fix CTAD with deduction guide

microsoft · Apr 9, 2019 · cf2cd7b · cf2cd7b
1 parent 9bfa724
commit cf2cd7b
Showing 1 changed file with 6 additions and 7 deletions.
diff --git a/include/gsl/pointers b/include/gsl/pointers
@@ -71,18 +71,12 @@ class not_null
 public:
     static_assert(std::is_assignable<T&, std::nullptr_t>::value, "T cannot be assigned nullptr.");
 
-    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
+    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value && !std::is_same<std::nullptr_t, T>::value>>
     constexpr not_null(U&& u) : ptr_(std::forward<U>(u))
     {
         Expects(ptr_ != nullptr);
     }
 
-    template <typename = std::enable_if_t<!std::is_same<std::nullptr_t, T>::value>>
-    constexpr not_null(T u) : ptr_(u)
-    {
-        Expects(ptr_ != nullptr);
-    }
-
     template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
     constexpr not_null(const not_null<U>& other) : not_null(other.get())
     {
@@ -120,6 +114,11 @@ private:
     T ptr_;
 };
 
+#if defined(__cplusplus) && (__cplusplus >= 201703L)
+template<class T>
+not_null(T) -> not_null<T>;
+#endif // #if defined(__cplusplus) && (__cplusplus >= 201703L)
+
 template <class T>
 auto make_not_null(T&& t) {
     return not_null<std::remove_cv_t<std::remove_reference_t<T>>>{std::forward<T>(t)};