--- a/dmd/ArrayLengthExp.d	Sun Sep 05 15:32:22 2010 +0400
+++ b/dmd/ArrayLengthExp.d	Thu Sep 09 22:51:44 2010 +0100
@@ -2,6 +2,7 @@
 
 import dmd.common;
 import dmd.Expression;
+import dmd.BinExp;
 import dmd.backend.elem;
 import dmd.UnaExp;
 import dmd.InterState;
@@ -13,6 +14,16 @@
 import dmd.TOK;
 import dmd.Type;
 import dmd.WANT;
+import dmd.VarExp;
+import dmd.VarDeclaration;
+import dmd.PtrExp;
+import dmd.Lexer;
+import dmd.Identifier;
+import dmd.ExpInitializer;
+import dmd.DeclarationExp;
+import dmd.CommaExp;
+import dmd.AssignExp;
+import dmd.AddrExp;
 
 import dmd.expression.ArrayLength;
 
@@ -28,8 +39,6 @@
 
 	override Expression semantic(Scope sc)
 	{
-		Expression e;
-
 	version (LOGSEMANTIC) {
 		printf("ArrayLengthExp::semantic('%s')\n", toChars());
 	}
@@ -43,6 +52,35 @@
 		return this;
 	}
 
+	static Expression rewriteOpAssign(BinExp exp)
+	{
+		Expression e;
+
+		assert(exp.e1.op == TOKarraylength);
+		auto ale = cast(ArrayLengthExp)exp.e1;
+		if (ale.e1.op == TOK.TOKvar)
+		{
+		    e = opAssignToOp(exp.loc, exp.op, ale, exp.e2);
+		    e = new AssignExp(exp.loc, ale.syntaxCopy(), e);
+		}
+		else
+		{
+		    /*    auto tmp = &array;
+		     *    (*tmp).length = (*tmp).length op e2
+		     */
+		    Identifier id = Lexer.uniqueId("__arraylength");
+		    ExpInitializer ei = new ExpInitializer(ale.loc, new AddrExp(ale.loc, ale.e1));
+		    VarDeclaration tmp = new VarDeclaration(ale.loc, ale.e1.type.pointerTo(), id, ei);
+
+		    Expression e1 = new ArrayLengthExp(ale.loc, new PtrExp(ale.loc, new VarExp(ale.loc, tmp)));
+		    Expression elvalue = e1.syntaxCopy();
+		    e = opAssignToOp(exp.loc, exp.op, e1, exp.e2);
+		    e = new AssignExp(exp.loc, elvalue, e);
+		    e = new CommaExp(exp.loc, new DeclarationExp(ale.loc, tmp), e);
+		}
+		return e;
+	}
+    
 	override Expression optimize(int result)
 	{
 		//printf("ArrayLengthExp::optimize(result = %d) %s\n", result, toChars());