diff --git a/doc/system/reference.adoc b/doc/system/reference.adoc
index ae4798c..a35989e 100644
--- a/doc/system/reference.adoc
+++ b/doc/system/reference.adoc
@@ -1600,6 +1600,12 @@ template<class T, class E = error_code> class result
 {
 public:
 
+    using value_type = T;
+    using error_type = E;
+
+    static constexpr in_place_value_t in_place_value{};
+    static constexpr in_place_error_t in_place_error{};
+
     // constructors
 
     constexpr result();
@@ -1916,6 +1922,12 @@ template<class E> class result<void, E>
 {
 public:
 
+    using value_type = void;
+    using error_type = E;
+
+    static constexpr in_place_value_t in_place_value{};
+    static constexpr in_place_error_t in_place_error{};
+
     // constructors
 
     constexpr result() noexcept;