[c++20] P0780R2: Support pack-expansion of init-captures.

This permits an init-capture to introduce a new pack:

  template<typename ...T> auto x = [...a = T()] { /* a is a pack */ };

To support this, the mechanism for allowing ParmVarDecls to be packs has
been extended to support arbitrary local VarDecls.

llvm-svn: 361300

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/test/FixIt/fixit-c++2a.cpp b/clang/test/FixIt/fixit-c++2a.cpp
new file mode 100644
index 00000000000..c97bb7ae610
--- /dev/null
+++ b/clang/test/FixIt/fixit-c++2a.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -verify -std=c++2a %s
+// RUN: cp %s %t
+// RUN: not %clang_cc1 -x c++ -std=c++2a -fixit %t
+// RUN: %clang_cc1 -Wall -pedantic -x c++ -std=c++2a %t
+
+/* 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}}
+}