What is a convenient way to work with OptionSet?

I work on a project with many bitwise option sets and each of them contains many options with all option e.g:

struct MyOption: OptionSet {
    let rawValue: Int
    
    static let a = Self(rawValue: 1 << 0)
    static let b = Self(rawValue: 1 << 1)
    static let c = Self(rawValue: 1 << 2)
    ...
    static let last = Self(rawValue: 1 << N)
    
    static let all: Self = [.a, .b, .c, ..., .last]
}

It requires to maintain much of similar code so is it any way to eliminate hardcoded bitwise shift operations and the all option?

You can use next OptionSet's extension which implements all option and a convenient initializer:

extension OptionSet where RawValue == Int {
    static var all: Self {
        Self.init(rawValue: Int.max)
    }
    
    init(_ shift: Int) {
        self.init(rawValue: 1 << shift)
    }
}

Then you can re-write your option set:

struct Option: OptionSet {
    let rawValue: Int
    
    static let a = Self(0)
    static let b = Self(1)
    static let c = Self(2)
}

Option.a.rawValue // 1
Option.b.rawValue // 2
Option.c.rawValue // 4

let options: Option = [.a, .b]
Option.all.contains(options) // true