Question

Why does this declaration,

public enum ECountry : long
{
    None,
    Canada,
    UnitedStates
}

require a cast for any of its values?

long ID = ECountry.Canada;
// Error Cannot implicitly convert type 'ECountry' to 'long'.
// An explicit conversion exists (are you missing a cast?)

And is there a way to get a long value directly from the enum, besides casting?

This would not work either, for example:

public enum ECountry : long
{
    None = 0L,
    Canada = 1L,
    UnitedStates=2L
}

Answer 1

The issue is not that the underlying type is still int. It’s long, and you can assign long values to the members. However, you can never just assign an enum value to an integral type without a cast. This should work:

public enum ECountry : long
{
    None,
    Canada,
    UnitedStates = (long)int.MaxValue + 1;
}

// val will be equal to the *long* value int.MaxValue + 1
long val = (long)ECountry.UnitedStates;