Listing 1

typedef std::vector<std::string> word_array;
word_array strs;
// ... fill it
int words_len = 0;
// use 'for' syntax
for ( crange<word_array> r(strs); r; ++r) 
    words_len += r->length();
// use while syntax
int words_len = 0;
crange<word_array> r(strs):
while (r) {
    words_len += r->length();
    ++r;
}