FunctionSwift
assertionFailure(_:file:line:)
Indicates that an internal sanity check failed.
func assertionFailure(_ message: @autoclosure () -> String = String(), file: StaticString = #file, line: UInt = #line)
Parameters
- message
A string to print in a playground or
-Onone
build. The default is an empty string.- file
The file name to print with
message
. The default is the file whereassertionFailure(_:file:line:)
is called.- line
The line number to print along with
message
. The default is the line number whereassertionFailure(_:file:line:)
is called.
Overview
This function’s effect varies depending on the build flag used:
In playgrounds and
-Onone
builds (the default for Xcode’s Debug configuration), stop program execution in a debuggable state after printingmessage
.In
-O
builds, has no effect.In
-Ounchecked
builds, the optimizer may assume that this function is never called. Failure to satisfy that assumption is a serious programming error.