40   size_t pos = 0;  in format_string()  local
41   while (pos < str->size()) {  in format_string()
42     pos = str->find("$", pos);  in format_string()
43     if (pos == std::string::npos) break;  in format_string()
47       if (str->substr(pos + 1, token.size()) == token) {  in format_string()
48         str->replace(pos, token.size() + 1, replacement);  in format_string()
50         pos += replacement.size() - 1;  in format_string()
52       } else if (str->substr(pos + 1, token.size() + 2) == "{" + token + "}") {  in format_string()
53         str->replace(pos, token.size() + 3, replacement);  in format_string()
54         pos += replacement.size() - 1;  in format_string()
59     ++pos;  in format_string()