[vala] Allow using array element access as ref and out method arguments

[Jürg Billeter <juergbi src gnome org>]

commit b7a5be2f5a2b1d2c4ab03d6e74251f41c53ce893
Author: Jürg Billeter <j bitron ch>
Date:   Wed Feb 10 10:59:51 2010 +0100

    Allow using array element access as ref and out method arguments
    
    Fixes bug 609388.

 vala/valaunaryexpression.vala |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)
---
diff --git a/vala/valaunaryexpression.vala b/vala/valaunaryexpression.vala
index a171c8e..53ebd9a 100644
--- a/vala/valaunaryexpression.vala
+++ b/vala/valaunaryexpression.vala
@@ -215,13 +215,15 @@ public class Vala.UnaryExpression : Expression {
 			assignment.check (analyzer);
 			return true;
 		} else if (operator == UnaryOperator.REF || operator == UnaryOperator.OUT) {
-			if (inner.symbol_reference is Field || inner.symbol_reference is FormalParameter || inner.symbol_reference is LocalVariable) {
-				// ref and out can only be used with fields, parameters, and local variables
+			var ea = inner as ElementAccess;
+			if (inner.symbol_reference is Field || inner.symbol_reference is FormalParameter || inner.symbol_reference is LocalVariable ||
+			    (ea != null && ea.container.value_type is ArrayType)) {
+				// ref and out can only be used with fields, parameters, local variables, and array element access
 				lvalue = true;
 				value_type = inner.value_type;
 			} else {
 				error = true;
-				Report.error (source_reference, "ref and out method arguments can only be used with fields, parameters, and local variables");
+				Report.error (source_reference, "ref and out method arguments can only be used with fields, parameters, local variables, and array element access");
 				return false;
 			}
 		} else {