海湾合作委员会Ubuntu 22.04 上的错误

Question

static unordered_map<string,RoadType> const road_type_string_map = {
  { "unclassified", RoadType::unclassified },
  { "service", RoadType::service },
  { "residential", RoadType::residential },
  { "tertiary", RoadType::tertiary },
  { "secondary", RoadType::secondary },
  { "primary", RoadType:primary }
};

上述代码在 Ubuntu 上编译20.04，但在22.04我收到错误：

sim.h:276:1: error: could not convert ‘{{"unclassified", unclassified}, {"service", service}, {"residential", residential}, {"tertiary", tertiary}, {"secondary", secondary}, {"primary", primary}}’ from ‘<brace-enclosed initializer list>’ to ‘const std::unordered_map<std::__cxx11::basic_string<char>, RoadType>’
  276 | };

makefile 使用“g++ -std=c++17 -Wall -g”