Christoffer Hammarström created SLF4J-485: --------------------------------------------- Summary: LoggingEventBuilder addArgument() should take Supplier<?>, not Supplier<Object> Key: SLF4J-485 URL: https://jira.qos.ch/browse/SLF4J-485 Project: SLF4J Issue Type: Bug Components: Core API Affects Versions: 2.0.0-alpha1 Reporter: Christoffer Hammarström Assignee: SLF4J developers list `addArgument(Supplier<Object>)` prevents passing in any `Supplier<? extends Object>`. Try the following JUnit 4 test: {noformat} import java.util.function.Supplier; import org.junit.Test; public class GenericsTest { @Test public void testObjectSupplier() { Supplier<Object> objectSupplier = () -> "Object"; Supplier<String> stringSupplier = () -> "String"; object(objectSupplier); //object(stringSupplier); // Uncommenting leads to compile failure //string(objectSupplier); // Uncommenting leads to compile failure string(stringSupplier); extendsObject(objectSupplier); // Works fine extendsObject(stringSupplier); // Works fine } private void object(Supplier<Object> objectSupplier) { System.out.println("object: "+objectSupplier.get()); } private void string(Supplier<String> stringSupplier) { System.out.println("string: "+stringSupplier.get()); } private void extendsObject(Supplier<?> extendsObjectSupplier) { System.out.println("extends object: "+extendsObjectSupplier.get()); } } {noformat} -- This message was sent by Atlassian JIRA (v7.3.1#73012)