Allow a conversion from the empty initializer list {} to an

std::initializer_list<T> so long as <T> is known. This conversion has
identity rank.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154065 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 7afa39f3f3..e4c6fdfb59 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -4301,6 +4301,16 @@ TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
               ImplicitConversionSequence::Worse)
         Result = ICS;
     }
+
+    // For an empty list, we won't have computed any conversion sequence.
+    // Introduce the identity conversion sequence.
+    if (From->getNumInits() == 0) {
+      Result.setStandard();
+      Result.Standard.setAsIdentityConversion();
+      Result.Standard.setFromType(ToType);
+      Result.Standard.setAllToTypes(ToType);
+    }
+
     Result.setListInitializationSequence();
     Result.setStdInitializerListElement(toStdInitializerList);
     return Result;