at_end() const { return position == end; }

void advance() { ++position; }

char get_char() const { return *position; }

{

for(StringIterator i=iterator; !i.at_end(); i.advance())

{

std::cout << i.get_char();

}

{

StringIterator iterator("Hello world!\n");

hello_world(iterator);

return 0;