1 files changed, 5 insertions, 1 deletions
diff --git a/fpga_interchange/arch.h b/fpga_interchange/arch.h
index 556aa566..1daf5526 100644
--- a/fpga_interchange/arch.h
+++ b/fpga_interchange/arch.h
@@ -656,7 +656,11 @@ struct BelPinRange
     BelPinIterator end() const { return e; }
 };
 
-struct IdStringIterator
+struct IdStringIterator : std::iterator<std::forward_iterator_tag,
+                                        /*T=*/IdString,
+                                        /*Distance=*/ptrdiff_t,
+                                        /*pointer=*/IdString *,
+                                        /*reference=*/IdString>
 {
     const int32_t *cursor;