typedef枚举输入 [英] typedef enum input

问题描述

如果我们在c ++中有这个：

  typedef enum {Unknown，USA，Canada，France，England，Italy，Spain ，Australia，} origin_t; 
 
 origin_t国家; 
 char * current; 
 cin>> current; 
  

如何设置 Country c-String 当前由用户输入？
除了比较一个接一个，因为我们有一个大的列表？
最快的方式？ $ C ++中的<$ c>和 string 或 char * 。

一个有效的方法是有一张地图：

  #include< map& 
 #include< string> 
 
 typedef enum {unknown，USA，Canada，France，England，Italy，Spain，Australia，} origin_t; 
 
 std :: map< std :: string，origin_t>国家; 
个国家/地区[未知] =未知; 
 countries [USA] =美国; 
 // ... 
 
 origin_t国家; 
 std :: string current; 
 cin>> current; 
国家= countries [当前]; 
  

请注意，在我的示例中，我使用 std :: string 而不是 char * ，这是你应该做的，除非你有强烈的理由使用 char * 。

if we have this in c++:

typedef enum {Unknown,USA,Canada,France,England,Italy,Spain,Australia,} origin_t;

origin_t Country;
char *current;
cin>>current;

how can we set Country to be the c-String current inputed by the user? other than comparing one by one since we have a large list? fastest way? thank you very much.

解决方案

There's no direct conversion between enum and string or char* in C++ as there is in Java.

An efficient way is to have a map:

#include <map>
#include <string>

typedef enum {Unknown,USA,Canada,France,England,Italy,Spain,Australia,} origin_t;

std::map<std::string, origin_t> countries;
countries["Unknown"] = Unknown;
countries["USA"] = USA;
//...

origin_t Country;
std::string current;
cin>>current;
Country = countries[current];

Note that in my sample I'm using std::string instead of char*, which is what you should do unless you have strong reasons to use char*.

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