c# - Why enums require an explicit cast to int type?

Question

There is no data loss by doing this, so what's the reason for having to explicitly cast enums to ints?

Would it not be more intuitive if it was implicit, say when you have a higher level method like:

PerformOperation ( OperationType.Silent type )

where PerformOperation calls a wrapped C++ method that's exposed as such:

_unmanaged_perform_operation ( int operation_type )

Answer 1

There are two primary and inconsistent uses of enums:

enum Medals
{ Gold, Silver, Bronze }

[Flags]
enum FilePermissionFlags
{
    CanRead = 0x01,
    CanWrite = 0x02,
    CanDelete = 0x04
}

In the first case, it makes no sense to treat these things as numbers. The fact that they are stored as integers is an implementation detail. You can't logically add, subtract, multiply or divide Gold, Silver and Bronze.

In the second case, it also makes no sense to treat these things as numbers. You can't add, subtract, multiply or divide them. The only sensible operations are bitwise operations.

Enums are lousy numbers, so you should not be able to treat them as numbers accidentally.