When you compile in unchecked mode, the compiler assumes that all preconditions are true and optimizes your code accordingly. This can improve the performance of your code, but it also means that preconditions will not be checked and your program may crash if a precondition is violated.
The `fatalError(_:file:line:)` function always halts execution, regardless of optimization settings. This makes it a good choice for creating stubs for functionality that hasn't been implemented yet. When you use `fatalError` as a stub, you can be sure that execution will always halt if the stub is called.
Here is an example of how you could use `fatalError` as a stub:
func doSomething() {
// This function hasn't been implemented yet.
fatalError("Unimplemented")
}
When you call `doSomething`, the program will crash with the following message:
Fatal error: Unimplemented
This will help you to identify and fix any errors in your code.
Here are some additional guidelines for using `fatalError`:
- Use `fatalError` only for errors that cannot be handled gracefully. For example, if a function expects a string parameter, you should use a guard statement to check for a nil value. If the string is nil, you can return an error instead of crashing the program.
- Use `fatalError` to document the expected behavior of your code. The message passed to `fatalError` should explain why the error is fatal. This can help other developers understand how to use your code correctly.
`fatalError` is a powerful tool that can help you write more reliable code. By using `fatalError` effectively, you can help to ensure that your code is robust and can handle unexpected input.
