Rough edge of Java 10 type inference

Main.java

package test;

import java.util.List;
import java.util.ArrayList;
import java.io.Serializable;

public class Main {
	
	private static void trick(List list){
		// WARNING: black magic with non-generic code on a generic List…
		list.clear();
		list.add(new Serializable(){}); // Serializable but not CharSequence
		list.add(new javax.swing.text.Segment()); // CharSequence but not Serializable
	}
	
	public static void main(String[] args) {
		var list = new ArrayList<>(List.of("", new StringBuilder()));
		trick(list);
		for (int i=0; i<list.size(); i++){
			try {
				System.out.println("Looking at item #"+i);
				var item = list.get(i); // fails here with the second item (new javax.swing.text.Segment())
				System.out.println("Got the item.");
				System.out.println(item.charAt(0)); // fails here with the first item (new Serializable(){})
			} catch(Throwable e){
				e.printStackTrace();
				// continue experiment
			}
		}
	}
}

output-bytecode.txt

% javap -c test.Main
Compiled from "Main.java"
public class test.Main {
  public test.Main();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static void main(java.lang.String[]);
    Code:
       0: new           #8                  // class java/util/ArrayList
       3: dup
       4: ldc           #9                  // String
       6: new           #10                 // class java/lang/StringBuilder
       9: dup
      10: invokespecial #11                 // Method java/lang/StringBuilder."<init>":()V
      13: invokestatic  #12                 // InterfaceMethod java/util/List.of:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/util/List;
      16: invokespecial #13                 // Method java/util/ArrayList."<init>":(Ljava/util/Collection;)V
      19: astore_1
      20: aload_1
      21: invokestatic  #14                 // Method trick:(Ljava/util/List;)V
      24: iconst_0
      25: istore_2
      26: iload_2
      27: aload_1
      28: invokevirtual #15                 // Method java/util/ArrayList.size:()I
      31: if_icmpge     93
      34: getstatic     #16                 // Field java/lang/System.out:Ljava/io/PrintStream;
      37: iload_2
      38: invokedynamic #17,  0             // InvokeDynamic #0:makeConcatWithConstants:(I)Ljava/lang/String;
      43: invokevirtual #18                 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
      46: aload_1
      47: iload_2
      48: invokevirtual #19                 // Method java/util/ArrayList.get:(I)Ljava/lang/Object;
      51: checkcast     #20                 // class java/io/Serializable
      54: astore_3
      55: getstatic     #16                 // Field java/lang/System.out:Ljava/io/PrintStream;
      58: ldc           #21                 // String Got the item.
      60: invokevirtual #18                 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
      63: getstatic     #16                 // Field java/lang/System.out:Ljava/io/PrintStream;
      66: aload_3
      67: checkcast     #22                 // class java/lang/CharSequence
      70: iconst_0
      71: invokeinterface #23,  2           // InterfaceMethod java/lang/CharSequence.charAt:(I)C
      76: invokevirtual #24                 // Method java/io/PrintStream.println:(C)V
      79: goto          87
      82: astore_3
      83: aload_3
      84: invokevirtual #26                 // Method java/lang/Throwable.printStackTrace:()V
      87: iinc          2, 1
      90: goto          26
      93: return
    Exception table:
       from    to  target type
          34    79    82   Class java/lang/Throwable
}

output.txt

% java test/Main      
Looking at item #0
Got the item.
java.lang.ClassCastException: test.Main$1 cannot be cast to java.base/java.lang.CharSequence
	at test.Main.main(Main.java:24)
Looking at item #1
java.lang.ClassCastException: java.desktop/javax.swing.text.Segment cannot be cast to java.base/java.io.Serializable
	at test.Main.main(Main.java:22)