From 5c6303dbee3b75e07e3ba0f0885be57ea5d5a712 Mon Sep 17 00:00:00 2001
From: Anthony Calandra <anthony@anthony-calandra.com>
Date: Fri, 26 Jun 2020 22:16:53 -0400
Subject: [PATCH] Add lambda captures of parameter packs.

---
 CPP20.md  | 23 +++++++++++++++++++++++
 README.md | 23 +++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/CPP20.md b/CPP20.md
index a118e54..7567eee 100644
--- a/CPP20.md
+++ b/CPP20.md
@@ -15,6 +15,7 @@ C++20 includes the following new language features:
 - [explicit(bool)](#explicitbool)
 - [immediate functions](#immediate-functions)
 - [using enum](#using-enum)
+- [lambda capture of parameter pack](#lambda-capture-of-parameter-pack)
 
 C++20 includes the following new library features:
 - [concepts library](#concepts-library)
@@ -340,6 +341,28 @@ std::string_view to_string(rgba_color_channel my_channel) {
 }
 ```
 
+### Lambda capture of parameter pack
+Capture parameter packs by value:
+```c++
+template <typename... Args>
+auto f(Args&&... args){
+    // BY VALUE:
+    return [...args = std::forward<Args>(args)] {
+        // ...
+    };
+}
+```
+Capture parameter packs by reference:
+```c++
+template <typename... Args>
+auto f(Args&&... args){
+    // BY REFERENCE:
+    return [&...args = std::forward<Args>(args)] {
+        // ...
+    };
+}
+```
+
 ## C++20 Library Features
 
 ### Concepts library
diff --git a/README.md b/README.md
index 62e666e..89a356b 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ C++20 includes the following new language features:
 - [explicit(bool)](#explicitbool)
 - [immediate functions](#immediate-functions)
 - [using enum](#using-enum)
+- [lambda capture of parameter pack](#lambda-capture-of-parameter-pack)
 
 C++20 includes the following new library features:
 - [concepts library](#concepts-library)
@@ -433,6 +434,28 @@ std::string_view to_string(rgba_color_channel my_channel) {
 }
 ```
 
+### Lambda capture of parameter pack
+Capture parameter packs by value:
+```c++
+template <typename... Args>
+auto f(Args&&... args){
+    // BY VALUE:
+    return [...args = std::forward<Args>(args)] {
+        // ...
+    };
+}
+```
+Capture parameter packs by reference:
+```c++
+template <typename... Args>
+auto f(Args&&... args){
+    // BY REFERENCE:
+    return [&...args = std::forward<Args>(args)] {
+        // ...
+    };
+}
+```
+
 ## C++20 Library Features
 
 ### Concepts library