Java @SafeVarargs annotation

In Java, the @SafeVarargs annotation is used to indicate that a method or constructor is safe to use with a variable number of arguments (varargs) that are annotated with a non-reifiable type.

A non-reifiable type is a type that cannot be stored in an array without an unchecked warning at runtime. Non-reifiable types include generic types and arrays of a type parameter.

Here is an example of how the @SafeVarargs annotation can be used:

import java.util.List;

public class MyClass {
    @SafeVarargs
    public static <T> void addAll(List<T> list, T... elements) {
        for (T element : elements) {
            list.add(element);
        }
    }
}

In this example, the addAll method takes a list and a variable number of elements and adds the elements to the list. The @SafeVarargs annotation indicates that it is safe to use the varargs parameter elements with a non-reifiable type.

It is important to note that the @SafeVarargs annotation is only applicable to methods and constructors and cannot be applied to fields or class definitions. Additionally, the @SafeVarargs annotation should only be used when it is indeed safe to use the varargs parameter with a non-reifiable type. Using the @SafeVarargs annotation improperly can result in runtime errors.