//! Applies string replacements starting from the specified position
result_type operator() (string_type& str, typename string_type::size_type start_pos = 0) const
{
base_type::operator() (str, start_pos);
typedef typename string_type::iterator string_iterator;
for (string_iterator it = str.begin() + start_pos, end = str.end(); it != end; ++it)
{
char_type c = *it;
if (c < 0x20 || c > 0x7e)
{
char_type buf[(std::numeric_limits< char_type >::digits + 3) / 4 + 3];
std::size_t n = traits_type::print_escaped(buf, c);
std::size_t pos = it - str.begin();
str.replace(pos, 1, buf, n);
it = str.begin() + n - 1;
end = str.end();
}
}
}
