func assert(_:_:file:line:)(_ condition: @autoclosure () -> Bool, _ message: @autoclosure () -> String = String(), file: StaticString = #file, line: UInt = #line)

Performs a traditional C-style assert with an optional message.

Use this function for internal sanity checks that are active during testing but do not impact performance of shipping code. To check for invalid usage in Release builds, see precondition(_:_:file:line:).