Neatest way to 'OR' all values in a Flagged Enum?

Question

Given the enum:

[Flags]
public enum mytest
{
    a = 1,
    b = 2,
    c = 4
}

I\'ve come up with two ways to represent all va

Answer 1

If it makes sense to have an All member, just provide it directly:

[Flags]
public enum mytest
{
    a = 1,
    b = 2,
    c = 4,
    All = 7
}

Though, a more idiomatic way to write these could be:

[Flags]
public enum MyTest
{
    A = 1,
    B = 1 << 0x01,
    C = 1 << 0x02,
    All = A | B | C
}

This shows the logical progression of the enum values, and in the All case, makes it easy to add another member.