fix Issue 9017 - __traits(compiles, { enum e = <expression tuple>; })…

… is true but code doesn't compile

src/cast.c

@@ -1566,6 +1566,9 @@ Expression *AddrExp::castTo(Scope *sc, Type *t)
 
 Expression *TupleExp::castTo(Scope *sc, Type *t)
 {
+    if (type->equals(t))
+        return this;
+
     TupleExp *e = (TupleExp *)copy();
     e->e0 = e0 ? e0->copy() : NULL;
     e->exps = (Expressions *)exps->copy();

src/declaration.c

@@ -1126,6 +1126,7 @@ void VarDeclaration::semantic(Scope *sc)
             }
 
             VarDeclaration *v = new VarDeclaration(loc, arg->type, id, ti);
+            v->storage_class |= storage_class;
             if (arg->storageClass & STCparameter)
                 v->storage_class |= arg->storageClass;
             //printf("declaring field %s of type %s\n", v->toChars(), v->type->toChars());

test/runnable/variadic.d

@@ -1514,6 +1514,34 @@ void test7263()
     auto spam2 = bars.front7263[1..2];
 }
 
+/***************************************/
+// 9017
+
+template X9017(Args...)
+{
+    static if(__traits(compiles, { enum e = Args; }))
+        enum e = Args;
+}
+alias X9017!0 x9017;
+static assert(x9017.e[0] == 0);
+
+void test9017()
+{
+    enum tup1 = TypeTuple!(11, 22);
+    enum tup2 = TypeTuple!("one", "two");
+    static assert(tup1 == TypeTuple!(11, 22));
+    static assert(tup2 == TypeTuple!("one", "two"));
+    static assert(tup1[0] == 11 && tup1[1] == 22);
+    static assert(tup2[0] == "one" && tup2[1] == "two");
+
+    shared const tup3 = TypeTuple!(10, 3.14);
+    immutable    tup4 = TypeTuple!("a", [1,2]);
+    static assert(is(typeof(tup3[0]) == shared const int));
+    static assert(is(typeof(tup3[1]) == shared const double));
+    static assert(is(typeof(tup4[0]) == immutable string));
+    static assert(is(typeof(tup4[1]) == immutable int[]));
+}
+
 /***************************************/
 // 10279
 
@@ -1612,6 +1640,7 @@ int main()
     test6530();
     test7233();
     test7263();
+    test9017();
     test10414();
 
     printf("Success\n");