--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/FixIt/fixit-c++2a.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,49 @@
+// RUN: %clang_cc1 -verify -std=c++2a -pedantic-errors %s
+// RUN: cp %s %t
+// RUN: not %clang_cc1 -x c++ -std=c++2a -fixit %t
+// RUN: %clang_cc1 -Wall -pedantic-errors -x c++ -std=c++2a %t
+// RUN: cat %t | FileCheck %s
+
+/* This is a test of the various code modification hints that only
+   apply in C++2a. */
+template<typename ...T> void init_capture_pack(T ...a) {
+  [x... = a]{}; // expected-error {{must appear before the name}}
+  [x = a...]{}; // expected-error {{must appear before the name}}
+  [...&x = a]{}; // expected-error {{must appear before the name}}
+  [...a]{}; // expected-error {{must appear after the name}}
+  [&...a]{}; // expected-error {{must appear after the name}}
+  [...&a]{}; // expected-error {{must appear after the name}}
+}
+
+namespace constinit_mismatch {
+  extern thread_local constinit int a; // expected-note {{declared constinit here}}
+  thread_local int a = 123; // expected-error {{'constinit' specifier missing on initializing declaration of 'a'}}
+  // CHECK: {{^}}  constinit thread_local int a = 123;
+
+  int b = 123; // expected-note {{add the 'constinit' specifier}}
+  extern constinit int b; // expected-error {{'constinit' specifier added after initialization of variable}}
+  // CHECK: {{^}}  extern int b;
+
+  template<typename> struct X {
+    template<int> static constinit int n; // expected-note {{constinit}}
+  };
+  template<typename T> template<int N>
+  int X<T>::n = 123; // expected-error {{missing}}
+  // CHECK: {{^}}  constinit int X<T>::n = 123;
+
+#define ABSL_CONST_INIT [[clang::require_constant_initialization]]
+  extern constinit int c; // expected-note {{constinit}}
+  int c; // expected-error {{missing}}
+  // CHECK: {{^}}  ABSL_CONST_INIT int c;
+
+#define MY_CONST_INIT constinit
+  extern constinit int d; // expected-note {{constinit}}
+  int d; // expected-error {{missing}}
+  // CHECK: {{^}}  MY_CONST_INIT int d;
+#undef MY_CONST_INIT
+
+  extern constinit int e; // expected-note {{constinit}}
+  int e; // expected-error {{missing}}
+  // CHECK: {{^}}  ABSL_CONST_INIT int e;
+#undef ABSL_CONST_INIT
+}