make maybe_iterator constructor private

thestinger · Jan 5, 2013 · 62faf9e · 62faf9e
1 parent 396f9ff
commit 62faf9e
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/maybe.hh b/maybe.hh
@@ -7,13 +7,13 @@
 #include <type_traits>
 #include <utility>
 
+template<typename T> struct maybe;
+
 template<typename T>
 struct maybe_iterator {
   typedef typename std::remove_pointer<T>::type value_type;
   typedef T pointer;
 
-  constexpr maybe_iterator(T p) noexcept : ptr(p) {}
-
   typename std::enable_if<!std::is_const<value_type>::value, value_type>::type
   &operator*() noexcept { return *ptr; }
 
@@ -39,7 +39,9 @@ struct maybe_iterator {
   }
 
 private:
+  constexpr maybe_iterator(T p) noexcept : ptr(p) {}
   T ptr;
+  friend maybe<value_type>;
 };
 
 template<typename T>