Compiler Error C3168

'type' : illegal underlying type for enum

The underlying type you specified for the enum type was not valid. The underlying type must be an integral C++ type or a corresponding CLR type.

The following sample generates C3168:

// C3168.cpp
// compile with: /clr /c
ref class G{};

enum class E : G { e };   // C3168
enum class F { f };   // OK