[iter] fix forward implementation in hb_concat().
Add test coverage for forward.
diff --git a/src/test-iter.cc b/src/test-iter.cc
index ccc9118..6182eb1 100644
--- a/src/test-iter.cc
+++ b/src/test-iter.cc
@@ -132,8 +132,11 @@
hb_vector_t<int> d = {1, 2, 3, 4, 5};
auto it1 = hb_concat (a, b);
+ assert (it1.len () == 5);
auto it2 = hb_concat (c, d);
+ assert (it2.len () == 5);
auto it3 = hb_concat (d, c);
+ assert (it3.len () == 5);
for (int i = 0; i < 5; i++) {
assert(it1[i] == i + 1);
assert(it2[i] == i + 1);
@@ -143,6 +146,25 @@
check_sequential (it1);
check_sequential (it2);
check_sequential (it3);
+
+ auto it4 = +it1;
+ it4 += 2;
+ assert (*it4 == 3);
+ assert (it4);
+ assert (it4.len () == 3);
+
+ it4 += 2;
+ assert (*it4 == 5);
+ assert (it4);
+ assert (it4.len () == 1);
+
+ it4++;
+ assert (!it4);
+ assert (it4.len () == 0);
+
+ auto it5 = +it1;
+ it5 += 3;
+ assert (*it5 == 4);
}
int
