How to check if an enum variable is valid?

Question

I have an enum:

enum myenum{
  typeA,
  typeB,
  typeC
} myenum_t;

Then, a functions is to be called with an enum parameter:

Answer 1

Enumerations in C++ already have stronger types than in C.

Take the following simple program:

#include 

enum E
{
    A,
    B 
};

void f(E e)
{
}

int main()
{
    f(1);
}

Using the GCC compiler I will get a this error:

enum.cpp: In function ‘int main()’:
enum.cpp:15: error: invalid conversion from ‘int’ to ‘E’
enum.cpp:15: error:   initializing argument 1 of ‘void f(E)’

So as you can see the enumeration members are already checked.

If you want even stronger type checking, and have a C++11 capable compiler, you can use even stronger type checking for enums, see http://en.wikipedia.org/wiki/C%2B%2B11#Strongly_typed_enumerations.