Bug 144879

Summary:	[1.5][compiler] Assignment using inferred type should be rejected
Product:	[Eclipse Project] JDT	Reporter:	Philipe Mulet <philippe_mulet>
Component:	Core	Assignee:	JDT-Core-Inbox <jdt-core-inbox>
Status:	RESOLVED INVALID	QA Contact:
Severity:	normal
Priority:	P3	CC:	nbeyer
Version:	3.2
Target Milestone:	3.2.1
Hardware:	PC
OS:	Windows XP
Whiteboard:

Description Philipe Mulet

2006-06-01 09:23:48 EDT

Build 3.2RC6

Based on: http://forum.java.sun.com/thread.jspa?threadID=741203&tstart=0

The assignment to "it2" should be rejected:
import java.util.*;

public class X {
  static final <T, E extends T> Iterator<T> chain(Iterator<E>... it) {
	return null;
  }
  void foo3() {
	List<Integer> l1 = Arrays.asList(1, 2, 3);
	Iterator<Number> it2 = X.chain(l1.iterator(), l1.iterator());
  }
}

Comment 1 Philipe Mulet

2006-06-01 09:38:49 EDT

Actually, I believe the code is valid.

Inference is performing in 2 passes.
1st pass is inferring from argument types, which is going to bind E to Integer.
Since T is still unbound, it will consider extra constraints:
1. expectation from return type as invocation is rhs of assignment:
   Iterator<T> <: Iterator<Number>
2. expectation from type parameter declared bounds
   T :> Integer

These should yield: T == Number, as this is the only one satisfying both constraints

Comment 2 Philipe Mulet

2006-06-01 09:44:18 EDT

Added GenericTypeTest#test0999&1000

Comment 3 Philipe Mulet

2006-06-06 04:08:24 EDT

*** Bug 145420 has been marked as a duplicate of this bug. ***