N3922: direct-list-initialization of an auto-typed variable no longer deduces a

std::initializer_list<T> type. Instead, the list must contain a single element
and the type is deduced from that.

In Clang 3.7, we warned by default on all the cases that would change meaning
due to this change. In Clang 3.8, we will support only the new rules -- per
the request in N3922, this change is applied as a Defect Report against earlier
versions of the C++ standard.

This change is not entirely trivial, because for lambda init-captures we
previously did not track the difference between direct-list-initialization and
copy-list-initialization. The difference was not previously observable, because
the two forms of initialization always did the same thing (the elements of the
initializer list were always copy-initialized regardless of the initialization
style used for the init-capture).

llvm-svn: 252688

1 files changed, 4 insertions, 2 deletions

diff --git a/clang/test/SemaCXX/cxx0x-initializer-stdinitializerlist.cpp b/clang/test/SemaCXX/cxx0x-initializer-stdinitializerlist.cpp
index 9456dd713aa..3d119643710 100644
--- a/clang/test/SemaCXX/cxx0x-initializer-stdinitializerlist.cpp
+++ b/clang/test/SemaCXX/cxx0x-initializer-stdinitializerlist.cpp
@@ -117,8 +117,10 @@ void argument_deduction() {
 
 void auto_deduction() {
   auto l = {1, 2, 3, 4};
-  auto l2 {1, 2, 3, 4}; // expected-warning {{will change meaning in a future version of Clang}}
+  auto l2 {1, 2, 3, 4}; // expected-error {{initializer for variable 'l2' with type 'auto' contains multiple expressions}}
+  auto l3 {1};
   static_assert(same_type<decltype(l), std::initializer_list<int>>::value, "");
+  static_assert(same_type<decltype(l3), int>::value, "");
   auto bl = {1, 2.0}; // expected-error {{cannot deduce}}
 
   for (int i : {1, 2, 3, 4}) {}
@@ -190,7 +192,7 @@ namespace rdar11948732 {
 }
 
 namespace PR14272 {
-  auto x { { 0, 0 } }; // expected-error {{cannot deduce actual type for variable 'x' with type 'auto' from initializer list}}
+  auto x { { 0, 0 } }; // expected-error {{cannot deduce type for variable 'x' with type 'auto' from nested initializer list}}
 }
 
 namespace initlist_of_array {