fix istream for optional

Co-authored-by: Laurent Rineau <[email protected]>
CGAL · Aug 18, 2023 · b2be6db · b2be6db
1 parent 5a962eb
commit b2be6db
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/Stream_support/include/CGAL/IO/io.h b/Stream_support/include/CGAL/IO/io.h
@@ -281,7 +281,11 @@ class Input_rep<std::optional<T>>
   Input_rep( std::optional<T>& tt) : t(tt) {}
 
   //! perform the input, calls \c operator\>\> by default.
-  std::istream& operator()( std::istream& is) const { return (is >> t.value()); }
+  std::istream& operator()( std::istream& is) const {
+    T v;
+    if(is >> v) t = v;
+    return is;
+  }
 };
 
 #if CGAL_FORCE_IFORMAT_DOUBLE || \