Remove println() for release version iOS Swift

Question

I would like to globally ignore all println() calls in my Swift code if I am not in a Debug build. I can\'t find any robust step by step instructions for this a

Answer 1

Here is a function that I use, which works perfectly in Swift 3:

func gLog( _ object: @autoclosure() -> T, _ file: String = #file, _ function: String = #function, _ line: Int = #line)
    {
    #if DEBUG
        let value = object()
        let stringRepresentation: String

        if let value = value as? CustomDebugStringConvertible
            {
            stringRepresentation = value.debugDescription
            }
        else if let value = value as? CustomStringConvertible
            {
            stringRepresentation = value.description
            }
        else
            {
            fatalError("gLog only works for values that conform to CustomDebugStringConvertible or CustomStringConvertible")
            }

        let fileURL = NSURL(string: file)?.lastPathComponent ?? "Unknown file"
        let queue = Thread.isMainThread ? "UI" : "BG"
    let gFormatter = DateFormatter()
    gFormatter.dateFormat = "HH:mm:ss:SSS"
        let timestamp = gFormatter.string(from: Date())

        print("✅ \(timestamp) {\(queue)} \(fileURL) > \(function)[\(line)]: " + stringRepresentation + "\n")
    #endif
    }

Here is an example of the output it generates:

Explanation:

• the green checkmark is used to enable you to quickly see your print (gLog) messages in the console, where they can sometimes get lost in a sea of other messages

• the time/date stamp

• the thread it is being run on -- in my case it is either the MainThread (which I call UI), or not the MainThread (which I call BG, for background thread)

• the name of the file that the gLog message resides in

• the function within the file that the gLog message resides in

• the line number of the gLog message

• the actual gLog message you would like to print out

Hope this is useful to someone else!