error when declaring an enum to a variable

I have the following syntax:

enum home
{
no,
yes,
}homew;

home homes;

std::string s;
开发者_C百科s="no";

homes=s; //is not working. Why?

Were am I wrong?

You are confusing strings with enumerated values.

An enum variable is simply an integer that you can use a literal for at compile time, nothing more than that.

It makes the code more understandable and self-documenting rather than merely using a number literal.

1. This

   enum home { no, yes, } homew;
   

   defines the type home plus a variable homew of that type.
   Did you intent that? Why?

2. The values defined for an enum type are literals, to be used as such:

   home homes = no;
   

3. In C++ there's no built-in way to convert between enum value literals and a string representation of them. If you need this, you'll have to cook up your own.

enums in C++ are implicitly an int data type. You can't assign string values to enum.

It doesn't compile because C++ provides no built-in mechanism for converting from std::string to an enum.

typeof(home) != typeof(std::string) // types are not equal

Thus, you cannot assign an enum to std::string or otherwise. Implicit conversion between enum and integral types like bool, int etc. is possible however.

Is there a way I can solve my problem as it is?

If possible use std::map.

std::map<std::string, home> myTypes;
myTypes["yes"] = yes;
myTypes["no"] = no;

Now you can do,

homes = myTypes["no"];

As others pointed out, enums values are of int type. You could instead write a small function that converts from enum to String like this:

std::string GetStringFromEnum(home iHome)
{
 switch (home)
 {
  case yes: return "yes";
  case no: return "no"; break;
  default: return "here be dragons";
 }
}

and vice-versa:

home GetEnumFromString(std::string iImput)
{
 if (iImput == "yes") return yes;
 return no; //if you extend the enum beyond 2 values, this function will get more complicated
}

and you could modify your code like so:

homes = GetStringFromEnum(no)

the downside for this approach is that if you modify the enum, you must also modify the convert function.

HTH,
JP