Function foreachpair

3rdparty/libprocess/src/http.cpp:1003–1009

  string output;

  foreachpair (const string& key, const string& value, query) {
    output += http::encode(key);
    if (!value.empty()) {
      output += "=" + http::encode(value);
    }
    output += '&';
  }
  return strings::remove(output, "&", strings::SUFFIX);
}