From 4c8b0d2dee50a237761adf34ab19c406f6e4a84a Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Fri, 22 Feb 2019 02:07:47 +0200
Subject: [PATCH] Document reference specializations of variant_size,
 variant_alternative

---
 doc/variant/reference.adoc | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/doc/variant/reference.adoc b/doc/variant/reference.adoc
index eed8867..3f6a98f 100644
--- a/doc/variant/reference.adoc
+++ b/doc/variant/reference.adoc
@@ -41,6 +41,9 @@ template<class T> struct variant_size<T const>: variant_size<T> {};
 template<class T> struct variant_size<T volatile>: variant_size<T> {};
 template<class T> struct variant_size<T const volatile>: variant_size<T> {};
 
+template<class T> struct variant_size<T&>: variant_size<T> {}; // extension
+template<class T> struct variant_size<T&&>: variant_size<T> {}; // extension
+
 template<class T>
   inline constexpr size_t variant_size_v = variant_size<T>::value;
 
@@ -56,6 +59,9 @@ template<size_t I, class T> struct variant_alternative<I, T const>;
 template<size_t I, class T> struct variant_alternative<I, T volatile>;
 template<size_t I, class T> struct variant_alternative<I, T const volatile>;
 
+template<size_t I, class T> struct variant_alternative<I, T&>; // extension
+template<size_t I, class T> struct variant_alternative<I, T&&>; // extension
+
 template<size_t I, class T>
   using variant_alternative_t = typename variant_alternative<I, T>::type;
 
@@ -630,6 +636,12 @@ template<size_t I, class T> struct variant_alternative<I, T volatile>;
 ```
 template<size_t I, class T> struct variant_alternative<I, T const volatile>;
 ```
+```
+template<size_t I, class T> struct variant_alternative<I, T&>; // extension
+```
+```
+template<size_t I, class T> struct variant_alternative<I, T&&>; // extension
+```
 [none]
 * {blank}
 +
@@ -639,8 +651,10 @@ If `typename variant_alternative<I, T>::type` exists and is `U`,
 * `variant_alternative<I, T const>::type` is `U const`;
 * `variant_alternative<I, T volatile>::type` is `U volatile`;
 * `variant_alternative<I, T const volatile>::type` is `U const volatile`.
+* `variant_alternative<I, T&>::type` is `U&`.
+* `variant_alternative<I, T&&>::type` is `U&&`.
 
-Otherwise, the three structs have no `type` member.
+Otherwise, these structs have no member `type`.
 --
 
 ```
@@ -651,7 +665,7 @@ template<size_t I, class... T>
 * {blank}
 +
 When `I < sizeof...(T)`, the nested type `type` is an alias for the `I`-th
-(zero-based) type in `T...`. Otherwise, there is no `type` member.
+(zero-based) type in `T...`. Otherwise, there is no member `type`.
 
 ### holds_alternative