From ce454e0c2d324e9d07c2ceb3be423a7c4e5d4730 Mon Sep 17 00:00:00 2001
From: Anthony Calandra <anthony@anthony-calandra.com>
Date: Sun, 19 Jan 2020 13:48:43 -0500
Subject: [PATCH] Designated initializers; template syntax for lambdas;
 range-based for loop with initializer.

---
 CPP20.md  | 32 ++++++++++++++++++++++++++++++++
 README.md | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/CPP20.md b/CPP20.md
index 67d274e..a1dae93 100644
--- a/CPP20.md
+++ b/CPP20.md
@@ -5,6 +5,9 @@ Many of these descriptions and examples come from various resources (see [Acknow
 
 C++20 includes the following new language features:
 - [concepts](#concepts)
+- [designated initializers](#designated-initializers)
+- [template syntax for lambdas](#template-syntax-for-lambdas)
+- [range-based for loop with initializer](#range-based-for-loop-with-initializer)
 
 C++20 includes the following new library features:
 - [concepts library](#concepts-library)
@@ -163,6 +166,35 @@ concept C = requires(T x) {
 ```
 See also: [concepts library](#concepts-library).
 
+### Designated initializers
+C-style designated initializer syntax. Any member fields that are not explicitly listed in the designated initializer list are default-initialized.
+```c++
+struct A {
+  int x;
+  int y;
+  int z = 123;
+};
+
+A a {.x = 1, .z = 2}; // a.x == 1, a.y == 0, a.z == 2
+```
+
+### Template syntax for lambdas
+Use familiar template syntax in lambda expressions.
+```c++
+auto f = []<typename T>(std::vector<T> v) {
+  // ...
+};
+```
+
+### Range-based for loop with initializer
+This feature simplifies common code patterns, helps keep scopes tight, and offers an elegant solution to a common lifetime problem.
+```c++
+for (auto v = std::vector{1, 2, 3}; auto& e : v) {
+  std::cout << e;
+}
+// prints "123"
+```
+
 ## C++20 Library Features
 
 ### Concepts library
diff --git a/README.md b/README.md
index 596384b..3a361a1 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,9 @@ Many of these descriptions and examples come from various resources (see [Acknow
 
 C++20 includes the following new language features:
 - [concepts](#concepts)
+- [designated initializers](#designated-initializers)
+- [template syntax for lambdas](#template-syntax-for-lambdas)
+- [range-based for loop with initializer](#range-based-for-loop-with-initializer)
 
 C++20 includes the following new library features:
 - [concepts library](#concepts-library)
@@ -255,6 +258,35 @@ concept C = requires(T x) {
 ```
 See also: [concepts library](#concepts-library).
 
+### Designated initializers
+C-style designated initializer syntax. Any member fields that are not explicitly listed in the designated initializer list are default-initialized.
+```c++
+struct A {
+  int x;
+  int y;
+  int z = 123;
+};
+
+A a {.x = 1, .z = 2}; // a.x == 1, a.y == 0, a.z == 2
+```
+
+### Template syntax for lambdas
+Use familiar template syntax in lambda expressions.
+```c++
+auto f = []<typename T>(std::vector<T> v) {
+  // ...
+};
+```
+
+### Range-based for loop with initializer
+This feature simplifies common code patterns, helps keep scopes tight, and offers an elegant solution to a common lifetime problem.
+```c++
+for (auto v = std::vector{1, 2, 3}; auto& e : v) {
+  std::cout << e;
+}
+// prints "123"
+```
+
 ## C++20 Library Features
 
 ### Concepts library
@@ -433,8 +465,8 @@ y; // == 0
 ```
 ```c++
 std::unordered_map<std::string, int> mapping {
-  {"a", 1}, 
-  {"b", 2}, 
+  {"a", 1},
+  {"b", 2},
   {"c", 3},
 };