Method operator()

externals/picojson/picojson.h:531–556

template <typename Iter> struct serialize_str_char {
  Iter oi;
  void operator()(char c) {
    switch (c) {
#define MAP(val, sym)                                                                                                              \
  case val:                                                                                                                        \
    copy(sym, oi);                                                                                                                 \
    break
      MAP('"', "\\\"");
      MAP('\\', "\\\\");
      MAP('/', "\\/");
      MAP('\b', "\\b");
      MAP('\f', "\\f");
      MAP('\n', "\\n");
      MAP('\r', "\\r");
      MAP('\t', "\\t");
#undef MAP
    default:
      if (static_cast<unsigned char>(c) < 0x20 || c == 0x7f) {
        char buf[7];
        SNPRINTF(buf, sizeof(buf), "\\u%04x", c & 0xff);
        copy(buf, buf + 6, oi);
      } else {
        *oi++ = c;
      }
      break;
    }
  }
};

template <typename Iter> void serialize_str(const std::string &s, Iter oi) {