Fixed gcc error

src/typed-geometry/types/objects/line.hh

@@ -46,8 +46,8 @@ template <int D, class ScalarT>
 struct line
 {
     using scalar_t = ScalarT;
-    using dir_t = dir<D, ScalarT>;
-    using pos_t = pos<D, ScalarT>;
+    using dir_t = tg::dir<D, ScalarT>; // Note: gcc requires the tg:: prefix to distinguish from member variable
+    using pos_t = tg::pos<D, ScalarT>;
 
     pos_t pos;
     dir_t dir;

src/typed-geometry/types/objects/ray.hh

@@ -44,8 +44,8 @@ template <int D, class ScalarT>
 struct ray
 {
     using scalar_t = ScalarT;
-    using dir_t = dir<D, ScalarT>;
-    using pos_t = pos<D, ScalarT>;
+    using dir_t = tg::dir<D, ScalarT>; // Note: gcc requires the tg:: prefix to distinguish from member variable
+    using pos_t = tg::pos<D, ScalarT>;
 
     pos_t origin;
     dir_t dir;

src/typed-geometry/types/objects/segment.hh

@@ -44,6 +44,7 @@ using usegment4 = segment<4, u32>;
 template <int D, class ScalarT>
 struct segment
 {
+    using scalar_t = ScalarT;
     using pos_t = pos<D, ScalarT>;
 
     pos_t pos0;