OSLog extension for os_signpost usage

OSLog+Extensions.swift

/* Usage

let log = OSLog(subsystem: "deep-secrets", category: "cookie-recipes")
let signpostID = log.beginSignpost(withName: "signpost name")

... Do work ...

log.endSignpost(withName: "signpost name" , signpostId: signpostId)

Signposts can also be started w objects instead of SignpostIDs when scope is an issue

OSLog(subsystem: "deep-secrets", category: "cookie-recipes").beginSignpost(withName: "some name", object: obj)

... Do Work...

... somewhere else where same obj is in scope ...

let log = OSLog(subsystem: "subby", category: "fruit")
log.endSignpost(withName: "some name", signpostID: log.signpostID(withObject: obj))

*/

extension OSLog {
    
    @available(iOS 12.0, *)
    func beginSignpost(withName name:StaticString) -> OSSignpostID {
        let id = OSSignpostID(log: self)
        os_signpost(.begin, log: self, name:name, signpostID: id)
        return id
    }
    
    @available(iOS 12.0, *)
    func endSignpost(withName name:StaticString, signpostID:OSSignpostID) {
        os_signpost(.end, log: self, name: name, signpostID: signpostID)
    }
    
    @available(iOS 12.0, *)
    func beginSignpost(withName name:StaticString, object:AnyObject) {
        let id = OSSignpostID(log: self, object: object)
        os_signpost(.begin, log: self, name:name, signpostID: id)
    }
    
    @available(iOS 12.0, *)
    func signpostID() -> OSSignpostID {
        return OSSignpostID(log: self)
    }
    
    @available(iOS 12.0, *)
    func signpostID(withObject:AnyObject) -> OSSignpostID {
        return OSSignpostID(log: self, object: withObject)
    }
}