text: #include <iostream>
  #include <unordered_map>
  
  int main(void) {
  
  	// that must compile with `--std=c++11`
  	/*
  	std::unordered_map<std::string, std::string> countries = {
  		{"USA", "United States Of America"},
  		{"PRC", "People's Republic of China"}
  	};
  	*/
  
  	std::unordered_map<std::string, std::string> countries = std::unordered_map<std::string, std::string>();
  	countries["USA"] = "United States Of America";
  	countries["PRC"] = "People's Republic of China";
  	countries["UK"] = "United Kingdoms";
  	
  	std::cout << "PRC is: " << countries["PRC"] << std::endl;
  	return 0;
  }