Fixing dispatch_async error in Swift 3/4

If you are copying some older Swift code (say circa 2014/15 or older) off the web to ensure some code is executed on the main queue, such as like this:

dispatch_async(dispatch_get_main_queue(), {
//do something that must be done on the main queue
})

You will be greeted with these 2 errors by Xcode:

‘dispatch_async’ has been replaced by instance method ‘DispatchQueue.async(execute:)’
‘dispatch_get_main_queue()’ has been replaced by property ‘DispatchQueue.main’

And unfortunately Xcode doesn’t offer to “fix” this for you automatically as it often does with other method calls that have been deprecated.

The new way to perform such a call is simply this:

DispatchQueue.main.async {
//do something that must be done on the main queue
}

 

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