public enum FeaturePrecondition: Hashable {
    case something
}

public enum SystemPermission: Hashable {
    case camera
}

public struct FeatureConstraints  {
    let preconditions: Set<FeaturePrecondition>
    let permissions: Set<SystemPermission>
    let isEmpty: Bool
    
    public init(preconditions: Set<FeaturePrecondition>, permissions: Set<SystemPermission>) {
        self.preconditions = preconditions
        self.permissions = permissions
        // This works...
        isEmpty = preconditions.isEmpty && permissions.isEmpty
    }

    public init(_ preconditions: Set<FeaturePrecondition>) {
        self.preconditions = preconditions
        permissions = []
        // This has compiler error "Constant 'self.isEmpty' captured by a closure before being initialized
        isEmpty = preconditions.isEmpty && permissions.isEmpty
        // This works however...
        // isEmpty = permissions.isEmpty
        // This also works...
        // isEmpty = preconditions.isEmpty
    }
}