Incompatible types Void and Object - Java Generics

Question

Below code throws

"Incompatible types. Required Sample<Void> but create was inferred to Sample<T>. Incompatible equality constraints:Void and Object".

public class SampleClass{
  public static <T> Sample<T> create(String str) {}
}

Sample<Void> sample = SampleClass.create("abc");

What's `Sample`? Please provide a [mcve], [cannot reproduce](https://ideone.com/T596o0). — Andy Turner, Apr 06 '20 at 16:02
Check this: https://stackoverflow.com/questions/3012781/java-syntax-for-explicitly-specifying-generic-arguments-in-method-calls/3012789 — Buddhima Gamlath, Apr 06 '20 at 16:05
Does this answer your question? [Java-syntax for explicitly specifying generic arguments in method calls](https://stackoverflow.com/questions/3012781/java-syntax-for-explicitly-specifying-generic-arguments-in-method-calls) — Buddhima Gamlath, Apr 06 '20 at 16:10
pls ignore this question.. it was something wrong on my side. Sorry — dj308, Apr 13 '20 at 22:37

score 0 · Answer 1 · answered Apr 11 '20 at 07:20

It actually does work.

Full example:

public class SampleClass {

    public static void main(String[] args) {
        Sample<Void> sample = SampleClass.create("abc");

    }

    public static <T> Sample<T> create(String str) {
        return null;
    }

    private static class Sample<T> {
    }
}

Compiles and executes just fine (with JDK 11).

Incompatible types Void and Object - Java Generics

1 Answers1